ElementsWhat is gallium?
Gallium is a soft, silvery metal with a melting point of about 30 degrees Celsius, so it can melt in a warm hand. It was predicted by Mendeleev before it was found.
What is gallium used for?
LEDs, lasers, fast electronic chips for phones, and solar cells for satellites.
Where the name comes from
From Gallia, the Latin name for France, the home country of its discoverer.
Key facts
- Symbol
- Ga
- Atomic number
- 31
- Atomic mass
- 69.723 u
- Family
- Post-transition metal
- Period
- 4
- Group
- 13
- Block
- p
- State at room temperature
- Solid
- Melting point
- 29.8 °C (302.91 K, 86 °F)
- Boiling point
- 2,204 °C (2,477 K, 3,999 °F)
- Density
- 5.91 g/cm³
- Electrons per shell
- 2, 8, 18, 3
- Electron configuration
- [Ar]4s2 3d10 4p1
- Common oxidation states
- +3
- Electronegativity (Pauling)
- 1.81
- First ionisation energy
- 5.999 eV
- Electron affinity
- 0.3 eV
- Atomic radius (van der Waals)
- 187 pm
- Discovered
- 1875
Place in the periodic table
Gallium is element number 31. It sits in period 4 (row 4) of the periodic table, in group 13 (column 13), and belongs to the p-block. Just before it comes zinc (30), and just after it comes germanium (32). In the same column, aluminium is above it and indium is below it. Elements in one column tend to behave alike.
Family: Post-transition metals.
Physical properties
At room temperature gallium is a solid. It melts at 29.8 °C and boils at 2,204 °C, so it stays liquid over a range of 2,174 degrees. Its density is 5.91 grams per cubic centimetre, so a one-litre block would weigh about 5.91 kilograms. By density it ranks 59th among the 96 elements with a measured value.
Inside the atom
An atom of gallium has 31 protons in its nucleus and, when neutral, 31 electrons around it. The electrons are arranged in 4 shells: 2, 8, 18, 3. The outermost shell holds 3 electrons. Written in full, the electron configuration is [Ar]4s2 3d10 4p1.
Its electronegativity on the Pauling scale is 1.81. This number shows how strongly an atom pulls shared electrons towards itself: fluorine, the strongest, is 3.98. Removing one electron from an atom takes 5.999 electronvolts (about 579 kilojoules per mole). One mole of gallium weighs 69.723 grams, so a single gram contains about 8.64 × 1021 atoms.
The ring picture is a simple model that only counts the electrons in each shell. Real atoms do not look like this.
Next steps
- Work out the weight of a compound that contains gallium with the molar mass calculator.
- Compare it with every other element in the sortable list.
- Test yourself with the symbol quiz.
Figures on this page are from PubChem (U.S. National Library of Medicine), as downloaded on 11 November 2026. See About and data sources.