Element 31
Gallium
Post-transition metals
Gallium (Ga) is in the p-block of the periodic table — group 13, period 4.
Gallium is a chemical element with symbol Ga and atomic number 31.
Key data
- Atomic number
- 31
- Atomic mass
- 69.723 u
- Group / Period
- 13 / 4
- Block
- p-block
- Phase at STP
- Solid
- Density
- 5.91 g/cm³
- Melting point
- 29.8 °C
- Boiling point
- 2399.8 °C
- Electron configuration
- [Ar] 3d10 4s2 4p1
Periodic table block
Gallium is in the p-block (group 13, period 4). Elements land in the p-block when their highest-energy electrons fill a p subshell — this region holds most nonmetals, the metalloids, and the metals on the right of the table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •LEDs
- •Solar cells
- •Liquid metal at body temperature
Discovery
Year: 1875
Discovered by: Lecoq de Boisbaudran
Frequently asked questions
What is the atomic number of Gallium?
Gallium has atomic number 31. Its symbol is Ga and its atomic mass is 69.723 u.
What category of element is Gallium?
Gallium is classified as post-transition metals. It sits in group 13, period 4 of the periodic table.
What block of the periodic table is Gallium in?
Gallium is in the p-block (group 13, period 4). Its highest-energy electrons occupy the p subshell — you can see this in its electron configuration, [Ar] 3d10 4s2 4p1.
What is Gallium used for?
Common uses of Gallium include: LEDs, Solar cells, Liquid metal at body temperature.
When was Gallium discovered?
Gallium was discovered in 1875 by Lecoq de Boisbaudran.
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