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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that .
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re : energy level : could someone please explain the rationale behind the promotion of 1s and demotion of 2p rendering one p orbital unhybridized ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons .
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could someone please explain the electron configuration of boron why are there 3 sp2 and an unhybridized p orbital ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals .
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how come an atom `` naturally '' promote its electron from 2s orbital to 2p orbital ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens .
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why is there only one electron in the 2s orbital of carbon ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital .
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i am still not clear about how can we obtain 2 un-hybridized orbitals for each carbon atom when there are 3 hybrid orbitals present with it ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that .
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why is 2s with only one electron at the beginning ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell .
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at 1.27 why did we take only two p orbitals ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now .
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why does the hybridised lobe shorten due to increase in electron density ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond .
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are all sigma bonds also covalent bonds ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that .
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will the not-hybridized p orbital be called the lone pair ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three .
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if you want to calculate the steric number before you think about hybridization ... in the case of methane , how can we know that only 3 of 4 bonds are sigma ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character .
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effect the strength of the bond similarly to the way that a polar covalent bond is stronger than a non-polar covalent bond ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule .
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the electron configuration for carbon is 2s^2 sp^2 ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here .
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will the orbitals in boron changes from sp2 hybridization to sp3 hybridization after accepting a pair of electron ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons .
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for bf3 , i do n't get why you only drew the unhybridized p orbital , what about other sp2 orbitals ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals .
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are there any type of bond other than sigma and pi bond ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react .
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are all lewis acid follow the same principal ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three .
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what is the steric number used for ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine .
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why the angles between orbital in bf3 are 120 degree ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine .
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so why are the bonds in bf3 in the same plane ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that .
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p orbital is in higher energy level so distance between bond it form between atoms should be more than ones bonded by sp^2 hybridized orbital .to make sense if two thing are connected with ropes one longer and other shorter and both properly straight than we see a curve of ropes .in the same way the molecule should be curved a little bit ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule .
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0 are n't there 4 bonds on every carbon ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched .
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why do the carbon atoms in graphite get sp2 hybridized , even though there are no double bonds between the atoms ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine .
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does n't bf3 have 9 lone pairs of elcetrons ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms .
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what is the order of energies of sp3 , sp2 and sp orbitals ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that .
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why draw in 2 dumbbell-shaped unhybridized p orbital on each of the cwrbon atoms , i thought it should be one as we have only one unhybridized p orbital ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon .
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how did you determine the distance between the carbons ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too .
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why would the s-orbital be promoted rather than just letting the 3 p-orbitals remain and bond with the hydrogen ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too .
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why would the s-orbital be promoted rather than just letting the 3 p-orbitals remain and bond with the hydrogen ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that .
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do we do the configuration for only one carbon atom ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here .
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can pi bonds be formed between hybridized orbitals as well as unhybridized ones , like in the video ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule .
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just for my own clarification , does the pi bond also contribute to the shortened bond length ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule .
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or do pi bonds not have a significant effect on bond length at all ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one .
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if boron has electron configuration 1s2 2s2 2p1 , why is it forming sp2 hybrid shells instead of ps2 hybrid shells since two atoms are coming from the 2s orbital and only one is coming from the 2p orbitals ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine .
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why does bf3 have an empty p orbital or even have it at all ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees .
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is there a way to work out the geometric structure mathematically like how some are planar etc ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero .
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why are there 0 lone pairs around boron ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here .
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does sp3 , sp2 and sp1 hybridization only work with certain atoms ( so far we 've only seen atoms used from the second row of the periodic table ) ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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at the beginning of the video , why is the configuration for carbon different to the one in the sp3 hybridization video ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon .
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do the number of valence electrons change after hybridization ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here .
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how co2 has sp2 hybridization ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three .
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how are you calculating the angstrom number ?
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: in an earlier video , we saw that when carbon is bonded to four atoms , we have an sp3 hybridization with a tetrahedral geometry and an ideal bonding over 109.5 degrees . if you look at one of the carbons in ethenes , let 's say this carbon right here , we do n't see the same geometry . the geometry of the atoms around this carbon happens to be planar . actually , this entire molecule is planar . you could think about all this in a plane here . and the bond angles are close to 120 degrees . approximately , 120 degree bond angles and this carbon that i 've underlined here is bonded to only three atoms . a hydrogen , a hydrogen and a carbon and so we must need a different hybridization for each of the carbon 's presence in the ethylene molecule . we 're gon na start with our electron configurations over here , the excited stage . we have carbons four , valence electron represented . one , two , three and four . in the video on sp3 hybridization , we took all four of these orbitals and combined them to make four sp3 hybrid orbitals . in this case , we only have a carbon bonded to three atoms . we only need three of our orbitals . we 're going to promote the s orbital . we 're gon na promote the s orbital up and this time , we only need two of the p orbitals . we 're gon na take one of the p 's and then another one of the p 's here . that is gon na leave one of the our p orbitals unhybridized . each one of these orbitals has one electron and it 's like that . this is no longer an s orbital . this is an sp2 hybrid orbital . this is no longer a p orbital . this is an sp2 hybrid orbital and same with this one , an sp2 hybrid orbital . we call this sp2 hybridization . let me go and write this up here . and use a different color here . this is sp2 hybridization because we 're using one s orbital and two p orbitals to form our new hybrid orbitals . this carbon right here is sp2 hybridized and same with this carbon . notice that we left a p orbital untouched . we have a p orbital unhybridized like that . in terms of the shape of our new hybrid orbital , let 's go ahead and get some more space down here . we 're taking one s orbital . we know s orbitals are shaped like spheres . we 're taking two p orbitals . we know that a p orbital is shaped like a dumbbell . we 're gon na take these orbitals and hybridized them to form three sp2 hybrid orbitals and they have a bigger front lobe and a smaller back lobe here like that . once again , when we draw the pictures , we 're going to ignore the smaller back lobe . this gives us our sp2 hybrid orbitals . in terms of what percentage character , we have three orbitals that we 're taking here and one of them is an s orbital . one out of three , gives us 33 % s character in our new hybrid sp2 orbital and then we have two p orbitals . two out of three gives us 67 % p character . 33 % s character and 67 % p character . there 's more s character in an sp2 hybrid orbital than an sp3 hybrid orbital and since the electron density in an s orbital is closer to the nucleus . we think about the electron density here being closer to the nucleus that means that we could think about this lobe right here being a little bit shorter with the electron density being closer to the nucleus and that 's gon na have an effect on the length of the bonds that we 're gon na be forming . let 's go ahead and draw the picture of the ethylene molecule now . we know that each of the carbons in ethylenes . just going back up here to emphasize the point . each of these carbons here is sp2 hybridized . that means each of those carbons is going to have three sp2 hybrid orbitals around it and once unhybridized p orbital . let 's go ahead and draw that . we have a carbon right here and this is an sp2 hybridized orbitals . we 're gon na draw in . there 's one sp2 hybrid orbital . here 's another sp2 hybrid orbital and here 's another one . then we go back up to here and we can see that each one of those orbitals . let me go ahead and mark this . each one of those sp2 hybrid orbitals has one electron in it . each one of these orbitals has one electron . i go back down here and i put in the one electron in each one of my orbitals like that . i know that each of those carbons is going to have an unhybridized p orbital here . an unhybridized p orbital with one electron too . let me go ahead and draw that in . i 'll go ahead and use a different color . we have our unhybridized p orbital like that and there 's one electron in our unhybridized p orbital . each of the carbons was sp2 hybridized . let me go ahead and draw the dot structure right here again so we can take a look at it . the dot structure for ethylene . let 's do the other carbon now . the carbon on the right is also sp2 hybridized . we can go ahead and draw in an sp2 hybrid orbital and there 's one electron in that orbital and then there 's another one with one electron and then here 's another one with one electron . this carbon being sp2 hybridized also has an unhybridized p orbital with one electron . go ahead and draw in that p orbital with its one electron . we also have some hydrogens . we have some hydrogens to think about here . each carbon is bonded to two hydrogens . let me go ahead and put in the hydrogens . the hydrogen has a valance electron in an unhybridized s orbital . i 'm going ahead and putting in the s orbital and the one valance electron from hydrogen like this . when we take a look at what we 've drawn here , we can see some head on overlap of orbitals , which we know from our earlier video is called a sigma bond . here 's the head on overlap of orbitals . that 's a sigma bond . here 's another head on overlap of orbitals . the carbon carbon bond , here 's also a head on overlap of orbitals and then we have these two over here . we have a total of five sigma bonds in our molecules . let me go ahead and write that over here . there are five sigma bonds . if i would try to find those on my dot structure this would be a sigma bond . this would be a sigma bond . one of these two is a sigma bond and then these over here . a total of five sigma bonds and then we have a new type of bonding . these unhybridized p orbitals can overlap side by side . up here and down here . we get side by side overlap of our p orbitals and this creates a pi bond . a pi bond , let me go ahead and write that here . a pi bond is side by side overlap . there is overlap above and below this sigma bond here and that 's going to prevent free rotation . when we 're looking at the example of ethane , we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here , this pi bond is going to prevent rotations so we do n't get different confirmations of the ethylene molecules . no free rotation due to the pi bonds . when you 're looking at the dot structure , one of these bonds is the pi bonds , i 'm just gon na say it 's this one right here . if you have a double bond , one of those bonds , the sigma bond and one of those bonds is a pi bond . we have a total of one pi bond in the ethylene molecule . if you 're thinking about the distance between the two carbons , let me go ahead and use a different color for that . the distance between this carbon and this carbon . it turns out to be approximately 1.34 angstroms , which is shorter than the distance between the two carbons in the ethane molecule . remember for ethane , the distance was approximately 1.54 angstroms . a double bond is shorter than a single bond . one way to think about that is the increased s character . this increased s character means electron density is closer to the nucleus and that 's going to make this lobe a little bit shorter than before and that 's going to decrease the distance between these two carbon atoms here . 1.34 angstroms . let 's look at the dot structure again and see how we can analyze this using the concept of steric number . let me go ahead and redraw the dot structure . we have our carbon carbon double bond here and our hydrogens like that . if you 're approaching this situation using steric number remember to find the hybridization . we can use this concept . steric number is equal to the number of sigma bonds plus number of lone pairs of electrons . if my goal was to find the steric number for this carbon . i count up my number of sigma bonds . that 's one , two and then i know when i double bond one of those is sigma and one of those is pi . one of those is a sigma bond . a total of three sigma bonds . i have zero loan pairs of electrons around that carbon . three plus zero , gives me a steric number of three . i need three hybrid orbitals and we 've just seen in this video that three sp2 hybrid orbitals form if we 're dealing with sp2 hybridization . if we get a steric number of three , you 're gon na think about sp2 hybridization . one s orbital and two p orbitals hybridizing . that carbon is sp2 hybridized and of course , this one is too . both of them are sp2 hybridized . let 's do another example . let 's do boron trifluoride . bf3 . if you wan na draw the dot structure of bf3 , you would have boron and then you would surround it with your flourines here and you would have an octet of electrons around each flourine . i go ahead and put those in on my dot structure . if your goal is to figure out the hybridization of this boron here . what is the hybridization stage of this boron ? let 's use the concept of steric number . once again , let 's use steric number . find the hybridization of this boron . steric number is equal to number of sigma bonds . that 's one , two , three . three sigma bonds plus lone pairs of electrons . that 's zero . steric number of three tells us this boron is sp2 hybridized . this boron is gon na have three sp2 hybrid orbitals and one p orbital . one unhybridized p orbital . let 's go ahead and draw that . we have a boron here bonded to three flourines and also it 's going to have an unhybrized p orbital . now , remember when you are dealing with boron , it has one last valance electron and carbon . carbon have four valance electrons . boron has only three . when you 're thinking about the sp2 hybrid orbitals that you create . sp2 hybrid orbital , sp2 , sp2 and then one unhybridized p orbital right here . boron only has three valance electrons . let 's go ahead and put in those valance electrons . one , two and three . it does n't have any electrons in its unhybridized p orbital . over here when we look at the picture , this has an empty orbital and so boron can accept a pair of electrons . we 're thinking about its chemical behavior , one of the things that bf3 can do , the boron can accept an electron pair and function as a lewis acid . that 's one way in thinking about how hybridizational allows you to think about the structure and how something might react . this boron turns out to be sp2 hybridized . this boron here is sp2 hybridized and so we can also talk about the geometry of the molecule . it 's planar . around this boron , it 's planar and so therefore , your bond angles are 120 degrees . if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles . in the next video , we 'll look at sp hybridization .
