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= = = Marriage = = = |
Once , Khandoba and Mhalsa play a game of saripat ( translated as game of dice or chess ) . Khandoba loses everything to Mhalsa in the wager , except his dhoti , his flag , his staff ( wand ) and his bhandari , the bag of magical bhandara ( turmeric powder ) . In a dream , he sees Banai and falls in love with her . He... |
Khandoba is described as doing odd jobs under Banai 's orders . Banai first assigns him the task of sweeping the entire vada . He is responsible for cleaning the sheep pens and taking the sheep and lambs for grazing . He completes all tasks by spreading his magical bhandara . The shepherds are astonished how a single ... |
The wedding is deemed not in accordance to Hindu rituals . Banai and Khandoba marry in a simple , un @-@ Brahmanical ceremony , where sheep droppings are showered on the couple , instead of rice as in the ritualistic weddings of classical ( Brahmanical ) Hinduism . The wedding is conducted without a Brahmin officiatin... |
= = = After marriage = = = |
In all versions , Khandoba returns to Jejuri with his new wife and faces the wrath of Mhalsa . Many songs tell about the confrontations of Mhalsa and Banai . In some songs , Mhalsa complains about Khandoba 's infatuation with the impure Banai . The cantankerous Mhalsa grumbles how Banai has polluted the house by her u... |
Rarely , Banai also appears in Khandoba 's chief legend where he slays the demons Mani and Malla . Mhalsa and Banai ( or Ganga ) futilely help Khandoba in the battle to collect the blood of Mani , every drop of which was creating a new demon . Finally , the dog of Khandoba swallows all the blood . Rarely , Banai is de... |
= = Worship and iconography = = |
While traces of Banai / Balai 's association with the folk god Biroba as a " mother " remain , Banai rarely enjoys independent worship in modern times . She is generally worshipped as Khandoba 's consort . While in Karnataka , her temple is outside the village and Mailara ( as Khandoba is known in Karnataka ) journeys... |
Banai is the patron goddess of the Dhangars and the protector goddess of flock and herds . She takes care of the well @-@ being of the community and is worshipped for increasing the herd . Stone votive images of sheep and other cattle are offered to her for plentiful animals . No animal sacrifice or non @-@ vegetarian... |
Khandoba is often depicted with two identical goddesses accompanying him , representing Mhalsa and Banai . In brass images , Banai is depicted holding a lamb and offering water to Khandoba , while Mhalsa rides with Khandoba on his horse . In metal plaques worshipped by the Dhangars , Banai accompanies Khandoba on his ... |
= Europium = |
Europium is a chemical element with symbol Eu and atomic number 63 . It was isolated in 1901 and is named after the continent of Europe . It is a moderately hard , silvery metal which readily oxidizes in air and water . Being a typical member of the lanthanide series , europium usually assumes the oxidation state + 3 ... |
= = Characteristics = = |
= = = Physical properties = = = |
Europium is a ductile metal with a hardness similar to that of lead . It crystallizes in a body @-@ centered cubic lattice . Some properties of europium are strongly influenced by its half @-@ filled electron shell . Europium has the second lowest melting point and the lowest density of all lanthanides . |
Europium becomes a superconductor when it is cooled below 1 @.@ 8 K and compressed to above 80 GPa . This is because europium is divalent in the metallic state , and is converted into the trivalent state by the applied pressure . In the divalent state , the strong local magnetic moment ( J |
= 7 / 2 ) suppresses the superconductivity , which is induced by eliminating this local moment ( J = |
0 in Eu3 + ) . |
= = = Chemical properties = = = |
Europium is the most reactive rare earth element . It rapidly oxidizes in air , so that bulk oxidation of a centimeter @-@ sized sample occurs within several days . Its reactivity with water is comparable to that of calcium , and the reaction is |
2 Eu + 6 H2O → 2 Eu ( OH ) 3 + 3 H2 |
Because of the high reactivity , samples of solid europium rarely have the shiny appearance of the fresh metal , even when coated with a protective layer of mineral oil . Europium ignites in air at 150 to 180 ° C to form europium ( III ) oxide : |
4 Eu + 3 O2 → 2 Eu2O3 |
Europium dissolves readily in dilute sulfuric acid to form pale pink solutions of the hydrated Eu ( III ) , which exist as a nonahydrate : |
2 Eu + 3 H2SO4 + 18 H2O → 2 [ Eu ( H2O ) 9 ] 3 + + 3 SO2 − |
4 + 3 H2 |
= = = = Eu ( II ) vs. Eu ( III ) = = = = |
Although usually trivalent , europium readily forms divalent compounds . This behavior is unusual to most lanthanides , which almost exclusively form compounds with an oxidation state of + 3 . The + 2 state has an electron configuration 4f7 because the half @-@ filled f @-@ shell gives more stability . The + 2 state i... |
= = = Isotopes = = = |
Naturally occurring europium is composed of 2 isotopes , 151Eu and 153Eu , with 153Eu being the most abundant ( 52 @.@ 2 % natural abundance ) . While 153Eu is stable , 151Eu was recently found to be unstable to alpha decay with half @-@ life of 5 + 11 |
− 3 × 1018 years , giving about 1 alpha decay per two minutes in every kilogram of natural europium . This value is in reasonable agreement with theoretical predictions . Besides the natural radioisotope 151Eu , 35 artificial radioisotopes have been characterized , the most stable being 150Eu with a half @-@ life of 3... |
The primary decay mode for isotopes lighter than 153Eu is electron capture , and the primary mode for heavier isotopes is beta minus decay . The primary decay products before 153Eu are isotopes of samarium ( Sm ) and the primary products after are isotopes of gadolinium ( Gd ) . |
= = = = Europium as a nuclear fission product = = = = |
