At
Halogen
Astatine
Z 85A 210mass 210
Atomic model
tap a particleEvery nucleon is drawn individually — 85 protons and 125 neutrons packed into the nucleus, with 85 electrons on shells outside.
85+1
Protons
Set the element — change this and it becomes a different atom.
1250
Neutrons
Change only these and you get a different isotope of the same element.
85−1
Electrons
Sit outside the nucleus and decide the chemistry, not the element.
Element data
- Nucleons
- 210 (85 p + 125 n)
- Electron shells
- 2 · 8 · 18 · 32 · 18 · 7
- Valence shell
- 7 electrons
- Atomic mass
- 210 u
Stability
Astatine has no measured radioactive isotope in this lab — its nuclei are stable, so decay must be shown as an illustration.
Open the decay lab