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if you have boron right here and you 're thinking about a circle . a circle is 360 degrees . if you divide a 360 by 3 , you get 120 degrees for all of these bond angles .
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why 360 angle is not formed in carbocation ?
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( piano playing ) dr. steven zucker : by the time titian painted christ crowned with thorns , he was towards the end of his very long career . he was the greatest artist of the venetian renaissance and he was applying paint in a way that artists had never done before . dr. beth harris : and you could imagine after decades of painting that you have a familiarity and an intimacy with your materials . it was said that titian used his hands to paint at the end of his career . steven : we actually have a sense that that might have been the case here . look how heavy that paint is as it moves across the surface . beth : we see torches in the upper right and you can see the thickness of the white and gold paint , gives us a sense of flickering light and of the chaos of this moment . steven : you have these figures that emerge from darkness . he 's able to convey a kind of aggression , a kind of energy . this is not the static renaissance any longer and there 's a dynamism and power that is really at odds with the way in which we think about the renaissance . beth : it 's almost proto baroque , meaning that it looks toward the baroque and it 's interest in movement and also in the way that everything is taking place very close to us and seems to move out into our space . steven : the drama is something that i associate with a baroque and he is achieving that , not only by the use of diagonals , not only by the activation and the violence that 's being rendered , but also by the really stark contrast between light and dark . beth : it 's funny that you use the word violence because to me , this painting is n't all that violent . we know that we 're looking at christ having the crown of thorns , this painful thing put on his head . steven : right , this is the passion , that is the events at the end of christs life that culminate in the crucifixion . beth : right , these moments of christ 's terrible suffering , but i do n't see titian focusing on the blood and gore of the event like someone like rubens will do . steven : that 's true . look at the figure of christ . even for all the activity , there 's also a kind of static quality , at least in that central figure . beth : we see christ twisting his body in an unnatural way and he seems very resigned . steven : i 'm interested in the way in which it is both violent and elegant simultaneously . look at those diagonal sticks . a figure in the back right really is plunging that stick and there is a real sense of violence and yet the stick is not actually catching the thorns , it 's not actually catching christs head . it 's somehow moving past . beth : their positions seem dance like instead of serious violent movement . steven : that 's the perfect word , dance like . look at the figure on the extreme left . he could n't be rendered in a more brutish way and yet he 's elegantly up on the balls of his feet , his knees are bent , there is a balance and lightness that is really at odds with what he 's meant to represent . beth : well , look at that figure in the lower right who strides up these stairs with a stick in one hand and an ax in the other , but his arm curls up , his head leans to the right . this is a position that looks more like choreography than actual movement and these are all characteristics that remind us of mannerism and this is 1570 . after all , mannerism begins in the 1520 's , 1530 's , 1540 's , right at the time of the reformation . this is a time of real spiritual upheaval in europe and perhaps we 're seeing that reflected here . steven : it 's a kind of anti-naturalism . there is something very theatrical about it . there is something very invented about it . beth : and in some ways we ca n't even read the forms of the bodies . not only has titian embedded everything in darkness and the shallow space , but for example , we ca n't read the right leg of that standing figure on the left or similarly the right leg of the figure who 's striding up from the lower right . so , space becomes incomprehensible , which is also a characteristic of mannerism . steven : when you look at a painting like this you can see the tremendous impact that this artist had on later painters . i 'm looking at velazquez rubens rembrant and , of course , caravaggio . all these artists are looking back to titian and this extraordinary achievement , in a sense , the freedom that titian is allowing for generations of artists . freeing them from the strictures of balance and harmony and clarity that had been hallmarks of the renaissance . beth : so , this is an interesting moment of transitioning from the renaissance . we see elements of mannerism and we also see elements of the baroque that is just to come . ( piano playing )
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he was the greatest artist of the venetian renaissance and he was applying paint in a way that artists had never done before . dr. beth harris : and you could imagine after decades of painting that you have a familiarity and an intimacy with your materials . it was said that titian used his hands to paint at the end of his career .
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maybe you guys could bring examples of not-so-great paintings from the various eras so that we can appreciate what makes the great great and the common common ?
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( piano playing ) dr. steven zucker : by the time titian painted christ crowned with thorns , he was towards the end of his very long career . he was the greatest artist of the venetian renaissance and he was applying paint in a way that artists had never done before . dr. beth harris : and you could imagine after decades of painting that you have a familiarity and an intimacy with your materials . it was said that titian used his hands to paint at the end of his career . steven : we actually have a sense that that might have been the case here . look how heavy that paint is as it moves across the surface . beth : we see torches in the upper right and you can see the thickness of the white and gold paint , gives us a sense of flickering light and of the chaos of this moment . steven : you have these figures that emerge from darkness . he 's able to convey a kind of aggression , a kind of energy . this is not the static renaissance any longer and there 's a dynamism and power that is really at odds with the way in which we think about the renaissance . beth : it 's almost proto baroque , meaning that it looks toward the baroque and it 's interest in movement and also in the way that everything is taking place very close to us and seems to move out into our space . steven : the drama is something that i associate with a baroque and he is achieving that , not only by the use of diagonals , not only by the activation and the violence that 's being rendered , but also by the really stark contrast between light and dark . beth : it 's funny that you use the word violence because to me , this painting is n't all that violent . we know that we 're looking at christ having the crown of thorns , this painful thing put on his head . steven : right , this is the passion , that is the events at the end of christs life that culminate in the crucifixion . beth : right , these moments of christ 's terrible suffering , but i do n't see titian focusing on the blood and gore of the event like someone like rubens will do . steven : that 's true . look at the figure of christ . even for all the activity , there 's also a kind of static quality , at least in that central figure . beth : we see christ twisting his body in an unnatural way and he seems very resigned . steven : i 'm interested in the way in which it is both violent and elegant simultaneously . look at those diagonal sticks . a figure in the back right really is plunging that stick and there is a real sense of violence and yet the stick is not actually catching the thorns , it 's not actually catching christs head . it 's somehow moving past . beth : their positions seem dance like instead of serious violent movement . steven : that 's the perfect word , dance like . look at the figure on the extreme left . he could n't be rendered in a more brutish way and yet he 's elegantly up on the balls of his feet , his knees are bent , there is a balance and lightness that is really at odds with what he 's meant to represent . beth : well , look at that figure in the lower right who strides up these stairs with a stick in one hand and an ax in the other , but his arm curls up , his head leans to the right . this is a position that looks more like choreography than actual movement and these are all characteristics that remind us of mannerism and this is 1570 . after all , mannerism begins in the 1520 's , 1530 's , 1540 's , right at the time of the reformation . this is a time of real spiritual upheaval in europe and perhaps we 're seeing that reflected here . steven : it 's a kind of anti-naturalism . there is something very theatrical about it . there is something very invented about it . beth : and in some ways we ca n't even read the forms of the bodies . not only has titian embedded everything in darkness and the shallow space , but for example , we ca n't read the right leg of that standing figure on the left or similarly the right leg of the figure who 's striding up from the lower right . so , space becomes incomprehensible , which is also a characteristic of mannerism . steven : when you look at a painting like this you can see the tremendous impact that this artist had on later painters . i 'm looking at velazquez rubens rembrant and , of course , caravaggio . all these artists are looking back to titian and this extraordinary achievement , in a sense , the freedom that titian is allowing for generations of artists . freeing them from the strictures of balance and harmony and clarity that had been hallmarks of the renaissance . beth : so , this is an interesting moment of transitioning from the renaissance . we see elements of mannerism and we also see elements of the baroque that is just to come . ( piano playing )
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steven : i 'm interested in the way in which it is both violent and elegant simultaneously . look at those diagonal sticks . a figure in the back right really is plunging that stick and there is a real sense of violence and yet the stick is not actually catching the thorns , it 's not actually catching christs head .
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what important part do these sticks play in crowning christ with thorns ?
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this exhibition assembles more than a hundred works of art made by abstract expressionist artists in the 1940s , 50s , and 60s . what 's amazing to me is they all come from the collection of this museum . for me , it was very important to do this exhibition -- for two reasons . one is the sheer pleasure and the sheer , i felt , importance of , fifty or sixty years later , looking again at abstract expressionism . it 's become something so identified with new york and with moma ( the museum of modern art ) , and something that we take for granted -- almost as much as we take something like french impressionism for granted . like , `` oh yes , those beautiful landscapes by monet . '' and i thought , over the last year or two , that this is painting and sculpture that we need to look at again , and -- now that it 's the 21st century -- see what of it really carries forward its message into this next century . it 's been a long time now since that work got a serious reconsideration . i think it 's going to be exhilarating , frankly , to see the power of these objects in the galleries -- the ambition , the sheer majesty and grandeur of this art -- because that 's very much what its creators wanted it to be , is something that is knocking my socks off , anyway , all over again . but the other reason that i wanted to do this exhibition is to point out to our visitors that what you normally see at the museum of modern art , you 're seeing the tip of an iceberg . the real museum of modern art is not what you see on the walls and the galleries when you 're walking through as a visitor . the real museum of modern art is in our drawing center , in our print center , in our photography study center , where there are just hundreds and thousands of works of art that we 've collected over the decades , but that obviously there is n't a space to show on a regular basis . so for me , this is actually quite a thrilling opportunity to have our visitors get the chance to walk through what is actually , in total , 25,000 square feet worth of gallery space -- all devoted to one subject -- that people can immerse themselves in , can really dig into . instead of just seeing the normal two or three paintings by mark rothkoe , see ten paintings by mark rothkoe . instead of just seeing the big names like mark rothkoe or jackson pollock , see works by artists such as jack tworkov , william baziotes , grace hartigan , lee krasner -- people who were incredibly important at that time , and who had major , major impact on their peers . and yet , over time , their names have not been remembered as well . the museum of modern art is often very closely identified with abstract expressionism . we were on hand for abstract expressionism 's birth . in small part , at least , one can say , because moma did exist , and because moma was here to show that art from the first half of the century by european greats , such as matisse and picasso -- to young artists at work in new york . although we are so closely identified with abtract expressionism today -- ( and , indeed , our collection is the richest in the world . ) -- in the beginning , this museum was slow to come to abstract expressionism . it was not obvious at the end of the 40s that this was a movement that had some kind of coherence , and was going to be as great , if not greater , than these earlier european avant gardes . we did buy a painting by a pollock -- a painting by pollock -- from his first show at the peggy guggenheim gallery in 1943 . and we made other historic purchases like that . in fact , our first rothkoe painting , which was offered as a gift from a trustee , ( philip johnson , the architect , in fact , in 1952 ) caused another trustee to resign in disgust . the early trustees and the early audience was not necessarily ready for abstract expressionism . and so i think the curators were conscious of that , and wanted to take it slow . in 1958 , we organized an exhibition called 'the new american painting . ' it toured to eight countries in europe . the influence of that exhibition was enormous on painters in france , switzerland , england , spain , italy , etc . and when that exhibition was done with its tour , it came back and was here at moma in 1959 -- 'the new american painting . ' and that kind of sealed the movement as a great , important art historical phenomenon of the 20th century .
