Chemical element with atomic number 61 (Pm)
Promethium, 61 Pm Pronunciation (proh-MEE -thee-əm ) Appearance metallic Mass number [145]
Atomic number (Z ) 61 Group f-block groups (no number)Period period 6 Block f-block Electron configuration [Xe ] 4f5 6s2 Electrons per shell 2, 8, 18, 23, 8, 2 Phase at STP solid Melting point 1315 K (1042 °C, 1908 °F) Boiling point 3273 K (3000 °C, 5432 °F) Density (at 20° C) α-145 Pm: 7.149 g/cm3 α-147 Pm: 7.247 g/cm3 [ 1] Heat of fusion 7.13 kJ/mol Heat of vaporization 289 kJ/mol Oxidation states common: +3
+2? Electronegativity Pauling scale: 1.13 (?) Ionization energies 1st: 540 kJ/mol 2nd: 1050 kJ/mol 3rd: 2150 kJ/mol Atomic radius empirical: 183 pm Covalent radius 199 pm Spectral lines of promethiumNatural occurrence from decay Crystal structure double hexagonal close-packed (dhcp) (hP4 ) Lattice constants a = 0.36393 pmc = 1.1739 pm (at 20 °C)[ 1] Thermal expansion 9.0× 10−6 /K (at r.t. )[ 2] [ a] Thermal conductivity 17.9 W/(m⋅K) Electrical resistivity est. 0.75 µΩ⋅m (at r.t. ) Magnetic ordering paramagnetic [ 3] Young's modulus α form: est. 46 GPa Shear modulus α form: est. 18 GPa Bulk modulus α form: est. 33 GPa Poisson ratio α form: est. 0.28 CAS Number 7440-12-2 Discovery Charles D. Coryell , Jacob A. Marinsky , Lawrence E. Glendenin (1945) Named by Grace Mary Coryell (1945)
Category: Promethium | references
child table, as reused in {IB-Pm}
^ a b c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements . Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9 .
^ Cverna, Fran (2002). "Ch. 2 Thermal Expansion". ASM Ready Reference: Thermal properties of metals (PDF) . ASM International. ISBN 978-0-87170-768-0 .
^ Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5 .
^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF) . Chinese Physics C . 45 (3): 030001. doi :10.1088/1674-1137/abddae .
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