Ga
Gallium
Element 31 · Post-transition metal
Gallium (Ga)
Gallium is a soft, silvery metal that melts in your hand at 29.8 °C. Its compounds are essential in LEDs and high-speed electronics.
- Post-transition metal
- Period 4
- Group 13
- p-block
- solid at room temperature
Key properties
- Atomic mass
- 69.723
- u
- Electron configuration
- [Ar] 3d10 4s2 4p1
- Melting point
- 29.8 °C
- 302.91 K
- Boiling point
- 2,203.9 °C
- 2,477 K
- Density
- 5.91 g/cm³
- Electronegativity
- 1.81
- Pauling
- Atomic radius
- 187 pm
- van der Waals
- 1st ionisation energy
- 5.999 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about gallium
- 01
Mendeleev predicted gallium as “eka-aluminium” and corrected its discoverer’s density measurement.
- 02
Gallium stays liquid over one of the widest temperature ranges of any element — almost 2,400 °C.
- 03
Gallium expands when it freezes, like water.
Applications
What is gallium used for?
- LEDs and laser diodes (GaN, GaAs)
- Solar panels
- Smartphone radio chips
- Medical imaging
History
Discovery & name origin
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 31
- Atomic mass
- 69.723 u
- Group
- 13
- Period
- 4
- Block
- p-block
- Electron configuration
- [Ar] 3d10 4s2 4p1
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1
- Electrons per shell
- 2, 8, 18, 3
- Electronegativity (Pauling)
- 1.81
- Electron affinity
- 0.3 eV
- Atomic radius (van der Waals)
- 187 pm
- Stable isotopes
- 2
Oxidation states
Highlighted: common oxidation states (+3).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st578.8
- 2nd1,979.3
- 3rd2,963
- 4th6,180
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 302.91 K · 29.8 °C · 85.6 °F
- Boiling point
- 2,477 K · 2,203.9 °C · 3,998.9 °F
- Density
- 5.91 g/cm³
- Molar heat capacity
- 25.86 J/(mol·K)
- Appearance
- Silver-white
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Gallium questions
What is Ga on the periodic table?
Ga is the symbol for gallium, element 31 on the periodic table. It sits in group 13, period 4, in the post-transition metal category, and has an atomic mass of 69.723.
What is the atomic number of gallium?
Gallium has atomic number 31, so every gallium atom has 31 protons in its nucleus. Its symbol is Ga and its atomic mass is 69.723.
Who discovered gallium?
Gallium was discovered by Paul-Émile Lecoq de Boisbaudran in 1875 (France). The name comes from Latin Gallia, “France”.
What is gallium used for?
Gallium is used for: LEDs and laser diodes (GaN, GaAs); solar panels; smartphone radio chips; medical imaging.
Is gallium a metal?
Yes. Gallium is a post-transition metal, one of the metallic elements.
What is the electron configuration of gallium?
The electron configuration of gallium is [Ar] 3d10 4s2 4p1. Its 31 electrons are arranged in shells as 2, 8, 18, 3.