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this exhibition assembles more than a hundred works of art made by abstract expressionist artists in the 1940s , 50s , and 60s . what 's amazing to me is they all come from the collection of this museum .
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i was wondering if anyone knew of any good books that i could read on abstract impressionism , or biographies of the artists , pollock , rothko , kline , newman etc ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells .
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1 tunica intima 2tunica media 3 tunica externa here only tunica intima ( endothelial cells+basement membrane ) is mentioned , what becomes of the other two layers ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
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so the diffusion of ions and such into the bowman 's capsule from the glomerulus is an example of passive transport ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ?
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are there actually pores through the cells , or is it that there is more space between cells ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron .
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i am not sure when he exactly answered this question on this video , but just to be clear ; what makes glomerulus arteries more efficient at draining filtrate than just the general arteries and why arteries do n't drain as much water as glomerulus ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells .
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are those fenestrated endothelial cells and epithelial cells are structural characteristics only unique to glomerulus arteries ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells .
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so does every vessel in our body have endothelial cells , tubule cells , and basement membrane ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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why is there no mention of glomerular capillaries ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus .
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should n't it be described as afferent arteriole leading to glomerular capillary leading to efferent arteriole ?
|
: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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explain the term glomerular filtration rate , what is it and how can you measure it ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron .
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if we drain all the fluid out , would n't our blood become super dehydrated and dry ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs .
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glomerular filtration refers to the volume of blood that is filtered into the bowman 's capsule , right ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
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what if someone 's blood cell enters the bowman 's capsule , will it be a chain reaction ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there .
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more and more red blood cells will be excreted ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus .
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do the kidneys have many nephrons or just one ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells .
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are there gap junctions between the endothelial cells of the arteriole ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron .
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is glomerular filtration passive transport ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there .
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i 'm just unsure about if the filtrate is the stuff that does n't go in ( red blood cells ) or if it is like urea ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
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is there any special purpose of why wbc 's and rbc 's leak ( i mean why do they even have to pass through those membranes and enter the bowman 's capsule ) ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
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is there any special purpose of why wbc 's and rbc 's leak ( i mean why do they even have to pass through those membranes and enter the bowman 's capsule ) ?
|
: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
|
so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
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is there any special purpose of why wbc 's and rbc 's leak ( i mean why do they even have to pass through those membranes and enter the bowman 's capsule ) ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
|
is there any special purpose of why wbc 's and rbc 's leak ( i mean why do they even have to pass through those membranes and enter the bowman 's capsule ) ?
|
: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron .
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is glomerular filtration related to urine formation ?
|
: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
|
: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron .
|
is glomerular filtration related to urine formation ?
|
: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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how is a kidney glomerulus podocyte an example of a eukaryotic cell ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here .
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are podocytes part of the bowman 's capsule ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . ''
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the renal calyces = minor calyces and major calyces ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron .
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is there any relationship between glomerular filtration rate , renal blood/plasma flow and filtration index ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron .
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or simply putting it : what will be the effect on glomerular filtration rate and filtration index if renal blood/plasma flow is increased ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ?
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.those itchy burning senation after you eat be the kidneys not functioning well ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space .
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can our blood leak through the endothelial cell and the basement membrane ... if yes.. where does it go ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells .
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are all endothelial cells fenestrated , or is this is characteristic special to the glomerulus ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here .
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what is the purpose of the glomerulus ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule .
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does high blood pressure cause some proteins to be forced through the basement membrane ?
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: all right , so i think we have a pretty decent appreciation of renal anatomy ; we know how the kidney is structured , now we just need to take a look at some of the finer details . we started talking about the nephron , which i kinda drew right here , and we said , `` this is the functional unit of filtration `` and collection in the kidney . '' so let 's start off with the very beginning of the nephron . the first part of the nephron is called the `` glomerulus '' ; it receives branches that come off the renal artery , you see a branch going that a way ; there 's a branch going this a way , and just like any artery , it branches off into arterioles , and it 's an arteriole that comes up first to meet the glomerulus . so if we look down here , we 're going to have something that came off of the renal artery , that 's an arteriole , so i 'll write , `` arteriole , '' right here , and we actually further specify this : we call this the `` afferent arteriole , '' `` afferent '' meaning , `` going towards . '' and so , this is the afferent arteriole , or the arteriole that 's going towards the glomerulus . the glomerulus then , is this really loopy structure ; there 's a lot of spinning that goes on here , then we branch off again , and this gives us the same arteriole , this is the same vessel we just started off with , so we 're going this way , and spinning around and coming out , as one single vessel , but we call this part of it , the `` efferent '' arteriole : `` efferent , '' meaning that we have left the glomerulus . and that of course leaves this ball-like structure over here , that 's going to be known as the glomerulus . now the thing about the glomerulus that 's really interesting : it 's the main site for filtration , where we take blood that came in from the renal artery , and we push out a whole bunch of fluid , that we 're then going to take out some ions , and some water , and some waste , and we 'll get rid of the waste or the extra ions . the glomerulus is where we take blood and turn it into filtrate , and let the rest of the blood flow on . so this efferent arteriole is gon na turn into a capillary , and then it 's gon na go into venules , and then collect back , and come out as the renal vein ; we 'll talk about that in a later video , when i talk about other parts of the nephron . the glomerulus though , just leaks out fluid , and it needs to be caught somewhere . that fluid that leaks out is caught in a capsule , that 's kind of hugging the glomerulus right here . so i 'm gon na draw it , like that , and it kinda keeps going this way , and this is gon na continue on , into the rest of our nephron , but this thing right here , it 's a capsule , and actually it has a name ; it 's named after a british scientist , `` doctor bowman , '' so we call this , `` bowman 's capsule . '' this is bowman 's capsule , and this is where we 're going to collect the filtrate , or the fluid that comes out of the glomerululs . the inside right here is just open space , so they call it , `` bowman 's space '' as well , so it 's just space that 's gon na collect our filtrate . so at this point , you should be asking yourself , `` why is it that we 're gon na have fluid leak out here ? `` i mean , there 's all this wrapping that goes around , `` so we 've got high pressure , but how is this different `` from other arterioles in our body ? `` why is it that we have so much leakage , `` purposefully happening here , `` but it does n't happen everywhere else in our body ? '' so let me answer your question , and why do n't we just blow up that part , right here , and open this window so we can take a better look . so the point where the arteriole meets bowman 's capsule , there 's a lot going on . recall , that when we have a vessel , i 'll draw half of it , like that , right there , and it 's kind of going this a way , okay , so that 's our vessel that 's right here . this vessel 's got a lot of good stuff , like our red blood cells , our white blood cells , platelets , some really really big proteins , so i 'm just gon na draw something really big , right here ; that 's a giant protein , and it 's not gon na leak out into our bowmans ' capsule . so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ? so our vessels , our arterioles , just like anything else in our body ; they 're made up of cells . and the cells that line our vessels over here , i 'll just draw a whole bunch of these guys , kinda hanging out , so these guys are called , `` endothelial cells '' ; each of these is an endothelial cell . so an endothelial cell is a lot like most of our eukaryotic cells : they 've got a nucleus , and they 've got all their organelles , and stuff like that goin ' on ; i 'm not gon na go into that kinda detail for right now , but just recall that they 're eukaryotic cells . now something that 's special about these vessels , is that they 're fenestrated . write that in parenthesis , `` fenestrated , '' and if you do n't know what this term means , all it means is that these vessels have a lot of holes ; they 're very `` holey , '' and so , because of that , the holes allow small things like sodium , and amino acids , and glucose to leak through , so it 's got some holes in them , you know , the way that they 're sort of connected . so there are holes where these guys can kinda slip through . and actually some of these holes can allow bigger proteins to come through , but these proteins still do n't , because there 's another added layer , that sits in between these endothelial cells in the in the tuble , so this is sort of another membrane that 's right here . i 'll just kinda draw it shaded in , like this , and it 's not a complete barrier ; it 's semi-permeable , meaning some things can leak through , but this is another membrane , that we call , the `` basement membrane '' ; this is a basement membrane , and you may have heard about this in other contexts . so the basement membrane right here , helps to make sure that small things pass through : things like sodium can get through these fenestrations , and leak out ; our amino acids can do the same ; and our glucose can , at times , as well ; but these bigger proteins bounce back ; they bounce back , because either they ca n't make it through the fenestrations , or the basement membrane prevents them from leaking into bowman 's space . and then finally , we 've got the tubular cells , tubular cells that make up the interaction point on the end of the bowman 's capsule . so they sort of look like this ; they 're pretty long cells , and the funny thing about them is that some of these guys actually hug the vessel ; they hug the endothelial cells , like that . and so , they 're sort of like these legs ; this is sort of a leg-like projection , and so , if you remember a doctor you might see , if you 've got problems with your feet is a `` podiatrist , '' and so this type of cell , we call these `` podocytes '' right , `` podo '' meaning `` foot . '' podocytes , and so there are some podocytes , in addition to these tubular cells , there are some that are just tubule cells . and another term for that , is just an `` epithelial cell '' ; this is an epithelial cell , okay ? and so , we go from the endothelial cell , to the epithelial cell , and i think i should also mention that these podocytes are a certain class of epithelial cell , as well , and so , these guys hug around the arteriole ; that sort of helps for this connection to stay close .
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so , this stuff kinda moves along that way , then again , we 've got other things like ions , so i 'm gon na write , `` sodium '' right there . we 've also got smaller protein sub-units , like amino acids ; i 'll just write , `` aa , '' and we 've also got glucose in here . these are things that can leak out , so how is it they get from the arteriole , into bowman 's space ?
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is that how excess protein gets into urine ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides .
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if acetyl chloride reacts so violently with water , then how is it formed ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that .
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why would the product even form if it readily reacts with the water that it would produce ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride .
