Atomic number: 9
Category: Non-metal - Halogen
Density at 25°C: gas, but 1.3 denser than air.
Fluorine is the first of a group (period) category called halogens. These are all very reactive elements as you follow them down the periodic table. They are so reactive that F even as F2 is very reactive.
Use, natural applications or common combinations:
- mostly present in minerals like fluorite
- Polytetrafluoroethylene (Teflon) is the most common fluoropolymer
- Around half of all mined fluorite is used directly in steel-making.
- Standard atomic weight: 18.998 4032(5)
- Melting point: −219.62 °C
- Boiling point: −188.12 °C
- Radioactivity: almost all stable
- 19F is stable but 18F only has a half life of 109minutes