Element 31
Gallium (Ga)
Gallium (Ga) is element 31 of the periodic table, a post-transition metal in period 4, group 13 (p-block) with an atomic mass of 69.723 and is a solid at standard conditions.
At a glance
- Atomic number
- 31
- Symbol
- Ga
- Atomic mass
- 69.723 u
- Category
- Post-transition metals
- Period
- 4
- Group
- 13
- Block
- p-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1
- Shorthand configuration
- [Ar] 3d10 4s2 4p1
- Electrons per shell
- 2, 8, 18, 3
- Oxidation states
- -5, -4, -2, -1, +1, +2, +3
Physical properties
- Melting point
- 302.91 K (29.76 °C)
- Boiling point
- 2,673 K (2,399.85 °C)
- Density
- 5.907 g/cm³
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.81
- Atomic radius
- 136 pm
- Covalent radius
- 122 pm
- Van der Waals radius
- 187 pm
- First ionization energy
- 579 kJ/mol
- Electron affinity
- 29 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Ga-69 | 68.92558 | 60.11% | Stable |
Common uses
- Semiconductors
- LEDs
- Solar cells
- Thermometers
Discovery
- Year
- 1875
- Discovered by
- Paul Emile Lecoq de Boisbaudran
- Country
- France
Frequently asked questions
- Is gallium a metal?
- Yes. Gallium is a metal, classified as a post-transition metal on the periodic table.
- How many protons does gallium have?
- Gallium has 31 protons. Its atomic number is 31, which is also the number of electrons in a neutral atom of gallium.
- What group and period is gallium in?
- Gallium is in group 13 and period 4 of the periodic table, in the p-block.
- What is the atomic mass of gallium?
- The atomic mass of gallium is 69.723 u (unified atomic mass units).
Keep exploring
Gallium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.