Atomic number 31
Gallium
Post-transition metal
Quick facts
- Atomic mass
- 69.723
- Group
- 13
- Period
- 4
- State (STP)
- solid
- Electronegativity
- 1.81
- Common ox. states
- +3
Properties
Electron configuration
[Ar] 3d¹⁰ 4s² 4p¹
- Ionization energy
- 578.8 kJ/mol
- Electron affinity
- 41.0 kJ/mol
- Melting point
- 302.91 K (29.8 °C)
- Boiling point
- 2673.00 K (2399.8 °C)
How it bonds
Gallium normally shows +3 (Ga₂O₃, GaCl₃) — predictable group-13 behavior. Famous for melting at body temperature (29.76 °C); a gallium spoon will melt in a cup of tea. Used in GaAs (gallium arsenide) semiconductors.