Fluorine (F)

Fluorine is a chemical element with symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions.

Atomic Number

9

Atomic Mass

18.998 u

Category

halogen

Phase

gas

Density

0.001696 g/cm³

Electron Shells

2, 7

Atomic Structure

Protons: 9 • Electrons: 9 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁵

Discovery

1886 • Henri Moissan