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so to name acids we have to know the anions names but how do we identify the anion names like ide , ate , or ite ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example .
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what about when we are not talking about polyatomic ions like just bromine how would we identify if its name is bromide , or bromate , or bromite ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids .
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why do acid anhydrides has higher priority than acyl halides when in fact acyl halides are more reactive than anhydrides ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name .
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can we use benzene carboxylic anhydride instead of using benzoic anhydride ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive .
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why would rcocl react violently with water ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name .
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if you choose the iupac naming , does the acetic benzoic anhydride change to benzoic ethanoic anhydride ?
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lecturer : the next few videos we 're going to look at the nomenclature and properties of carboxylic acid derivatives . let 's start with an acyl halide . here 's our general structure of an acyl halide . on the left side we have an acyl group , on the right side we have a halogen . you could also call this acid halides . they 're derived from carboxylic acids . if we look at this carboxylic acid on the left here , a two carbon carboxylic acid , we could convert that to a two carbon acyl halide over here on the right . if we want to name our acyl halide we have to think about the name of the carboxylic acid . this , of course , is acetic acid . let 's go ahead and write out acetic acid here . if we want to name the corresponding acyl halide we need to think about dropping the -ic ending , and then the acid . we drop -ic and acid , and we add -yl and then the halide . let 's go ahead and write that out , so we drop the -ic and we add the yl and then we add the halide . we have a chlorine here so we 're going to write chloride . we would call this acetyl chloride . let 's go ahead and show that right here . we add the -yl and then we add the halide portion . we could have also called this ethanoic acid . ethanoic acid would be the iupac name but everyone says acetic acid . if we were to call this ethanoic acid , once again think about drop your -ic and then the acid part , drop this portion , then add -yl and then chloride . let 's go ahead and write that in here . we go ahead and add the -yl in and then the chloride like that . that would be ethanoyl chloride as our name . let 's go ahead and show this portion , once again , the -yl portion and then our halide . in terms of physical properties of acyl halides we need to think about the interaction of two molecules here . let me go ahead and draw in another molecule of acetyl chloride . acetyl chloride has a boiling point of approximately 51 degrees celsius . let me go ahead and write that in , so approximately 51 degrees celsius . we know that acetyl chloride is a polar molecule . the oxygen here is more electronegative than this carbon , so we have a partial negative and we have a partial positive . this chlorine is also withdrawing electron density from our partially positive carbon , so we have a polar molecule . acetyl chloride is polar right here . this is polar . same molecule so this is polar . we have a partial negative , partial positive . once again this chloride is also withdrawing electron density this way . we have two polar molecules interacting which we know is a dipole dipole intermolecular force . there 's an attractive force between these molecules which is dipole dipole . let me go ahead and write that . it 's a dipole dipole interaction with molecules of actyl chloride . we know that dipole dipole interactions are stronger than london dispersion forces , so acetyl chloride has a higher boiling point than say a two carbon alkane , like ethane . it 's a little bit harder to pull these molecules apart than it is to pull molecules of ethane apart , therefore this boiling point is higher than that for a two carbon alkane . however this boiling point is lower than that of acetic acid . to think about that we 'll need to draw in another molecule of acetic acid . let me go ahead and do that . drawing in another molecule of acetic acid . we can see that there 's opportunities for hydrogen bonding . there 's a hydrogen bond here , and a hydrogen bond here . hydrogen bonding , go ahead and write that . hydrogen bonding is the strongest type of intermolecular force . therefore the boiling point of acetic acid is going to be higher , it 's somewhere around 118 degrees celsius . it 's harder to pull these two molecules apart because hydrogen bonding is a stronger intermolecular force than dipole dipole . that gives you some idea of the boiling point of acyl halides . in terms of solubility in water you ca n't really say that something like acetyl chloride is soluble in water because it reacts so violently with it . acetyl chloride is extremely reactive and it reacts very quickly and often violently with water , so we ca n't really say that it dissolves in water . let 's move on to acid anhydrides . let 's look at how to name an acid anhydride . acid anhydrides can be thought of as being derived from carboxylic acids too . if we look over here in the left once again we have acetic acid here , this is acetic acid . if we take two molecules of acetic acid and combine them we can form an acid anhydride . let 's think about what happens . we 're going to lose water here and the word anhydride means without water . if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names . you keep the acetic part and drop the acid , and just add anhydride . this is acetic anhydride . if you thought of acetic acid as ethanoic acid , if you prefer to use the iupac name , ethanoic acid . let me write ethanoic acid here . once again just drop the acid part and add anhydride . you could call this ethanoic anhydride . ethanoic anhydride . once again anhydride meaning without water . let 's look at how to name another anhydride . let me go down here and get some more room . we 're trying to name this anhydride over here on the right . to do that we need to think about the carboxylic acid , from which it can be thought of as being derived . here we have two molecules of benzoic acid . let 's go ahead and write benzoic acid here . i 'm not talking about exact chemical reactions , i 'm just thinking about the acid anhydride and how to put it into the different carboxylic acids . if we do the same thing we did before , we think about the term anhydride being loss of water , we take out water here and stick those together , once again you can see we form the anhydride on the right . this portion plus this portion gives us our acid anhydride . once again we 're not doing exact chemical reactions here . just for the sake of nomenclature we can just drop the acid and add anhydride . this would be benzoic anhydride . this would be benzoic anhydride , like that . let 's look at another example . this time we do n't have symmetry . when i 'm thinking about some carboxylic acids for this one , over here on the left i recognize benzoic acid . let me go ahead and write that down . benzoic acid is being present . if i think about over on the right side , this portion , if i think about a carboxylic acid this way i see that 's acetic acid . i have benzoic acid and acetic acid . to name our anhydride we drop the acid part and we 're going to add anhydride . we have to think about using the alphabet here . a comes before b , so to write the name of our anhydride we would write acetic benzoic anhydride . acetic benzoic anhydride . once again when you see an anhydride and you 're trying to name it just think about the carboxylic acids and that will help you figure out the name . in terms of physical properties of acid anhydrides let 's look at an example here . over here on the left we have acetic anhydride , which is a polar molecule . it 's moderately polar because we have these carbonyls here . the oxygen is partially negative , this carbon down here is partially positive , the same thing for all these carbonyls . it 's a moderately polar molecule . that 's a negative sign right there . there 's going to be some attraction between these molecules . there 's going to be some attraction between the negative and the positive charges . we have a fairly polar molecule and a fairly polar molecule , so we can say that there 's some dipole dipole interaction present . between molecules of acetic anhydride there 's some dipole dipole interaction . there 's also of course london dispersion forces as well . the boiling point for acetic anhydride turns out to be approximately 140 degrees celsius . let 's go ahead and write that in here , so approximately 140 degrees celsius . we can compare that to a carboxylic acid that 's similar in terms of number of carbons and oxygens . for acetic anhydride we had one , two , three , four carbons . over here on the right this is butanoic acid . we have one , two , three , four carbons . then we have two oxygens for butanoic acid and we have three oxygens for acetic anhydride . they 're similar in terms of sizes , but when we think about comparing their boiling points , over here on the right butanoic acid has a boiling point of approximately 164 degrees celsius , it has a higher boiling point because once again there 's some hydrogen bonding present . there 's some hydrogen bonding present because we 're talking about a carboxylic acid here . and once again hydrogen bonding is a stronger intermolecular force than dipole dipole so it 's harder to pull apart molecules of butanoic acid , therefore it takes more energy , it takes a higher temperature to pull these molecules apart to turn them into a gas . once again , h-bonding is a stronger intermolecular force than dipole dipole . when we think about the solubility of an acid anhydride in water , once again it 's kind of difficult . something like acetic anhydride is going to react with the water . acetic anhydride is also fairly reactive . not quite as reactive as an acyl halide but it does react with water , so we ca n't really say that it dissolves very well in it . we 'll talk much more about the reactivity of these carboxylic acid derivatives in a later video .
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if we take off the water and take this portion , take this acyl group and this over here and stick them together , then we form our anhydride over here on the right . because our anhydride was formed from acetic acid we call this acetic anhydride . these are pretty simple names .
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on the reaction of acetyl chloride with acetic acid in the presence of pyridine , how acetic anhyride is formed ?
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so i 'm going to recursively define an arithmetic sequence . so we 're going to say that they ith term of the sequence is equal to the i minus oneth term of the sequence plus 11 . so each term is going to be 11 more than the term before it . now we have to establish a base case here , and so we 're going to say that the first term of our arithmetic sequence is going to be equal to four . so given this recursive definition of our arithmetic sequence right over here , what i challenge you to do is to find the sum of the first 650 terms of the sequence . let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out . all right , so how can we think about this ? well , in many videos we give our intuition for the sum of an arithmetic sequence , and we came up with a formula for evaluating a sum of an arithmetic sequence , which we call an arithmetic series , and that sum of the first n terms is going to be the first term plus the last term over two , so really the average of the first and last terms , times the number of terms we have . and this is only the case when it 's an arithmetic series where each term that we 're adding is a fixed amount larger or less than the term before it , or that we have a fixed difference . so what about this one right over here ? what is the first and the last term going to be , and what is our n ? well we know that n is 650 , we know that n is 650 , and we know what the first term is going to be . the first terms is going to be four . we need to figure out what the nth term is , or we need to figure out what the 650th term is going to be . let 's think about this a little bit . so this is going to be , if we 're taking the sum , it 's going to be four plus the next term , the second term , so if a sub two is going to be a sub one plus 11 . so it 's going to be four plus 11 , which is 15 . we 're going to add 11 , which is going to get us to 26 , and we 're going to keep adding 11 . now how many times are we going to add 11 ? well to get to the second term , we add 11 once . to get to the third term , we add 11 twice . so to get to the 650th term , so this is a sub 650 , a sub 650 , we 're going to have to add 11 , look , to get to the second term , we added 11 once , third term , add 11 twice . so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once . third term , you added 11 twice . fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 . and so now we can just evaluate this . so i 'll get the calculator out for that . so we have 7,143 plus four plus the first term plus four is equal to that . we 're going to divide by two . so divide by two gets us 3,573.5 . we 're going to multiply that times 650 . that 's how many terms we have . times 650 is equal to , that 's a pretty large number , is going to be equal to 2,322,775 . 2,322,775 . i already forgot it . i have trouble remembering things when i take it off my screen . all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it . it never hurts to practice the arithmetic .
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let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out .
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what is the difference between a series and a sequence ?
