F
Halogen
Fluorine
Z 9A 19mass 18.998
Atomic model
tap a particleEvery nucleon is drawn individually — 9 protons and 10 neutrons packed into the nucleus, with 9 electrons on shells outside.
9+1
Protons
Set the element — change this and it becomes a different atom.
100
Neutrons
Change only these and you get a different isotope of the same element.
9−1
Electrons
Sit outside the nucleus and decide the chemistry, not the element.
Element data
- Nucleons
- 19 (9 p + 10 n)
- Electron shells
- 2 · 7
- Valence shell
- 7 electrons
- Atomic mass
- 18.998 u
Stability
Fluorine has no measured radioactive isotope in this lab — its nuclei are stable, so decay must be shown as an illustration.
Open the decay lab