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NDQ_018150 | electromagnetic waves vary in their wavelengths and frequencies. | a. true, b. false | a | Lesson: radio waves
A Spectrum of Waves:
Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of e... |
NDQ_018153 | radio waves have the highest frequencies of all electromagnetic waves. | a. true, b. false | b | Lesson: radio waves
A Spectrum of Waves:
Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of e... |
NDQ_018154 | radio waves have the least energy of all electromagnetic waves. | a. true, b. false | a | Lesson: radio waves
A Spectrum of Waves:
Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of e... |
NDQ_018155 | radio waves vary in frequency from | a. 105 to 1012 hz, b. 1050 to 10,120 hz, c. 10,500 to 101,200 hz, d. none of the above | a | Lesson: radio waves
A Spectrum of Waves:
Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of e... |
NDQ_018156 | am radio waves | a. have longer wavelengths than fm radio waves, b. are encoded with signals by changing their amplitude, c. reflect off the ionosphere, d. all of the above | d | Lesson: radio waves
A Spectrum of Waves:
Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of e... |
NDQ_018158 | in tv broadcasts | a. radio waves carry both sound and picture signals, b. sounds are encoded withy amplitude modulation, c. pictures are encoded with frequency modulation, d. all of the above | a | Lesson: radio waves
A Spectrum of Waves:
Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of e... |
NDQ_018163 | radioactive decay is a chemical reaction. | a. true, b. false | b | Lesson: radioactive decay
Introducing Radioactive Decay:
Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radi... |
NDQ_018164 | radioactive decay may change one element into another. | a. true, b. false | a | Lesson: radioactive decay
Introducing Radioactive Decay:
Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radi... |
NDQ_018165 | energy is emitted by a nucleus when it undergoes | a. alpha decay, b. beta decay, c. gamma decay, d. any of the above | d | Lesson: radioactive decay
Introducing Radioactive Decay:
Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radi... |
NDQ_018166 | the type of radioactive decay that occurs when a nucleus emits an electron is | a. alpha decay, b. beta decay, c. gamma decay, d. none of the above | b | Lesson: radioactive decay
Introducing Radioactive Decay:
Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radi... |
NDQ_018167 | the type of radioactive decay that occurs when a nucleus emits two protons and two neutrons is | a. alpha decay, b. beta decay, c. gamma decay, d. none of the above | a | Lesson: radioactive decay
Introducing Radioactive Decay:
Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radi... |
NDQ_018170 | certain chemical processes can change one element into another. | a. true, b. false | b | Lesson: radioactivity
Elements and Protons:
For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can on... |
NDQ_018171 | atoms of each element have a unique number of | a. protons, b. neutrons, c. isotopes, d. two of the above | a | Lesson: radioactivity
Elements and Protons:
For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can on... |
NDQ_018174 | all nuclei emit radiation. | a. true, b. false | b | Lesson: radioactivity
Elements and Protons:
For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can on... |
NDQ_018175 | nuclei may be unstable if they have | a. too much energy, b. too many protons, c. an unstable ratio of protons to neutrons, d. any of the above | d | Lesson: radioactivity
Elements and Protons:
For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can on... |
NDQ_018176 | all elements with more than 75 protons are unstable. | a. true, b. false | b | Lesson: radioactivity
Elements and Protons:
For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can on... |
NDQ_018177 | which of the following elements are radioactive? | a. uranium, b. radium, c. polonium, d. all of the above | d | Lesson: radioactivity
Elements and Protons:
For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can on... |
NDQ_018181 | only radioactive elements have isotopes that are radioactive. | a. true, b. false | b | Lesson: radioisotopes
What Are Radioisotopes:
All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactiv... |
NDQ_018183 | radioactive isotopes are unstable because they have too many electrons. | a. true, b. false | b | Lesson: radioisotopes
What Are Radioisotopes:
All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactiv... |
NDQ_018184 | the nucleus that is most likely to be unstable is the nucleus that has | a. 2 protons and 2 neutrons, b. 4 protons and 4 neutrons, c. 6 protons and 8 neutrons, d. 60 protons and 90 neutrons | c | Lesson: radioisotopes
