←O   H↑   ↓Cl   Ne→

Fluor ∙ fluor ∙ fluoro ∙ flúor
group ‘h+h’ / hydrogen and halogens: RH

• melting point: -219.62°C
• boiling point: -188.14°C
• density: 1.58 g/l

☢ radioisotopes:
F-18 (T1/2=1.8 h) medical