Terbium (Tb)

From Wikipedia, the free encyclopediaTerbium is a chemical element with symbol Tb and atomic number 65. It is a silvery-white rare earth metal that is malleable, ductile and soft enough to be cut with a knife. Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime and euxenite.

Terbium in the periodic table

SymbolTb
Atomic number65
Group0
Period6
Blockf
Element categoryLanthanide

Physical properties

Phase at STPSolid
Density8.23 g/cm3
Atomic weight158.925 u
Melting point1629 K
1355.85 °C
2472.53 °F
Boiling point3396 K
3122.85 °C
5653.13 °F

Atomära egenskaper

Electronegativity (Pauling Scale)1.1
Electron affinity112.4 kJ/mol
Ionization energies
1565.8 kJ/mol
2 1110 kJ/mol
3 2114 kJ/mol
4 3839 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f9 5s2 5p6 6s2
Electrons per shell2, 8, 18, 27, 8, 2

History

Discovered1843
Discovered byCarl Gustaf Mosander