What Are Radioisotopes:
All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactiv... |
NDQ_018185 | the radioisotope of carbon is called | a. carbon-6, b. carbon-8, c. carbon-13, d. carbon-14 | d | Lesson: radioisotopes
What Are Radioisotopes:
All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactiv... |
NDQ_018200 | chemical changes occur because of chemical reactions. | a. true, b. false | a | Lesson: reactants and products
From Reactants to Products:
All chemical reactionsincluding a candle burninginvolve reactants and products. Reactants are substances that start a chemical reaction. Products are substances that are produced in the reaction. When a candle burns, the reactants are fuel (the candlewick and ... |
NDQ_018201 | an example of a chemical change is a candle burning. | a. true, b. false | a | Lesson: reactants and products
From Reactants to Products:
All chemical reactionsincluding a candle burninginvolve reactants and products. Reactants are substances that start a chemical reaction. Products are substances that are produced in the reaction. When a candle burns, the reactants are fuel (the candlewick and ... |
NDQ_018202 | any substance that starts a chemical reaction is called a | a. reactor, b. regent, c. reactant, d. none of the above | c | Lesson: reactants and products
From Reactants to Products:
All chemical reactionsincluding a candle burninginvolve reactants and products. Reactants are substances that start a chemical reaction. Products are substances that are produced in the reaction. When a candle burns, the reactants are fuel (the candlewick and ... |
NDQ_018203 | any substance that results from a chemical reaction is called a | a. producer, b. product, c. productor, d. none of the above | b | Lesson: reactants and products
From Reactants to Products:
All chemical reactionsincluding a candle burninginvolve reactants and products. Reactants are substances that start a chemical reaction. Products are substances that are produced in the reaction. When a candle burns, the reactants are fuel (the candlewick and ... |
NDQ_018205 | products of a combustion reaction include | a. fuel, b. oxygen, c. water, d. two of the above | c | Lesson: reactants and products
From Reactants to Products:
All chemical reactionsincluding a candle burninginvolve reactants and products. Reactants are substances that start a chemical reaction. Products are substances that are produced in the reaction. When a candle burns, the reactants are fuel (the candlewick and ... |
NDQ_018210 | all changes in matter are the result of chemical reactions. | a. true, b. false | b | Lesson: recognizing chemical reactions
Whats Your Sign:
A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction... |
NDQ_018211 | signs that a chemical reaction has occurred include a change in | a. temperature, b. color, c. state, d. two of the above | d | Lesson: recognizing chemical reactions
Whats Your Sign:
A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction... |
NDQ_018215 | which of the following is a sign of a chemical reaction? | a. a liquid changes to a solid, b. a liquid changes to a gas, c. a solid changes to a gas, d. a gas is released from a liquid | d | Lesson: recognizing chemical reactions
Whats Your Sign:
A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction... |
NDQ_018216 | the solid lumps in cottage cheese are an example of a precipitate. | a. true, b. false | a | Lesson: recognizing chemical reactions
Whats Your Sign:
A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction... |
NDQ_018217 | the release of gas bubbles is a sign of a chemical reaction. | a. true, b. false | a | Lesson: recognizing chemical reactions
Whats Your Sign:
A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction... |
NDQ_018218 | which of the following does not involve chemical reactions? | a. leaves change color in the fall, b. a pond freezes over in the winter, c. a fire burns a pile of fallen leaves, d. fallen leaves decay in a compost pile | b | Lesson: recognizing chemical reactions
Whats Your Sign:
A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction... |
NDQ_018231 | less reactive elements replace more reactive elements in compounds. | a. true, b. false | b | Lesson: replacement reactions
What Is A Replacement Reaction:
A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal a... |
NDQ_018232 | replacement reactions always involve ionic compounds. | a. true, b. false | a | Lesson: replacement reactions
What Is A Replacement Reaction:
A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal a... |
