Gallium (Ga)
[Ar] 3d¹⁰ 4s² 4p¹. 1 unpaired electron, period 4, group 13, p block.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
GaGallium, Z = 31, 69.723 u
[Ar] 3d10 4s2 4p1
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹
- Blockp block
- Period4
- Group13
- Valence3
- Unpaired1
- MagneticPara
Last electron 4p
- n4shell
- l1p subshell
- m−1orbital
- s+½spin up
Step by step
- Gallium has 31 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p¹.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹.
- Replace the argon core with [Ar]: [Ar] 3d¹⁰ 4s² 4p¹.
Gallium (Ga): the numbers
| Atomic number | 31 |
|---|---|
| Atomic mass | 69.723 u |
| Period | 4 |
| Group | 13 |
| Block | p block |
| Valence electrons | 3 |
| Unpaired electrons | 1 |
| Magnetic | paramagnetic |
| Last electron | 4p: n = 4, l = 1, m = −1, s = +1/2 |
Gallium (Ga): quick answers
What is the electronic configuration of gallium?
Gallium has 31 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹, or [Ar] 3d¹⁰ 4s² 4p¹ in short.
How many unpaired electrons does gallium have?
Gallium has 1 unpaired electron, so it is paramagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of gallium?
The last electron goes into 4p: n = 4, l = 1, m = −1, s = +1/2. Orbitals fill from m = −l up, spin +½ first.