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Name: Terbium Symbol: Tb
Group: Rare Earth, Lanthanides Atomic weight: 158.9254
Density @ 293 K: 8.27 g/cm3 Atomic volume: 19.2 cm3/mol
Group: Rare Earth, Lanthanides discovered: 1843


state (s, l, g): s
melting point: 1633.2 K boiling point: 3073 K
Heat of fusion: 10.80 kJ/mol Heat of vaporization: 330.90 kJ/mol


1st ionization energy: 564.7 kJ/mole
electronegativity: 1.21 2nd ionization energy: 1112 kJ/mole
electron affinity: 50 kJ/mole 3rd ionization energy: 2114 kJ/mole
Specific heat: 0.18 J/gK heat atomization: 389 kJ/mole atoms

Oxidation & Electrons:

Shells: 2,8,18,27,8,2 electron configuration: [Xe] 4f9 6s2
minimum oxidation number: 0 maximum oxidation number: 4
min. common oxidation no.: 0 max. common oxidation no.: 3

Appearance & Characteristics:

structure: hcp: hexagonal close pkd color: silvery-white
uses: alloys toxicity:
hardness: mohs characteristics: soft


reaction with air: vigorous, =>Tb4O7 (approx.)
reaction with 6M HCl: mild, =>H2, TbCl3 reaction with 6M HCl: mild, =>H2, TbCl3
reaction with 15M HNO3: mild, =>Tb(NO3)3 reaction with 6M NaOH:

Other Forms:

number of isotopes: 1 hydride(s): TbH2 TbH3
oxide(s): TbO2 Tb4O7 chloride(s): TbCl3


ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 177 pm ionic radius (1+ ion): pm
ionic radius (2+ ion): pm ionic radius (3+ ion): 106.3 pm


thermal conductivity: 11.1 J/m-sec-deg
electrical conductivity: 8.8 1/mohm-cm polarizability: 25.5 A^3


source: Monazite(phosphate),bastnaesite
rel. abund. solar system: -1.220 log abundance earth's crust: 0 log
cost, pure: 1800 $/100g cost, bulk: $/100g