NDQ_018233 | a single replacement reaction always involves two reactant compounds. | a. true, b. false | b | Lesson: replacement reactions
What Is A Replacement Reaction:
A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal a... |
NDQ_018234 | which of the following is a single replacement reaction? | a. fes + 2hcl h2s + fecl2, b. fe + cuso4 feso4 + cu, c. agno3 + nacl ---> agcl + nano3, d. none of the above | b | Lesson: replacement reactions
What Is A Replacement Reaction:
A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal a... |
NDQ_018235 | the general equation for a double replacement reaction is | a. ab + cd bc + da, b. ab + c + d ad + cb, c. ab + c ac + b, d. none of the above | d | Lesson: replacement reactions
What Is A Replacement Reaction:
A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal a... |
NDQ_018238 | a compound in a replacement reaction always consists of | a. a positive ion and a negative ion, b. a metal ion and a nonmetal ion, c. two negative metal ions, d. two of the above | d | Lesson: replacement reactions
What Is A Replacement Reaction:
A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal a... |
NDQ_018254 | in rutherfords experiments, most of the alpha particles | a. were deflected by the gold foil, b. passed straight through the gold foil, c. bounced straight back from the gold foil, d. none of the above | b | Lesson: rutherfords atomic model
Narrowing Down the Nucleus:
In 1804, almost a century before the nucleus was discovered, the English scientist John Dalton provided evidence for the existence of the atom. Dalton thought that atoms were the smallest particles of matter, which couldnt be divided into smaller particles. ... |
NDQ_018255 | from his results, rutherford concluded that the positive charge of an atom is | a. less than the negative charge of the atom, b. spread evenly throughout the atom, c. concentrated in a tiny area at the center of the atom, d. two of the above | c | Lesson: rutherfords atomic model
Narrowing Down the Nucleus:
In 1804, almost a century before the nucleus was discovered, the English scientist John Dalton provided evidence for the existence of the atom. Dalton thought that atoms were the smallest particles of matter, which couldnt be divided into smaller particles. ... |
NDQ_018256 | based on his research, rutherford thought that most of an atom consists of empty space. | a. true, b. false | a | Lesson: rutherfords atomic model
Narrowing Down the Nucleus:
In 1804, almost a century before the nucleus was discovered, the English scientist John Dalton provided evidence for the existence of the atom. Dalton thought that atoms were the smallest particles of matter, which couldnt be divided into smaller particles. ... |
NDQ_018257 | rutherford predicted the existence of neutrons but failed to find them. | a. true, b. false | a | Lesson: rutherfords atomic model
Narrowing Down the Nucleus:
In 1804, almost a century before the nucleus was discovered, the English scientist John Dalton provided evidence for the existence of the atom. Dalton thought that atoms were the smallest particles of matter, which couldnt be divided into smaller particles. ... |
NDQ_018272 | the melting points of saturated hydrocarbons are determined mainly by their number of | a. double bonds, b. hydrogen atoms, c. carbon atoms, d. none of the above | c | Lesson: saturated hydrocarbons
What Are Saturated Hydrocarbons:
Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, t... |
NDQ_018273 | which saturated hydrocarbon has the chemical formula c2h6? | a. methane, b. ethane, c. propane, d. butane | b | Lesson: saturated hydrocarbons
What Are Saturated Hydrocarbons:
Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, t... |
NDQ_018274 | which saturated hydrocarbon has eight carbon atoms? | a. pentane, b. hexane, c. heptane, d. octane | d | Lesson: saturated hydrocarbons
What Are Saturated Hydrocarbons:
Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, t... |
NDQ_018275 | methane has a higher boiling point than ethane. | a. true, b. false | b | Lesson: saturated hydrocarbons
What Are Saturated Hydrocarbons:
Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, t... |
NDQ_018276 | some alkanes are solids are room temperature. | a. true, b. false | a | Lesson: saturated hydrocarbons
What Are Saturated Hydrocarbons:
Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, t... |
NDQ_018300 | types of graphs include | a. bar graphs, b. line graphs, c. circle graphs, d. all of the above | d | Lesson: scientific graphing
Using Graphs in Science:
Graphs are very useful tools in science. They can help you visualize a set of data. With a graph, you can actually see what all the numbers in a data table mean. Three commonly used types of graphs are bar graphs, circle graphs, and line graphs. Each type of graph i... |