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so i 'm going to recursively define an arithmetic sequence . so we 're going to say that they ith term of the sequence is equal to the i minus oneth term of the sequence plus 11 . so each term is going to be 11 more than the term before it . now we have to establish a base case here , and so we 're going to say that the first term of our arithmetic sequence is going to be equal to four . so given this recursive definition of our arithmetic sequence right over here , what i challenge you to do is to find the sum of the first 650 terms of the sequence . let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out . all right , so how can we think about this ? well , in many videos we give our intuition for the sum of an arithmetic sequence , and we came up with a formula for evaluating a sum of an arithmetic sequence , which we call an arithmetic series , and that sum of the first n terms is going to be the first term plus the last term over two , so really the average of the first and last terms , times the number of terms we have . and this is only the case when it 's an arithmetic series where each term that we 're adding is a fixed amount larger or less than the term before it , or that we have a fixed difference . so what about this one right over here ? what is the first and the last term going to be , and what is our n ? well we know that n is 650 , we know that n is 650 , and we know what the first term is going to be . the first terms is going to be four . we need to figure out what the nth term is , or we need to figure out what the 650th term is going to be . let 's think about this a little bit . so this is going to be , if we 're taking the sum , it 's going to be four plus the next term , the second term , so if a sub two is going to be a sub one plus 11 . so it 's going to be four plus 11 , which is 15 . we 're going to add 11 , which is going to get us to 26 , and we 're going to keep adding 11 . now how many times are we going to add 11 ? well to get to the second term , we add 11 once . to get to the third term , we add 11 twice . so to get to the 650th term , so this is a sub 650 , a sub 650 , we 're going to have to add 11 , look , to get to the second term , we added 11 once , third term , add 11 twice . so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once . third term , you added 11 twice . fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 . and so now we can just evaluate this . so i 'll get the calculator out for that . so we have 7,143 plus four plus the first term plus four is equal to that . we 're going to divide by two . so divide by two gets us 3,573.5 . we 're going to multiply that times 650 . that 's how many terms we have . times 650 is equal to , that 's a pretty large number , is going to be equal to 2,322,775 . 2,322,775 . i already forgot it . i have trouble remembering things when i take it off my screen . all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it . it never hurts to practice the arithmetic .
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all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it .
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if sums of recursive formulas could be found with algebra , why do people make computer programs to calculate this ?
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so i 'm going to recursively define an arithmetic sequence . so we 're going to say that they ith term of the sequence is equal to the i minus oneth term of the sequence plus 11 . so each term is going to be 11 more than the term before it . now we have to establish a base case here , and so we 're going to say that the first term of our arithmetic sequence is going to be equal to four . so given this recursive definition of our arithmetic sequence right over here , what i challenge you to do is to find the sum of the first 650 terms of the sequence . let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out . all right , so how can we think about this ? well , in many videos we give our intuition for the sum of an arithmetic sequence , and we came up with a formula for evaluating a sum of an arithmetic sequence , which we call an arithmetic series , and that sum of the first n terms is going to be the first term plus the last term over two , so really the average of the first and last terms , times the number of terms we have . and this is only the case when it 's an arithmetic series where each term that we 're adding is a fixed amount larger or less than the term before it , or that we have a fixed difference . so what about this one right over here ? what is the first and the last term going to be , and what is our n ? well we know that n is 650 , we know that n is 650 , and we know what the first term is going to be . the first terms is going to be four . we need to figure out what the nth term is , or we need to figure out what the 650th term is going to be . let 's think about this a little bit . so this is going to be , if we 're taking the sum , it 's going to be four plus the next term , the second term , so if a sub two is going to be a sub one plus 11 . so it 's going to be four plus 11 , which is 15 . we 're going to add 11 , which is going to get us to 26 , and we 're going to keep adding 11 . now how many times are we going to add 11 ? well to get to the second term , we add 11 once . to get to the third term , we add 11 twice . so to get to the 650th term , so this is a sub 650 , a sub 650 , we 're going to have to add 11 , look , to get to the second term , we added 11 once , third term , add 11 twice . so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once . third term , you added 11 twice . fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 . and so now we can just evaluate this . so i 'll get the calculator out for that . so we have 7,143 plus four plus the first term plus four is equal to that . we 're going to divide by two . so divide by two gets us 3,573.5 . we 're going to multiply that times 650 . that 's how many terms we have . times 650 is equal to , that 's a pretty large number , is going to be equal to 2,322,775 . 2,322,775 . i already forgot it . i have trouble remembering things when i take it off my screen . all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it . it never hurts to practice the arithmetic .
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so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 .
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can we find the 650th term by using an= a + ( n-1 ) d , where a is the first term and d is the common difference ?
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so i 'm going to recursively define an arithmetic sequence . so we 're going to say that they ith term of the sequence is equal to the i minus oneth term of the sequence plus 11 . so each term is going to be 11 more than the term before it . now we have to establish a base case here , and so we 're going to say that the first term of our arithmetic sequence is going to be equal to four . so given this recursive definition of our arithmetic sequence right over here , what i challenge you to do is to find the sum of the first 650 terms of the sequence . let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out . all right , so how can we think about this ? well , in many videos we give our intuition for the sum of an arithmetic sequence , and we came up with a formula for evaluating a sum of an arithmetic sequence , which we call an arithmetic series , and that sum of the first n terms is going to be the first term plus the last term over two , so really the average of the first and last terms , times the number of terms we have . and this is only the case when it 's an arithmetic series where each term that we 're adding is a fixed amount larger or less than the term before it , or that we have a fixed difference . so what about this one right over here ? what is the first and the last term going to be , and what is our n ? well we know that n is 650 , we know that n is 650 , and we know what the first term is going to be . the first terms is going to be four . we need to figure out what the nth term is , or we need to figure out what the 650th term is going to be . let 's think about this a little bit . so this is going to be , if we 're taking the sum , it 's going to be four plus the next term , the second term , so if a sub two is going to be a sub one plus 11 . so it 's going to be four plus 11 , which is 15 . we 're going to add 11 , which is going to get us to 26 , and we 're going to keep adding 11 . now how many times are we going to add 11 ? well to get to the second term , we add 11 once . to get to the third term , we add 11 twice . so to get to the 650th term , so this is a sub 650 , a sub 650 , we 're going to have to add 11 , look , to get to the second term , we added 11 once , third term , add 11 twice . so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once . third term , you added 11 twice . fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 . and so now we can just evaluate this . so i 'll get the calculator out for that . so we have 7,143 plus four plus the first term plus four is equal to that . we 're going to divide by two . so divide by two gets us 3,573.5 . we 're going to multiply that times 650 . that 's how many terms we have . times 650 is equal to , that 's a pretty large number , is going to be equal to 2,322,775 . 2,322,775 . i already forgot it . i have trouble remembering things when i take it off my screen . all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it . it never hurts to practice the arithmetic .
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fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 .
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4+649 ( 11 ) my quation what is 11 and how and why he add it there ?
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so i 'm going to recursively define an arithmetic sequence . so we 're going to say that they ith term of the sequence is equal to the i minus oneth term of the sequence plus 11 . so each term is going to be 11 more than the term before it . now we have to establish a base case here , and so we 're going to say that the first term of our arithmetic sequence is going to be equal to four . so given this recursive definition of our arithmetic sequence right over here , what i challenge you to do is to find the sum of the first 650 terms of the sequence . let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out . all right , so how can we think about this ? well , in many videos we give our intuition for the sum of an arithmetic sequence , and we came up with a formula for evaluating a sum of an arithmetic sequence , which we call an arithmetic series , and that sum of the first n terms is going to be the first term plus the last term over two , so really the average of the first and last terms , times the number of terms we have . and this is only the case when it 's an arithmetic series where each term that we 're adding is a fixed amount larger or less than the term before it , or that we have a fixed difference . so what about this one right over here ? what is the first and the last term going to be , and what is our n ? well we know that n is 650 , we know that n is 650 , and we know what the first term is going to be . the first terms is going to be four . we need to figure out what the nth term is , or we need to figure out what the 650th term is going to be . let 's think about this a little bit . so this is going to be , if we 're taking the sum , it 's going to be four plus the next term , the second term , so if a sub two is going to be a sub one plus 11 . so it 's going to be four plus 11 , which is 15 . we 're going to add 11 , which is going to get us to 26 , and we 're going to keep adding 11 . now how many times are we going to add 11 ? well to get to the second term , we add 11 once . to get to the third term , we add 11 twice . so to get to the 650th term , so this is a sub 650 , a sub 650 , we 're going to have to add 11 , look , to get to the second term , we added 11 once , third term , add 11 twice . so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once . third term , you added 11 twice . fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 . and so now we can just evaluate this . so i 'll get the calculator out for that . so we have 7,143 plus four plus the first term plus four is equal to that . we 're going to divide by two . so divide by two gets us 3,573.5 . we 're going to multiply that times 650 . that 's how many terms we have . times 650 is equal to , that 's a pretty large number , is going to be equal to 2,322,775 . 2,322,775 . i already forgot it . i have trouble remembering things when i take it off my screen . all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it . it never hurts to practice the arithmetic .
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so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once .
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i 'm confused , when do we add one to the `` n '' and when subtract and when take it as it is ?
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so i 'm going to recursively define an arithmetic sequence . so we 're going to say that they ith term of the sequence is equal to the i minus oneth term of the sequence plus 11 . so each term is going to be 11 more than the term before it . now we have to establish a base case here , and so we 're going to say that the first term of our arithmetic sequence is going to be equal to four . so given this recursive definition of our arithmetic sequence right over here , what i challenge you to do is to find the sum of the first 650 terms of the sequence . let me write that down . find the sum of first 650 terms of the sequence , of this arithmetic sequence that we have just defined . and like always , pause the video and see if you can work that out . all right , so how can we think about this ? well , in many videos we give our intuition for the sum of an arithmetic sequence , and we came up with a formula for evaluating a sum of an arithmetic sequence , which we call an arithmetic series , and that sum of the first n terms is going to be the first term plus the last term over two , so really the average of the first and last terms , times the number of terms we have . and this is only the case when it 's an arithmetic series where each term that we 're adding is a fixed amount larger or less than the term before it , or that we have a fixed difference . so what about this one right over here ? what is the first and the last term going to be , and what is our n ? well we know that n is 650 , we know that n is 650 , and we know what the first term is going to be . the first terms is going to be four . we need to figure out what the nth term is , or we need to figure out what the 650th term is going to be . let 's think about this a little bit . so this is going to be , if we 're taking the sum , it 's going to be four plus the next term , the second term , so if a sub two is going to be a sub one plus 11 . so it 's going to be four plus 11 , which is 15 . we 're going to add 11 , which is going to get us to 26 , and we 're going to keep adding 11 . now how many times are we going to add 11 ? well to get to the second term , we add 11 once . to get to the third term , we add 11 twice . so to get to the 650th term , so this is a sub 650 , a sub 650 , we 're going to have to add 11 , look , to get to the second term , we added 11 once , third term , add 11 twice . so to get to the 650th term , we are going to add 11 , we are going to add 11 650 minus one times , or 649 times . notice , to get to each term , to get to the first term , you added one minus one , you had an 11 one minus one times , you added 11 zero times . you started with the four , did n't add 11 at all . then the second term , you added 11 once . third term , you added 11 twice . fourth term , you added 11 three times . 650th term , you added 11 649 times . and so if you add 11 649 times , what do you get ? so four plus 649 times 11 is going to be equal to , i 'll get my calculator out for this , so this is going to be equal to 649 times 11 is equal to , now plus four is equal to 7,143 , 7,143 . so that 's the 650th term . 7 , 143 . and so now we can just evaluate this . so i 'll get the calculator out for that . so we have 7,143 plus four plus the first term plus four is equal to that . we 're going to divide by two . so divide by two gets us 3,573.5 . we 're going to multiply that times 650 . that 's how many terms we have . times 650 is equal to , that 's a pretty large number , is going to be equal to 2,322,775 . 2,322,775 . i already forgot it . i have trouble remembering things when i take it off my screen . all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it . it never hurts to practice the arithmetic .
