Sr
Alkaline earth metal
Strontium
Z 38A 88mass 87.62
Atomic model
tap a particleEvery nucleon is drawn individually — 38 protons and 50 neutrons packed into the nucleus, with 38 electrons on shells outside.
38+1
Protons
Set the element — change this and it becomes a different atom.
500
Neutrons
Change only these and you get a different isotope of the same element.
38−1
Electrons
Sit outside the nucleus and decide the chemistry, not the element.
Element data
- Nucleons
- 88 (38 p + 50 n)
- Electron shells
- 2 · 8 · 18 · 8 · 2
- Valence shell
- 2 electrons
- Atomic mass
- 87.62 u