NDQ_018301 | different types of graph are best suited for representing different types of data. | a. true, b. false | a | Lesson: scientific graphing
Using Graphs in Science:
Graphs are very useful tools in science. They can help you visualize a set of data. With a graph, you can actually see what all the numbers in a data table mean. Three commonly used types of graphs are bar graphs, circle graphs, and line graphs. Each type of graph i... |
NDQ_018342 | to be useful, a scientific model must | a. closely represent the real thing in important ways, b. be simpler than the real thing, c. be easier to understand than the real thing, d. all of the above | d | Lesson: scientific modeling
What Is a Model:
A model is a representation of an object, system, or process. For example, a road map is a representation of an actual system of roads on the ground. Models are very useful in science. They provide a way to investigate things that are too small, large, complex, or distant t... |
NDQ_018346 | a chemical equation is an example of a model. | a. true, b. false | a | Lesson: scientific modeling
What Is a Model:
A model is a representation of an object, system, or process. For example, a road map is a representation of an actual system of roads on the ground. Models are very useful in science. They provide a way to investigate things that are too small, large, complex, or distant t... |
NDQ_018348 | a road map is a three-dimensional model. | a. true, b. false | b | Lesson: scientific modeling
What Is a Model:
A model is a representation of an object, system, or process. For example, a road map is a representation of an actual system of roads on the ground. Models are very useful in science. They provide a way to investigate things that are too small, large, complex, or distant t... |
NDQ_018370 | basic concepts in chemistry include | a. atoms and molecules, b. chemical reactions, c. energy, d. all of the above | d | Lesson: scope of chemistry
What Is Chemistry:
Chemistry is the study of matter and energy and how they interact, mainly at the level of atoms and molecules. Basic concepts in chemistry include chemicals, which are specific types of matter, and chemical reactions. In a chemical reaction, atoms or molecules of certain t... |
NDQ_018372 | which of the following changes involve(s) chemical reactions? | a. candle burning, b. fruit spoiling, c. meat cooking, d. all of the above | d | Lesson: scope of chemistry
What Is Chemistry:
Chemistry is the study of matter and energy and how they interact, mainly at the level of atoms and molecules. Basic concepts in chemistry include chemicals, which are specific types of matter, and chemical reactions. In a chemical reaction, atoms or molecules of certain t... |
NDQ_018391 | important physics concepts include | a. motion, b. forces, c. energy, d. all of the above | d | Lesson: scope of physics
The Scope of Physics:
Physics is the study of energy, matter, and their interactions. Its a very broad field because it is concerned with matter and energy at all levelsfrom the most fundamental particles of matter to the entire universe. Some people would even argue that physics is the study ... |
NDQ_018392 | which of the following is an example of a force? | a. magnetism, b. motion, c. light, d. none of the above | a | Lesson: scope of physics
The Scope of Physics:
Physics is the study of energy, matter, and their interactions. Its a very broad field because it is concerned with matter and energy at all levelsfrom the most fundamental particles of matter to the entire universe. Some people would even argue that physics is the study ... |
NDQ_018393 | which of the following is a form of energy? | a. gravity, b. sound, c. matter, d. two of the above | b | Lesson: scope of physics
The Scope of Physics:
Physics is the study of energy, matter, and their interactions. Its a very broad field because it is concerned with matter and energy at all levelsfrom the most fundamental particles of matter to the entire universe. Some people would even argue that physics is the study ... |
NDQ_018400 | examples of screws include | a. wood screws, b. spiral staircases, c. bottle caps, d. all of the above | d | Lesson: screw
What Is A Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move obje... |
NDQ_018401 | uses of screws include | a. raising objects, b. lowering objects, c. holding objects together, d. all of the above | d | Lesson: screw
What Is A Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move obje... |