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all right , 2,322,775 . i 'm glad i had a calculator in hand for that one , but you could do it by hand . i always encourage you to do it .
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if sums of recursive formulas could be found with algebra , why do people make computer programs to calculate this ?
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before . we talked about the heart rate in beats per minute , and we talked about the heartbeat itself -- the length of the heartbeat , and we 'd measured the heartbeat in terms of seconds . and you remember , there 's a nice little relationship between the two of these , because if the heartbeat actually gets shorter , then you can have more heart beats in a minute . and so of course , then the heart rate goes up . so that 's a relationship that explains how it is that our heart rate goes up and down . and we talked about the sa node , the av node , and the bundle of his . and we said starting with the sa node , the heart rate was somewhere between 60 and 90 . and i think i 'd chosen 90 , just because that was a nice , easy number to do math with . and we had said that the heart beat is about 0.66 seconds . so that 's the length of a heartbeat there . and then we have the av node . i 'm just going to quickly go through this . i know this is recap for you if you 've seen the other video . if you have n't , then these numbers come from basically dividing beats per minute down into seconds . and so then each beat then would be one second for the av node . and finally , we did the bundle of his . and i think i 've started trying to take a shortcut in writing bundle of his into just boh . and that looks something like this . and those underlying numbers are the numbers i 'm using to calculate the heartbeat lengths . so that 's basically what we had come up with . and we had also talked about the idea of having delays . you actually need time for the pulse to be in transit basically . and so , i 'm actually going to add a third column to our little table here . and there really is no delay here , because the sa node is where things are starting . so let me actually just keep my colors the same . and then the av node , we know that there 's a small delay , because things do move pretty quick . so we said that here , it 'd be something like 0.04 seconds . so you can see that it 's actually pretty quick getting from the sa node to the av node . but then it gets even faster as you get down to the bundle of his . it actually takes only about 0.005 seconds . so it gets really , really fast . and remember that this transit speed , this is really related to conduction velocity . so how fast is the signal getting conducted ? so we call this conduction velocity . and the relationship between conduction velocity and the action potential is the slope of phase 0 . remember , the more steep phase 0 is , the faster something is going to go from cell to cell to cell . and actually , that brings up a good point , because in the av node , there 's a huge delay built in , because the conduction is so darn slow . and so you have to actually remember that there 's this 0.1 second delay . and generally speaking , i think of 0.1 seconds as almost nothing , but when you compare it to 0.005 seconds , because that 's the transit time -- that 's how long it takes the signal to get down , we said from the av node down to our particular bundle of his cell -- then all of a sudden , this delay is looking enormous . by comparison , this looks like a really big , big number . and let me just write transit here as well . so this is time for movement . and then the delay is simply getting through the av node itself . so this is all just rehashing what we 've talked about before . and finally , just to get at least a drawing down , because i like to draw , we have our sa node here . and we have our av node here . and we have our bundle of his over here . and let me draw it half the distance , somewhere like this . and remember , this is the direction of flow . we 're basically trying to move this way . and again , this way . so let me actually jump into something slightly new . so let 's assume for a second -- this is a thought experiment -- that instead of 0.04 seconds , i 'm just going to focus on these two right now . instead of 0.04 seconds , let 's say that it took 100 times as long . for some reason , let 's say that transit time for some reason , we do n't know why , let 's say it takes 100 times longer . so this ends up being 4 seconds , right ? 0.04 times 100 is 4 seconds . so let 's say it takes about 4 seconds , for some reason , to get a signal from the sa node to the av node . well , what would that mean for us ? what would that look like exactly ? and i think you 'll start seeing some interesting lessons from this little thought experiment . so , if that was the case , if it was actually taking about 4 seconds to get from one point to another , let 's now draw out a timeline . this is a little time line , and this timeline starts at 0 seconds . and then you have , let 's say , 1 second here , 2 seconds , 3 -- i 'm just going to see how far this goes -- 4 , 5 , and let 's go to 6 . so , this is 6 . seconds and we 're going to follow what happens over 6 seconds . so let 's imagine now we keep track of our sa node up here . and we 're going to keep track of our av node down here . so at time 0 , let 's imagine that everything is beginning . and we watch our sa node , let 's start with that one first . well , at 2/3 of a second -- because that 's about how long it takes , we calculated -- we would get our first action potential , or a heart beat would go through , right ? first beat . and that would then try to make its way towards the av node . so this one is going to try to make its way towards the av node . but we know it takes 4 seconds to get there . now , what happens after that ? well , you 'd have another beat let off . the first one has n't actually made it to the av node , but the second one is already done by that point . and you 'd have a third beat that goes through by that point . and so really , we 're counting these action potentials that are going through the sa node . and they just keep going through . they 're just going to keep flowing through here . and they 're going to all just continue and basically , just what are we going to get ? a total of probably 9 , right ? we 're going to get 9 signals sent off . now , take each of them is going to take 4 seconds to get to the av node . so when will this first one get to the av node ? this very first one will get to the av node somewhere around here , because that 's 4 and 2/3 of a second . so at 4 and 2/3 of a second , this one -- let me somehow show you without making this too messy -- will make it to the av node right here . of course at that time , the sa node itself is letting out its seventh action potential , but that very first one will get there at that point . now the av node , is it going to sit around and wait for 4 and 2/3 of a second to just go by and not do anything ? no way , right ? there 's no way , because what it 's going to do is it 's going to say well , let 's wait for a signal from the sa node . and at this point , it 's going to say well , nothing arrived from the sa node , so i 'm going to let off my own signal . and it 's going to keep doing this . so it 's going to go on its own rhythm now . so 2 , 3 , so all this time , the av node is on its own rhythm . and then finally , before av node is able to fire off its own fifth action potential by itself , a signal arrives from the sa node , this red arrow that i drew in . and so it 'll say , oh wait . we just got some positive ion passed through the electrical conduction system . so let 's go with it . so it 'll have a signal there . and then now , it 'll have another one here , because what happens at that point ? well , you have this guy arrives . he took 4 seconds , and he arrives right there . and then this guy is going to arrive after that . he 's going to arrives right there . so you see they start arriving . and so , once they start arriving , then you get back onto what looks like a normal rhythm . and so , it 's interesting because you basically , as a result of this long delay , have a phenomenon where for awhile , the av node is doing its own thing over here . and then after that , the sa node catches up . and then it continues on what would look like a normal sinus rhythm . and so , sometimes you 'll hear the term escape beats or escape rhythm . and so that 's what these are , these are escape beats , meaning they have escaped the normal flow of electrical conduction , which starts with the sa node . so , hope that was helpful .
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and then it continues on what would look like a normal sinus rhythm . and so , sometimes you 'll hear the term escape beats or escape rhythm . and so that 's what these are , these are escape beats , meaning they have escaped the normal flow of electrical conduction , which starts with the sa node . so , hope that was helpful .
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are escaped beats the same as ectopic beats ?
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before . we talked about the heart rate in beats per minute , and we talked about the heartbeat itself -- the length of the heartbeat , and we 'd measured the heartbeat in terms of seconds . and you remember , there 's a nice little relationship between the two of these , because if the heartbeat actually gets shorter , then you can have more heart beats in a minute . and so of course , then the heart rate goes up . so that 's a relationship that explains how it is that our heart rate goes up and down . and we talked about the sa node , the av node , and the bundle of his . and we said starting with the sa node , the heart rate was somewhere between 60 and 90 . and i think i 'd chosen 90 , just because that was a nice , easy number to do math with . and we had said that the heart beat is about 0.66 seconds . so that 's the length of a heartbeat there . and then we have the av node . i 'm just going to quickly go through this . i know this is recap for you if you 've seen the other video . if you have n't , then these numbers come from basically dividing beats per minute down into seconds . and so then each beat then would be one second for the av node . and finally , we did the bundle of his . and i think i 've started trying to take a shortcut in writing bundle of his into just boh . and that looks something like this . and those underlying numbers are the numbers i 'm using to calculate the heartbeat lengths . so that 's basically what we had come up with . and we had also talked about the idea of having delays . you actually need time for the pulse to be in transit basically . and so , i 'm actually going to add a third column to our little table here . and there really is no delay here , because the sa node is where things are starting . so let me actually just keep my colors the same . and then the av node , we know that there 's a small delay , because things do move pretty quick . so we said that here , it 'd be something like 0.04 seconds . so you can see that it 's actually pretty quick getting from the sa node to the av node . but then it gets even faster as you get down to the bundle of his . it actually takes only about 0.005 seconds . so it gets really , really fast . and remember that this transit speed , this is really related to conduction velocity . so how fast is the signal getting conducted ? so we call this conduction velocity . and the relationship between conduction velocity and the action potential is the slope of phase 0 . remember , the more steep phase 0 is , the faster something is going to go from cell to cell to cell . and actually , that brings up a good point , because in the av node , there 's a huge delay built in , because the conduction is so darn slow . and so you have to actually remember that there 's this 0.1 second delay . and generally speaking , i think of 0.1 seconds as almost nothing , but when you compare it to 0.005 seconds , because that 's the transit time -- that 's how long it takes the signal to get down , we said from the av node down to our particular bundle of his cell -- then all of a sudden , this delay is looking enormous . by comparison , this looks like a really big , big number . and let me just write transit here as well . so this is time for movement . and then the delay is simply getting through the av node itself . so this is all just rehashing what we 've talked about before . and finally , just to get at least a drawing down , because i like to draw , we have our sa node here . and we have our av node here . and we have our bundle of his over here . and let me draw it half the distance , somewhere like this . and remember , this is the direction of flow . we 're basically trying to move this way . and again , this way . so let me actually jump into something slightly new . so let 's assume for a second -- this is a thought experiment -- that instead of 0.04 seconds , i 'm just going to focus on these two right now . instead of 0.04 seconds , let 's say that it took 100 times as long . for some reason , let 's say that transit time for some reason , we do n't know why , let 's say it takes 100 times longer . so this ends up being 4 seconds , right ? 0.04 times 100 is 4 seconds . so let 's say it takes about 4 seconds , for some reason , to get a signal from the sa node to the av node . well , what would that mean for us ? what would that look like exactly ? and i think you 'll start seeing some interesting lessons from this little thought experiment . so , if that was the case , if it was actually taking about 4 seconds to get from one point to another , let 's now draw out a timeline . this is a little time line , and this timeline starts at 0 seconds . and then you have , let 's say , 1 second here , 2 seconds , 3 -- i 'm just going to see how far this goes -- 4 , 5 , and let 's go to 6 . so , this is 6 . seconds and we 're going to follow what happens over 6 seconds . so let 's imagine now we keep track of our sa node up here . and we 're going to keep track of our av node down here . so at time 0 , let 's imagine that everything is beginning . and we watch our sa node , let 's start with that one first . well , at 2/3 of a second -- because that 's about how long it takes , we calculated -- we would get our first action potential , or a heart beat would go through , right ? first beat . and that would then try to make its way towards the av node . so this one is going to try to make its way towards the av node . but we know it takes 4 seconds to get there . now , what happens after that ? well , you 'd have another beat let off . the first one has n't actually made it to the av node , but the second one is already done by that point . and you 'd have a third beat that goes through by that point . and so really , we 're counting these action potentials that are going through the sa node . and they just keep going through . they 're just going to keep flowing through here . and they 're going to all just continue and basically , just what are we going to get ? a total of probably 9 , right ? we 're going to get 9 signals sent off . now , take each of them is going to take 4 seconds to get to the av node . so when will this first one get to the av node ? this very first one will get to the av node somewhere around here , because that 's 4 and 2/3 of a second . so at 4 and 2/3 of a second , this one -- let me somehow show you without making this too messy -- will make it to the av node right here . of course at that time , the sa node itself is letting out its seventh action potential , but that very first one will get there at that point . now the av node , is it going to sit around and wait for 4 and 2/3 of a second to just go by and not do anything ? no way , right ? there 's no way , because what it 's going to do is it 's going to say well , let 's wait for a signal from the sa node . and at this point , it 's going to say well , nothing arrived from the sa node , so i 'm going to let off my own signal . and it 's going to keep doing this . so it 's going to go on its own rhythm now . so 2 , 3 , so all this time , the av node is on its own rhythm . and then finally , before av node is able to fire off its own fifth action potential by itself , a signal arrives from the sa node , this red arrow that i drew in . and so it 'll say , oh wait . we just got some positive ion passed through the electrical conduction system . so let 's go with it . so it 'll have a signal there . and then now , it 'll have another one here , because what happens at that point ? well , you have this guy arrives . he took 4 seconds , and he arrives right there . and then this guy is going to arrive after that . he 's going to arrives right there . so you see they start arriving . and so , once they start arriving , then you get back onto what looks like a normal rhythm . and so , it 's interesting because you basically , as a result of this long delay , have a phenomenon where for awhile , the av node is doing its own thing over here . and then after that , the sa node catches up . and then it continues on what would look like a normal sinus rhythm . and so , sometimes you 'll hear the term escape beats or escape rhythm . and so that 's what these are , these are escape beats , meaning they have escaped the normal flow of electrical conduction , which starts with the sa node . so , hope that was helpful .
