Ga
Post-transition metal
Gallium
Z 31A 70mass 69.723
Atomic model
tap a particleEvery nucleon is drawn individually — 31 protons and 39 neutrons packed into the nucleus, with 31 electrons on shells outside.
31+1
Protons
Set the element — change this and it becomes a different atom.
390
Neutrons
Change only these and you get a different isotope of the same element.
31−1
Electrons
Sit outside the nucleus and decide the chemistry, not the element.
Element data
- Nucleons
- 70 (31 p + 39 n)
- Electron shells
- 2 · 8 · 18 · 3
- Valence shell
- 3 electrons
- Atomic mass
- 69.723 u
Stability
Gallium has no measured radioactive isotope in this lab — its nuclei are stable, so decay must be shown as an illustration.
Open the decay lab