Element 65
Terbium (Tb)
Terbium (Tb) is element 65 of the periodic table, a lanthanide in period 6 (f-block) with an atomic mass of 158.93 and is a solid at standard conditions.
At a glance
- Atomic number
- 65
- Symbol
- Tb
- Atomic mass
- 158.93 u
- Category
- Lanthanides
- Period
- 6
- Block
- f-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f9 5s2 5p6 6s2
- Shorthand configuration
- [Xe] 4f9 6s2
- Electrons per shell
- 2, 8, 18, 27, 8, 2
- Oxidation states
- +1, +2, +3, +4
Physical properties
- Melting point
- 1629 K
- Boiling point
- 3503 K
- Density
- 8.229 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.2
- Atomic radius
- 225 pm
- Covalent radius
- 194 pm
- First ionization energy
- 566 kJ/mol
- Electron affinity
- 50 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Tb-159 | 158.92535 | 100% | Stable |
Common uses
- Fluorescent lamps
- Magnets
- Lasers
- X-ray screens
Discovery
- Year
- 1843
- Discovered by
- Carl Gustaf Mosander
- Country
- Sweden