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before .
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what is a `` murmur '' ' , or `` slight murmur '' ?
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before . we talked about the heart rate in beats per minute , and we talked about the heartbeat itself -- the length of the heartbeat , and we 'd measured the heartbeat in terms of seconds . and you remember , there 's a nice little relationship between the two of these , because if the heartbeat actually gets shorter , then you can have more heart beats in a minute . and so of course , then the heart rate goes up . so that 's a relationship that explains how it is that our heart rate goes up and down . and we talked about the sa node , the av node , and the bundle of his . and we said starting with the sa node , the heart rate was somewhere between 60 and 90 . and i think i 'd chosen 90 , just because that was a nice , easy number to do math with . and we had said that the heart beat is about 0.66 seconds . so that 's the length of a heartbeat there . and then we have the av node . i 'm just going to quickly go through this . i know this is recap for you if you 've seen the other video . if you have n't , then these numbers come from basically dividing beats per minute down into seconds . and so then each beat then would be one second for the av node . and finally , we did the bundle of his . and i think i 've started trying to take a shortcut in writing bundle of his into just boh . and that looks something like this . and those underlying numbers are the numbers i 'm using to calculate the heartbeat lengths . so that 's basically what we had come up with . and we had also talked about the idea of having delays . you actually need time for the pulse to be in transit basically . and so , i 'm actually going to add a third column to our little table here . and there really is no delay here , because the sa node is where things are starting . so let me actually just keep my colors the same . and then the av node , we know that there 's a small delay , because things do move pretty quick . so we said that here , it 'd be something like 0.04 seconds . so you can see that it 's actually pretty quick getting from the sa node to the av node . but then it gets even faster as you get down to the bundle of his . it actually takes only about 0.005 seconds . so it gets really , really fast . and remember that this transit speed , this is really related to conduction velocity . so how fast is the signal getting conducted ? so we call this conduction velocity . and the relationship between conduction velocity and the action potential is the slope of phase 0 . remember , the more steep phase 0 is , the faster something is going to go from cell to cell to cell . and actually , that brings up a good point , because in the av node , there 's a huge delay built in , because the conduction is so darn slow . and so you have to actually remember that there 's this 0.1 second delay . and generally speaking , i think of 0.1 seconds as almost nothing , but when you compare it to 0.005 seconds , because that 's the transit time -- that 's how long it takes the signal to get down , we said from the av node down to our particular bundle of his cell -- then all of a sudden , this delay is looking enormous . by comparison , this looks like a really big , big number . and let me just write transit here as well . so this is time for movement . and then the delay is simply getting through the av node itself . so this is all just rehashing what we 've talked about before . and finally , just to get at least a drawing down , because i like to draw , we have our sa node here . and we have our av node here . and we have our bundle of his over here . and let me draw it half the distance , somewhere like this . and remember , this is the direction of flow . we 're basically trying to move this way . and again , this way . so let me actually jump into something slightly new . so let 's assume for a second -- this is a thought experiment -- that instead of 0.04 seconds , i 'm just going to focus on these two right now . instead of 0.04 seconds , let 's say that it took 100 times as long . for some reason , let 's say that transit time for some reason , we do n't know why , let 's say it takes 100 times longer . so this ends up being 4 seconds , right ? 0.04 times 100 is 4 seconds . so let 's say it takes about 4 seconds , for some reason , to get a signal from the sa node to the av node . well , what would that mean for us ? what would that look like exactly ? and i think you 'll start seeing some interesting lessons from this little thought experiment . so , if that was the case , if it was actually taking about 4 seconds to get from one point to another , let 's now draw out a timeline . this is a little time line , and this timeline starts at 0 seconds . and then you have , let 's say , 1 second here , 2 seconds , 3 -- i 'm just going to see how far this goes -- 4 , 5 , and let 's go to 6 . so , this is 6 . seconds and we 're going to follow what happens over 6 seconds . so let 's imagine now we keep track of our sa node up here . and we 're going to keep track of our av node down here . so at time 0 , let 's imagine that everything is beginning . and we watch our sa node , let 's start with that one first . well , at 2/3 of a second -- because that 's about how long it takes , we calculated -- we would get our first action potential , or a heart beat would go through , right ? first beat . and that would then try to make its way towards the av node . so this one is going to try to make its way towards the av node . but we know it takes 4 seconds to get there . now , what happens after that ? well , you 'd have another beat let off . the first one has n't actually made it to the av node , but the second one is already done by that point . and you 'd have a third beat that goes through by that point . and so really , we 're counting these action potentials that are going through the sa node . and they just keep going through . they 're just going to keep flowing through here . and they 're going to all just continue and basically , just what are we going to get ? a total of probably 9 , right ? we 're going to get 9 signals sent off . now , take each of them is going to take 4 seconds to get to the av node . so when will this first one get to the av node ? this very first one will get to the av node somewhere around here , because that 's 4 and 2/3 of a second . so at 4 and 2/3 of a second , this one -- let me somehow show you without making this too messy -- will make it to the av node right here . of course at that time , the sa node itself is letting out its seventh action potential , but that very first one will get there at that point . now the av node , is it going to sit around and wait for 4 and 2/3 of a second to just go by and not do anything ? no way , right ? there 's no way , because what it 's going to do is it 's going to say well , let 's wait for a signal from the sa node . and at this point , it 's going to say well , nothing arrived from the sa node , so i 'm going to let off my own signal . and it 's going to keep doing this . so it 's going to go on its own rhythm now . so 2 , 3 , so all this time , the av node is on its own rhythm . and then finally , before av node is able to fire off its own fifth action potential by itself , a signal arrives from the sa node , this red arrow that i drew in . and so it 'll say , oh wait . we just got some positive ion passed through the electrical conduction system . so let 's go with it . so it 'll have a signal there . and then now , it 'll have another one here , because what happens at that point ? well , you have this guy arrives . he took 4 seconds , and he arrives right there . and then this guy is going to arrive after that . he 's going to arrives right there . so you see they start arriving . and so , once they start arriving , then you get back onto what looks like a normal rhythm . and so , it 's interesting because you basically , as a result of this long delay , have a phenomenon where for awhile , the av node is doing its own thing over here . and then after that , the sa node catches up . and then it continues on what would look like a normal sinus rhythm . and so , sometimes you 'll hear the term escape beats or escape rhythm . and so that 's what these are , these are escape beats , meaning they have escaped the normal flow of electrical conduction , which starts with the sa node . so , hope that was helpful .
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so we call this conduction velocity . and the relationship between conduction velocity and the action potential is the slope of phase 0 . remember , the more steep phase 0 is , the faster something is going to go from cell to cell to cell .
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did you mean the slope of phase 4 , as that is where they differ in na+ permeability ?
