Not to be confused with Ytterbium . For the hacker group sometimes called YTTRIUM, see Cozy Bear . Yttrium is a chemical element ; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element ".[7] Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89 Y is the only stable isotope and the only isotope found in the Earth's crust .
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Yttrium, 39 Y Pronunciation (IT -ree-əm ) Appearance silvery white
Atomic number (Z ) 39 Group group 3 Period period 5 Block d-block Electron configuration [ Kr ] 4d1 5s2 Electrons per shell 2, 8, 18, 9, 2 Phase at STP solid Melting point 1799 K (1526 °C, 2779 °F) Boiling point 3203 K (2930 °C, 5306 °F) Density (at 20° C) 4.469 g/cm3 [3] when liquid (at m.p. ) 4.24 g/cm3 Heat of fusion 11.42 kJ/mol Heat of vaporization 363 kJ/mol Molar heat capacity 26.53 J/(mol·K) Vapor pressure
P (Pa)
1
10
100
1 k
10 k
100 k
at T (K)
1883
2075
(2320)
(2627)
(3036)
(3607)
Oxidation states 0,[4] +1, +2, +3 (a weakly basic oxide) Electronegativity Pauling scale: 1.22 Ionization energies 1st: 600 kJ/mol 2nd: 1180 kJ/mol 3rd: 1980 kJ/mol Atomic radius empirical: 180 pm Covalent radius 190±7 pm Spectral lines of yttriumNatural occurrence primordial Crystal structure hexagonal close-packed (hcp) (hP2 )Lattice constants a = 364.83 pmc = 573.17 pm (at 20 °C)[3] Thermal expansion 11.21× 10−6 /K (at 20 °C)[3] [lower-alpha 1] Thermal conductivity 17.2 W/(m⋅K) Electrical resistivity α, poly: 596 nΩ⋅m (at r.t. ) Magnetic ordering paramagnetic [5] Molar magnetic susceptibility +2.15× 10−6 cm3 /mol (2928 K)[6] Young's modulus 63.5 GPa Shear modulus 25.6 GPa Bulk modulus 41.2 GPa Speed of sound thin rod 3300 m/s (at 20 °C) Poisson ratio 0.243 Brinell hardness 200–589 MPa CAS Number 7440-65-5 Naming after Ytterby (Sweden) and its mineral ytterbite (gadolinite) Discovery Johan Gadolin (1794)First isolation Friedrich Wöhler (1838)
Category: Yttrium | references
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The most important present-day use of yttrium is as a component of phosphors , especially those used in LEDs . Historically, it was once widely used in the red phosphors in television set cathode ray tube displays.[8] Yttrium is also used in the production of electrodes , electrolytes , electronic filters , lasers , superconductors , various medical applications, and tracing various materials to enhance their properties.
Yttrium has no known biological role. Exposure to yttrium compounds can cause lung disease in humans.[9]