NDQ_018402 | screws help us do work by increasing the | a. amount of force that is applied, b. distance over which force is applied, c. speed with which force is applied, d. two of the above | a | Lesson: screw
What Is A Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move obje... |
NDQ_018403 | the input force is applied to the inclined plane of a screw. | a. true, b. false | a | Lesson: screw
What Is A Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move obje... |
NDQ_018405 | the mechanical advantage of a screw is always less than 1. | a. true, b. false | b | Lesson: screw
What Is A Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move obje... |
NDQ_018407 | in the picture above, it takes it takes more turns of the screw on the right to go the same distance into the wood as the screw on the left. | a. true, b. false | a | Lesson: screw
What Is A Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move obje... |
NDQ_018420 | significant figures for a measurement always include | a. all the digits that can be read directly from the measuring device, b. one digit estimated by the person taking the measurement, c. at least two digits to the right of the decimal point, d. two of the above | d | Lesson: significant figures
What Are Significant Figures:
In any measurement, the number of significant figures is the number of digits thought to be correct by the person doing the measuring. It includes all digits that can be read directly from the measuring device plus one estimated digit. Look at the sketch of a b... |
NDQ_018421 | assume that you take a measurement with a metric ruler that is divided into individual millimeters. which measurement has the correct number of significant figures? | a. 21 mm, b. 21.0 mm, c. 21.00 mm, d. none of the above | b | Lesson: significant figures
What Are Significant Figures:
In any measurement, the number of significant figures is the number of digits thought to be correct by the person doing the measuring. It includes all digits that can be read directly from the measuring device plus one estimated digit. Look at the sketch of a b... |
NDQ_018422 | which of the following is a correct rule for counting significant figures? | a. leading zeroes are always significant, b. zeroes between nonzero digits are not significant, c. zeroes that show only where the decimal point falls are not significant, d. trailing zeroes are never significant | c | Lesson: significant figures
What Are Significant Figures:
In any measurement, the number of significant figures is the number of digits thought to be correct by the person doing the measuring. It includes all digits that can be read directly from the measuring device plus one estimated digit. Look at the sketch of a b... |
NDQ_018424 | when measurements are used in a calculation, the answer has the same number of significant figures as the measurement with the most signficant figures. | a. true, b. false | b | Lesson: significant figures
What Are Significant Figures:
In any measurement, the number of significant figures is the number of digits thought to be correct by the person doing the measuring. It includes all digits that can be read directly from the measuring device plus one estimated digit. Look at the sketch of a b... |
NDQ_018430 | work is calculated with the equation work = force/distance. | a. true, b. false | b | Lesson: simple machines
What Is A Machine:
A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This forc... |
NDQ_018432 | the output distance of a machine is always | a. less than the input distance, b. greater than the input distance, c. equal to the input distance, d. none of the above | d | Lesson: simple machines
What Is A Machine:
A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This forc... |
NDQ_018433 | a machine increases the amount of work that is done. | a. true, b. false | b | Lesson: simple machines
What Is A Machine:
A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This forc... |
NDQ_018435 | if a machine increases force, it must apply the force over a longer distance. | a. true, b. false | b | Lesson: simple machines
What Is A Machine:
A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This forc... |
NDQ_018436 | machines that increase the distance over which force is applied include | a. steering wheels, b. pliers, c. rakes, d. two of the above | c | Lesson: simple machines
What Is A Machine:
A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This forc... |
NDQ_018500 | all sound waves begin with vibrating matter. | a. true, b. false | a | Lesson: sound waves
Defining Sound:
In science, sound is defined as the transfer of energy from a vibrating object in waves that travel through matter. Most people commonly use the term sound to mean what they hear when sound waves enter their ears. The tree above generated sound waves when it fell to the ground, so i... |
