Atomic number 65
Terbium
Lanthanide
In the real world
Quick facts
- Atomic mass
- 158.93
- Group
- –
- Period
- 6
- State (STP)
- solid
- Electronegativity
- 1.20
- Common ox. states
- +3
Properties
Electron configuration
[Xe] 4f⁹ 6s²
- Ionization energy
- 565.8 kJ/mol
- Electron affinity
- 50.0 kJ/mol
- Melting point
- 1629.00 K (1355.8 °C)
- Boiling point
- 3503.00 K (3229.8 °C)
How dangerous is it?
1/5 · Low risk
The green phosphor in fluorescent lamps and screens comes from terbium. It is a soft, low-toxicity metal whose only real caution is its flammable dust.
- FlammableImmediate
Powdered terbium can catch fire in air; the solid form only tarnishes. (as filings or powder, not the solid)
Handle filings clear of flame; the solid metal is safe to work with.
How it bonds· family overview
Terbium (Tb) is a lanthanide - a soft, silvery metal that almost always loses 3 electrons to form a +3 ion (Ln³⁺). Its 4f electrons sit deep below the valence shell, so chemistry across the lanthanide row is remarkably similar: oxide, fluoride, chloride salts, all in the +3 state.
