31 Ga 69.723
Gallium
Post-Transition Metal
Gallium (Ga) is a chemical element with atomic number 31, classified as a post-transition metal. At room temperature it is a solid. It was discovered in 1875 by Lecoq de Boisbaudran.
Properties
- Atomic number
- 31
- Atomic mass
- 69.723 u
- Category
- Post-Transition Metal
- Group
- 13
- Period
- 4
- Block
- p-block
- Electron configuration
- [Ar] 3d¹⁰ 4s² 4p¹
- Phase at STP
- Solid
- Density
- 5.907 g/cm³
- Melting point
- 302.91 K (29.8 °C)
- Boiling point
- 2477 K (2203.8 °C)
- Electronegativity
- 1.81
- Atomic radius
- 136 pm
- Ionization energy
- 5.999 eV
- Discovery
- 1875 · Lecoq de Boisbaudran
Common uses
LEDs, semiconductors, solar panels, thermometers
Did you know?
Melts in your hand at 29.8°C but is essential for modern electronics.