NDQ_018501 | vibrations spread through the air in all directions from a vibrating object. | a. true, b. false | a | Lesson: sound waves
Defining Sound:
In science, sound is defined as the transfer of energy from a vibrating object in waves that travel through matter. Most people commonly use the term sound to mean what they hear when sound waves enter their ears. The tree above generated sound waves when it fell to the ground, so i... |
NDQ_018502 | sound waves are | a. surface waves, b. transverse waves, c. longitudinal waves, d. none of the above | c | Lesson: sound waves
Defining Sound:
In science, sound is defined as the transfer of energy from a vibrating object in waves that travel through matter. Most people commonly use the term sound to mean what they hear when sound waves enter their ears. The tree above generated sound waves when it fell to the ground, so i... |
NDQ_018506 | sound waves can travel only through gases. | a. true, b. false | b | Lesson: sound waves
Defining Sound:
In science, sound is defined as the transfer of energy from a vibrating object in waves that travel through matter. Most people commonly use the term sound to mean what they hear when sound waves enter their ears. The tree above generated sound waves when it fell to the ground, so i... |
NDQ_018507 | materials that tend to absorb rather than transmit sound waves include | a. foam rubber, b. glass, c. metal, d. all of the above | a | Lesson: sound waves
Defining Sound:
In science, sound is defined as the transfer of energy from a vibrating object in waves that travel through matter. Most people commonly use the term sound to mean what they hear when sound waves enter their ears. The tree above generated sound waves when it fell to the ground, so i... |
NDQ_018508 | sound waves are mechanical waves. | a. true, b. false | a | Lesson: sound waves
Defining Sound:
In science, sound is defined as the transfer of energy from a vibrating object in waves that travel through matter. Most people commonly use the term sound to mean what they hear when sound waves enter their ears. The tree above generated sound waves when it fell to the ground, so i... |
NDQ_018509 | visible light includes all the wavelengths of light that the human eye can detect. | a. true, b. false | a | Lesson: sources of visible light
The Light We See:
Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also ... |
NDQ_018511 | some animals can see infrared or ultraviolet light. | a. true, b. false | a | Lesson: sources of visible light
The Light We See:
Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also ... |
NDQ_018514 | objects that produce light by incandescence include | a. candles, b. bonfires, c. oil lamps, d. all of the above | d | Lesson: sources of visible light
The Light We See:
Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also ... |
NDQ_018517 | substances that produce light by electroluminescence include | a. diamond, b. emerald, c. neon, d. all of the above | c | Lesson: sources of visible light
The Light We See:
Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also ... |
NDQ_018530 | speed determines how far something moves in a given amount of time. | a. true, b. false | a | Lesson: speed
Introducing Speed:
How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment.
Average Speed:
Even if speed varies during the cour... |
NDQ_018531 | the si unit for speed is | a. cm/s, b. m/s, c. m/h, d. km/h | b | Lesson: speed
Introducing Speed:
How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment.
Average Speed:
Even if speed varies during the cour... |
NDQ_018533 | if you ride your bike 20 miles and it takes you 120 minutes, what is your average speed? | a. 6 m/h, b. 10 m/h, c. 20 m/h, d. 60 m/h | b | Lesson: speed
Introducing Speed:
How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment.
Average Speed:
Even if speed varies during the cour... |
NDQ_018535 | if you know your average speed and how long you have been traveling, then you can calculate your distance with the formula | a. distance = speed/time, b. distance = speed x time, c. distance = time/speed, d. none of the above | b | Lesson: speed
Introducing Speed:
How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment.
Average Speed:
Even if speed varies during the cour... |
NDQ_018536 | to calculate the amount of time it takes to travel a given distance at a certain speed, you would use the formula | a. time = distance/speed, b. time = distance x speed, c. time = speed/distance, d. none of the above | a | Lesson: speed
Introducing Speed:
How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment.
