9 F 18.998

Fluorine

diatomic nonmetal

Properties

Atomic number
9
Atomic mass
18.998 u
Category
diatomic nonmetal
Group
17
Period
2
Block
p-block
State (room temp)
Gas
Outer-shell electrons
7
Electronegativity
3.98 (Pauling)
Density
Melting point
-219.67 °C
Boiling point
-188.12 °C

Electron configuration

1s² 2s² 2p⁵

Noble-gas shorthand: [He] 2s² 2p⁵

Electrons per shell: 2, 7 — that's 7 in the outermost shell.

See how electron configuration is built →

F
Bohr model — outer-shell electrons in blue

About Fluorine

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. As the most electronegative element, it is extremely reactive:almost all other elements, including some noble gases, form compounds with fluorine.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.