Element 31

Gallium (Ga)

Post-transition metal · Period 4 · Group 13 · p-block

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
Boiling point
2673 K
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

IsotopeMassAbundanceStability
Ga-6968.9255860.11%Stable

Common uses

  • Semiconductors
  • LEDs
  • Solar cells
  • Thermometers

Discovery

Year
1875
Discovered by
Paul Emile Lecoq de Boisbaudran
Country
France

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