Europium is produced by nuclear fission , but the fission product yields of europium isotopes are low near the top of the mass range for fission products . |
Like other lanthanides , many isotopes , especially isotopes with odd mass numbers and neutron @-@ poor isotopes like 152Eu , have high cross sections for neutron capture , often high enough to be neutron poisons . |
151Eu is the beta decay product of samarium @-@ 151 , but since this has a long decay half @-@ life and short mean time to neutron absorption , most 151Sm instead ends up as 152Sm . |
152Eu ( half @-@ life 13 @.@ 516 years ) and 154Eu ( half @-@ life 8 @.@ 593 years ) cannot be beta decay products because 152Sm and 154Sm are non @-@ radioactive , but 154Eu is the only long @-@ lived " shielded " nuclide , other than 134Cs , to have a fission yield of more than 2 @.@ 5 parts per million fissions . A... |
155Eu ( half @-@ life 4 @.@ 7612 years ) has a fission yield of 330 parts per million ( ppm ) for uranium @-@ 235 and thermal neutrons ; most of it is transmuted to non @-@ radioactive and nonabsorptive gadolinium @-@ 156 by the end of fuel burnup . |
Overall , europium is overshadowed by caesium @-@ 137 and strontium @-@ 90 as a radiation hazard , and by samarium and others as a neutron poison . |
= = = Occurrence = = = |
Europium is not found in nature as a free element . Many minerals contain europium , with the most important sources being bastnäsite , monazite , xenotime and loparite . |
Depletion or enrichment of europium in minerals relative to other rare earth elements is known as the europium anomaly . Europium is commonly included in trace element studies in geochemistry and petrology to understand the processes that form igneous rocks ( rocks that cooled from magma or lava ) . The nature of the ... |
Divalent europium ( Eu2 + ) in small amounts is the activator of the bright blue fluorescence of some samples of the mineral fluorite ( CaF2 ) . The reduction from Eu3 + to Eu2 + is induced by irradiation with energetic particles . The most outstanding examples of this originated around Weardale and adjacent parts of ... |
= = Production = = |
Europium is associated with the other rare earth elements and is , therefore , mined together with them . Separation of the rare earth elements is a step in the later processing . Rare earth elements are found in the minerals bastnäsite , loparite , xenotime , and monazite in mineable quantities . The first two are or... |
4 ( Ln denotes a mixture of all the lanthanides except promethium ) , and the third is a fluorocarbonate LnCO3F . Monazite also contains thorium and yttrium , which complicates handling because thorium and its decay products are radioactive . For the extraction from the ore and the isolation of individual lanthanides ... |
A few large deposits produce or produced a significant amount of the world production . The Bayan Obo iron ore deposit contains significant amounts of bastnäsite and monazite and is , with an estimated 36 million tonnes of rare earth element oxides , the largest known deposit . The mining operations at the Bayan Obo d... |
= = Compounds = = |
Europium compounds tend to exist trivalent oxidation state under most conditions . Commonly these compounds feature Eu ( III ) bound by 6 – 9 oxygenic ligands , typically water . These compounds , the chlorides , sulfates , nitrates , are soluble in water or polar organic solvent . Lipophilic europium complexes often ... |
= = = Halides = = = |
Europium metal reacts with all the halogens : |
2 Eu + 3 X2 → 2 EuX3 ( X = F , Cl , Br , I ) |
This route gives white europium ( III ) fluoride ( EuF3 ) , yellow europium ( III ) chloride ( EuCl3 ) , gray europium ( III ) bromide ( EuBr3 ) , and colorless europium ( III ) iodide ( EuI3 ) . Europium also forms the corresponding dihalides : yellow @-@ green europium ( II ) fluoride ( EuF2 ) , colorless europium (... |
= = = Chalcogenides and pnictides = = = |
Europium forms stable compounds with all of the chalcogens , but the heavier chalcogens ( S , Se , and Te ) stabilize the lower oxidation state . Three oxides are known : europium ( II ) oxide ( EuO ) , europium ( III ) oxide ( Eu2O3 ) , and the mixed @-@ valence oxide Eu3O4 , consisting of both Eu ( II ) and Eu ( III... |
Eu2O3 + 3 H2S → 2 EuS + 3 H2O + S |
The main nitride is europium ( III ) nitride ( EuN ) . |
= = History of study = = |
Although europium is present in most of the minerals containing the other rare elements , due to the difficulties in separating the elements it was not until the late 1800s that the element was isolated . William Crookes observed the phosphorescent spectra of the rare elements and observed spectral lines later assigne... |
Europium was first found in 1890 by Paul Émile Lecoq de Boisbaudran , who obtained basic fractions from samarium @-@ gadolinium concentrates which had spectral lines not accounted for by samarium or gadolinium . However , the discovery of europium is generally credited to French chemist Eugène @-@ Anatole Demarçay , w... |
When the europium @-@ doped yttrium orthovanadate red phosphor was discovered in the early 1960s , and understood to be about to cause a revolution in the color television industry , there was a scramble for the limited supply of europium on hand among the monazite processors , as the typical europium content in monaz... |
Frank Spedding , celebrated for his development of the ion @-@ exchange technology that revolutionized the rare earth industry in the mid @-@ 1950s , once related the story of how he was lecturing on the rare earths in the 1930s when an elderly gentleman approached him with an offer of a gift of several pounds of euro... |
= = Applications = = |
Relative to most other elements , commercial applications for europium are few and rather specialized . Almost invariably , they exploit its phosphorescence , either in the + 2 or + 3 oxidation state . |
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