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before . we talked about the heart rate in beats per minute , and we talked about the heartbeat itself -- the length of the heartbeat , and we 'd measured the heartbeat in terms of seconds . and you remember , there 's a nice little relationship between the two of these , because if the heartbeat actually gets shorter , then you can have more heart beats in a minute . and so of course , then the heart rate goes up . so that 's a relationship that explains how it is that our heart rate goes up and down . and we talked about the sa node , the av node , and the bundle of his . and we said starting with the sa node , the heart rate was somewhere between 60 and 90 . and i think i 'd chosen 90 , just because that was a nice , easy number to do math with . and we had said that the heart beat is about 0.66 seconds . so that 's the length of a heartbeat there . and then we have the av node . i 'm just going to quickly go through this . i know this is recap for you if you 've seen the other video . if you have n't , then these numbers come from basically dividing beats per minute down into seconds . and so then each beat then would be one second for the av node . and finally , we did the bundle of his . and i think i 've started trying to take a shortcut in writing bundle of his into just boh . and that looks something like this . and those underlying numbers are the numbers i 'm using to calculate the heartbeat lengths . so that 's basically what we had come up with . and we had also talked about the idea of having delays . you actually need time for the pulse to be in transit basically . and so , i 'm actually going to add a third column to our little table here . and there really is no delay here , because the sa node is where things are starting . so let me actually just keep my colors the same . and then the av node , we know that there 's a small delay , because things do move pretty quick . so we said that here , it 'd be something like 0.04 seconds . so you can see that it 's actually pretty quick getting from the sa node to the av node . but then it gets even faster as you get down to the bundle of his . it actually takes only about 0.005 seconds . so it gets really , really fast . and remember that this transit speed , this is really related to conduction velocity . so how fast is the signal getting conducted ? so we call this conduction velocity . and the relationship between conduction velocity and the action potential is the slope of phase 0 . remember , the more steep phase 0 is , the faster something is going to go from cell to cell to cell . and actually , that brings up a good point , because in the av node , there 's a huge delay built in , because the conduction is so darn slow . and so you have to actually remember that there 's this 0.1 second delay . and generally speaking , i think of 0.1 seconds as almost nothing , but when you compare it to 0.005 seconds , because that 's the transit time -- that 's how long it takes the signal to get down , we said from the av node down to our particular bundle of his cell -- then all of a sudden , this delay is looking enormous . by comparison , this looks like a really big , big number . and let me just write transit here as well . so this is time for movement . and then the delay is simply getting through the av node itself . so this is all just rehashing what we 've talked about before . and finally , just to get at least a drawing down , because i like to draw , we have our sa node here . and we have our av node here . and we have our bundle of his over here . and let me draw it half the distance , somewhere like this . and remember , this is the direction of flow . we 're basically trying to move this way . and again , this way . so let me actually jump into something slightly new . so let 's assume for a second -- this is a thought experiment -- that instead of 0.04 seconds , i 'm just going to focus on these two right now . instead of 0.04 seconds , let 's say that it took 100 times as long . for some reason , let 's say that transit time for some reason , we do n't know why , let 's say it takes 100 times longer . so this ends up being 4 seconds , right ? 0.04 times 100 is 4 seconds . so let 's say it takes about 4 seconds , for some reason , to get a signal from the sa node to the av node . well , what would that mean for us ? what would that look like exactly ? and i think you 'll start seeing some interesting lessons from this little thought experiment . so , if that was the case , if it was actually taking about 4 seconds to get from one point to another , let 's now draw out a timeline . this is a little time line , and this timeline starts at 0 seconds . and then you have , let 's say , 1 second here , 2 seconds , 3 -- i 'm just going to see how far this goes -- 4 , 5 , and let 's go to 6 . so , this is 6 . seconds and we 're going to follow what happens over 6 seconds . so let 's imagine now we keep track of our sa node up here . and we 're going to keep track of our av node down here . so at time 0 , let 's imagine that everything is beginning . and we watch our sa node , let 's start with that one first . well , at 2/3 of a second -- because that 's about how long it takes , we calculated -- we would get our first action potential , or a heart beat would go through , right ? first beat . and that would then try to make its way towards the av node . so this one is going to try to make its way towards the av node . but we know it takes 4 seconds to get there . now , what happens after that ? well , you 'd have another beat let off . the first one has n't actually made it to the av node , but the second one is already done by that point . and you 'd have a third beat that goes through by that point . and so really , we 're counting these action potentials that are going through the sa node . and they just keep going through . they 're just going to keep flowing through here . and they 're going to all just continue and basically , just what are we going to get ? a total of probably 9 , right ? we 're going to get 9 signals sent off . now , take each of them is going to take 4 seconds to get to the av node . so when will this first one get to the av node ? this very first one will get to the av node somewhere around here , because that 's 4 and 2/3 of a second . so at 4 and 2/3 of a second , this one -- let me somehow show you without making this too messy -- will make it to the av node right here . of course at that time , the sa node itself is letting out its seventh action potential , but that very first one will get there at that point . now the av node , is it going to sit around and wait for 4 and 2/3 of a second to just go by and not do anything ? no way , right ? there 's no way , because what it 's going to do is it 's going to say well , let 's wait for a signal from the sa node . and at this point , it 's going to say well , nothing arrived from the sa node , so i 'm going to let off my own signal . and it 's going to keep doing this . so it 's going to go on its own rhythm now . so 2 , 3 , so all this time , the av node is on its own rhythm . and then finally , before av node is able to fire off its own fifth action potential by itself , a signal arrives from the sa node , this red arrow that i drew in . and so it 'll say , oh wait . we just got some positive ion passed through the electrical conduction system . so let 's go with it . so it 'll have a signal there . and then now , it 'll have another one here , because what happens at that point ? well , you have this guy arrives . he took 4 seconds , and he arrives right there . and then this guy is going to arrive after that . he 's going to arrives right there . so you see they start arriving . and so , once they start arriving , then you get back onto what looks like a normal rhythm . and so , it 's interesting because you basically , as a result of this long delay , have a phenomenon where for awhile , the av node is doing its own thing over here . and then after that , the sa node catches up . and then it continues on what would look like a normal sinus rhythm . and so , sometimes you 'll hear the term escape beats or escape rhythm . and so that 's what these are , these are escape beats , meaning they have escaped the normal flow of electrical conduction , which starts with the sa node . so , hope that was helpful .
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and actually , that brings up a good point , because in the av node , there 's a huge delay built in , because the conduction is so darn slow . and so you have to actually remember that there 's this 0.1 second delay . and generally speaking , i think of 0.1 seconds as almost nothing , but when you compare it to 0.005 seconds , because that 's the transit time -- that 's how long it takes the signal to get down , we said from the av node down to our particular bundle of his cell -- then all of a sudden , this delay is looking enormous .
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how is the 0.1 second delay in the av node accomplished ?
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before . we talked about the heart rate in beats per minute , and we talked about the heartbeat itself -- the length of the heartbeat , and we 'd measured the heartbeat in terms of seconds . and you remember , there 's a nice little relationship between the two of these , because if the heartbeat actually gets shorter , then you can have more heart beats in a minute . and so of course , then the heart rate goes up . so that 's a relationship that explains how it is that our heart rate goes up and down . and we talked about the sa node , the av node , and the bundle of his . and we said starting with the sa node , the heart rate was somewhere between 60 and 90 . and i think i 'd chosen 90 , just because that was a nice , easy number to do math with . and we had said that the heart beat is about 0.66 seconds . so that 's the length of a heartbeat there . and then we have the av node . i 'm just going to quickly go through this . i know this is recap for you if you 've seen the other video . if you have n't , then these numbers come from basically dividing beats per minute down into seconds . and so then each beat then would be one second for the av node . and finally , we did the bundle of his . and i think i 've started trying to take a shortcut in writing bundle of his into just boh . and that looks something like this . and those underlying numbers are the numbers i 'm using to calculate the heartbeat lengths . so that 's basically what we had come up with . and we had also talked about the idea of having delays . you actually need time for the pulse to be in transit basically . and so , i 'm actually going to add a third column to our little table here . and there really is no delay here , because the sa node is where things are starting . so let me actually just keep my colors the same . and then the av node , we know that there 's a small delay , because things do move pretty quick . so we said that here , it 'd be something like 0.04 seconds . so you can see that it 's actually pretty quick getting from the sa node to the av node . but then it gets even faster as you get down to the bundle of his . it actually takes only about 0.005 seconds . so it gets really , really fast . and remember that this transit speed , this is really related to conduction velocity . so how fast is the signal getting conducted ? so we call this conduction velocity . and the relationship between conduction velocity and the action potential is the slope of phase 0 . remember , the more steep phase 0 is , the faster something is going to go from cell to cell to cell . and actually , that brings up a good point , because in the av node , there 's a huge delay built in , because the conduction is so darn slow . and so you have to actually remember that there 's this 0.1 second delay . and generally speaking , i think of 0.1 seconds as almost nothing , but when you compare it to 0.005 seconds , because that 's the transit time -- that 's how long it takes the signal to get down , we said from the av node down to our particular bundle of his cell -- then all of a sudden , this delay is looking enormous . by comparison , this looks like a really big , big number . and let me just write transit here as well . so this is time for movement . and then the delay is simply getting through the av node itself . so this is all just rehashing what we 've talked about before . and finally , just to get at least a drawing down , because i like to draw , we have our sa node here . and we have our av node here . and we have our bundle of his over here . and let me draw it half the distance , somewhere like this . and remember , this is the direction of flow . we 're basically trying to move this way . and again , this way . so let me actually jump into something slightly new . so let 's assume for a second -- this is a thought experiment -- that instead of 0.04 seconds , i 'm just going to focus on these two right now . instead of 0.04 seconds , let 's say that it took 100 times as long . for some reason , let 's say that transit time for some reason , we do n't know why , let 's say it takes 100 times longer . so this ends up being 4 seconds , right ? 0.04 times 100 is 4 seconds . so let 's say it takes about 4 seconds , for some reason , to get a signal from the sa node to the av node . well , what would that mean for us ? what would that look like exactly ? and i think you 'll start seeing some interesting lessons from this little thought experiment . so , if that was the case , if it was actually taking about 4 seconds to get from one point to another , let 's now draw out a timeline . this is a little time line , and this timeline starts at 0 seconds . and then you have , let 's say , 1 second here , 2 seconds , 3 -- i 'm just going to see how far this goes -- 4 , 5 , and let 's go to 6 . so , this is 6 . seconds and we 're going to follow what happens over 6 seconds . so let 's imagine now we keep track of our sa node up here . and we 're going to keep track of our av node down here . so at time 0 , let 's imagine that everything is beginning . and we watch our sa node , let 's start with that one first . well , at 2/3 of a second -- because that 's about how long it takes , we calculated -- we would get our first action potential , or a heart beat would go through , right ? first beat . and that would then try to make its way towards the av node . so this one is going to try to make its way towards the av node . but we know it takes 4 seconds to get there . now , what happens after that ? well , you 'd have another beat let off . the first one has n't actually made it to the av node , but the second one is already done by that point . and you 'd have a third beat that goes through by that point . and so really , we 're counting these action potentials that are going through the sa node . and they just keep going through . they 're just going to keep flowing through here . and they 're going to all just continue and basically , just what are we going to get ? a total of probably 9 , right ? we 're going to get 9 signals sent off . now , take each of them is going to take 4 seconds to get to the av node . so when will this first one get to the av node ? this very first one will get to the av node somewhere around here , because that 's 4 and 2/3 of a second . so at 4 and 2/3 of a second , this one -- let me somehow show you without making this too messy -- will make it to the av node right here . of course at that time , the sa node itself is letting out its seventh action potential , but that very first one will get there at that point . now the av node , is it going to sit around and wait for 4 and 2/3 of a second to just go by and not do anything ? no way , right ? there 's no way , because what it 's going to do is it 's going to say well , let 's wait for a signal from the sa node . and at this point , it 's going to say well , nothing arrived from the sa node , so i 'm going to let off my own signal . and it 's going to keep doing this . so it 's going to go on its own rhythm now . so 2 , 3 , so all this time , the av node is on its own rhythm . and then finally , before av node is able to fire off its own fifth action potential by itself , a signal arrives from the sa node , this red arrow that i drew in . and so it 'll say , oh wait . we just got some positive ion passed through the electrical conduction system . so let 's go with it . so it 'll have a signal there . and then now , it 'll have another one here , because what happens at that point ? well , you have this guy arrives . he took 4 seconds , and he arrives right there . and then this guy is going to arrive after that . he 's going to arrives right there . so you see they start arriving . and so , once they start arriving , then you get back onto what looks like a normal rhythm . and so , it 's interesting because you basically , as a result of this long delay , have a phenomenon where for awhile , the av node is doing its own thing over here . and then after that , the sa node catches up . and then it continues on what would look like a normal sinus rhythm . and so , sometimes you 'll hear the term escape beats or escape rhythm . and so that 's what these are , these are escape beats , meaning they have escaped the normal flow of electrical conduction , which starts with the sa node . so , hope that was helpful .
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so i know we talked about different pacemakers in the body , but i thought it 'd be fun to revisit that and show you an interesting example . so let 's start out by laying out the table we 'd set up before .
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are there proportionately fewer gap junctions and so fewer avenues for ions to permeate into those nodal cells ?
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