Average Speed:
Even if speed varies during the cour... |
NDQ_018540 | the speed of sound is faster than the speed of light. | a. true, b. false | b | Lesson: speed of sound
What Is the Speed of Sound:
The speed of sound is the distance that sound waves travel in a given amount of time. Youll often see the speed of sound given as 343 meters per second. But thats just the speed of sound under a certain set of conditions, specifically, through dry air at 20 C. The sp... |
NDQ_018542 | sound waves can travel only through matter. | a. true, b. false | a | Lesson: speed of sound
What Is the Speed of Sound:
The speed of sound is the distance that sound waves travel in a given amount of time. Youll often see the speed of sound given as 343 meters per second. But thats just the speed of sound under a certain set of conditions, specifically, through dry air at 20 C. The sp... |
NDQ_018543 | sound waves generally travel most quickly through | a. gases, b. liquids, c. solids, d. plasma | c | Lesson: speed of sound
What Is the Speed of Sound:
The speed of sound is the distance that sound waves travel in a given amount of time. Youll often see the speed of sound given as 343 meters per second. But thats just the speed of sound under a certain set of conditions, specifically, through dry air at 20 C. The sp... |
NDQ_018545 | sound waves travel more quickly through dry air than moist air. | a. true, b. false | b | Lesson: speed of sound
What Is the Speed of Sound:
The speed of sound is the distance that sound waves travel in a given amount of time. Youll often see the speed of sound given as 343 meters per second. But thats just the speed of sound under a certain set of conditions, specifically, through dry air at 20 C. The sp... |
NDQ_018546 | the speed of sound through air is fastest when the air temperature is | a. 0 c, b. 20 c, c. 40 c, d. 60 c | d | Lesson: speed of sound
What Is the Speed of Sound:
The speed of sound is the distance that sound waves travel in a given amount of time. Youll often see the speed of sound given as 343 meters per second. But thats just the speed of sound under a certain set of conditions, specifically, through dry air at 20 C. The sp... |
NDQ_018563 | electric charges can travel easily through dry air. | a. true, b. false | b | Lesson: static electricity and static discharge
What Is Static Electricity:
Static electricity is a buildup of electric charges on objects. Charges build up when negative electrons are transferred from one object to another. The object that gives up electrons becomes positively charged, and the object that accepts the... |
NDQ_018566 | lighting can occur between a cloud and | a. another part of the same cloud, b. a different cloud, c. the ground, d. any of the above | d | Lesson: static electricity and static discharge
What Is Static Electricity:
Static electricity is a buildup of electric charges on objects. Charges build up when negative electrons are transferred from one object to another. The object that gives up electrons becomes positively charged, and the object that accepts the... |
NDQ_018567 | lightning is an example of static discharge. | a. true, b. false | a | Lesson: static electricity and static discharge
What Is Static Electricity:
Static electricity is a buildup of electric charges on objects. Charges build up when negative electrons are transferred from one object to another. The object that gives up electrons becomes positively charged, and the object that accepts the... |
NDQ_018568 | during a rainstorm, negative charges become concentrated at the | a. surface of the ground, b. top of the clouds, c. base of the clouds, d. two of the above | c | Lesson: static electricity and static discharge
What Is Static Electricity:
Static electricity is a buildup of electric charges on objects. Charges build up when negative electrons are transferred from one object to another. The object that gives up electrons becomes positively charged, and the object that accepts the... |
NDQ_018580 | a surface wave is one type of mechanical wave. | a. true, b. false | a | Lesson: surface wave
Waves on the Surface:
A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. Q: What do you think ... |
NDQ_018582 | an ocean wave is an example of a surface wave. | a. true, b. false | a | Lesson: surface wave
Waves on the Surface:
A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. Q: What do you think ... |
NDQ_018585 | in deep water, how do particles of water move when a surface wave passes through them? | a. up and down, b. back and forth, c. in an overall circular motion, d. all of the above | d | Lesson: surface wave
Waves on the Surface:
A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. Q: What do you think ... |
NDQ_018586 | why do surface waves break along the shore? | a. the waves start to drag on the bottom, b. the tops of the waves speed up, c. the waves become less steep, d. all of the above | a | Lesson: surface wave
Waves on the Surface:
A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. Q: What do you think ... |
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