ELEMENTLE

Element 31 · Metal

Gallium

Period 4 · Group 13

Gallium is a chemical element with symbol Ga and atomic number 31. Elemental gallium does not occur in free form in nature, but as the gallium(III) compounds that are in trace amounts in zinc ores and in bauxite. Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures, and melts at 29.76 °C (85.57 °F) (slightly above room temperature).

Three reasons Gallium stands out

  1. 1

    A metal that can melt in your hands.

  2. 2

    It is used in the LEDs that backlight virtually every modern smartphone screen.

  3. 3

    It can be supercooled and will remain liquid well below its freezing point without solidifying.

A metal that melts in your hand

Gallium can liquefy just above room temperature, yet it does not boil until extraordinarily hot. It expands as it freezes and can weaken aluminum by penetrating its structure. Gallium compounds are more technologically important than the pure metal, powering LEDs, lasers, and high-frequency electronics.

Gallium at a glance
Atomic number / protons31
SymbolGa
Family (Elementle)Metal
Classification (PubChem)Post-transition metal
Period4
Group13
Atomic mass (u)69.723
Standard stateSolid
Electron configuration[Ar]4s2 3d10 4p1
Reported oxidation states+3
Electronegativity (Pauling)1.81
Atomic radius (pm)187
First ionization energy (eV)5.999
Electron affinity (eV)0.3
Density (g/cm³)5.91
Melting point302.91 K (29.76 °C)
Boiling point2477 K (2,203.85 °C)
Discovery (PubChem)1875

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Gallium · Gallium on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.