The element terbium is named after the town of Ytterby in Sweden. It is a silvery metal that can be obtained from the mineral monazite. This element has only a few uses. Pure terbium is added to other metals to make powerful magnets that are used in devices that produce sound. Its compounds are used to coat mercury lamps.

Summary of properties (Tb)

Atomic weight158.925354(8)
Discoverer (year)Mosander, Carl Gustav (1843)
Natural formmetallic solid (hexagonal)
Electron configuration[Xe] 49 6s2
Melting point (ºC)1360
Boiling point (ºC)3041
Abundance in earth's crust (ppm)1.2
Isotope (abundance)159Tb (100)
Density g/cm38.23
Van der Waals radius (pm)233
Covalent radius (pm)181
Electronegativity (Pauling)
Vaporization enthalpy (kJ/mol)319.00
Enthalpy of fusion (kJ/mol)10.15
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.18
Thermal conductivity (W/cm·K) at 25ºC and 1 atm0.110
Oxidation state+3
Electron affinity (eV)>1.165
1st Ionization potential (eV)5.8638

Back to the Periodic Table of the Elements.