(From the
Latin fluor, "
flux") A
corrosive,
toxic, greenish-yellow
gaseous chemical element, the lightest of the
halogens and the most
reactive chemical
element, forming
fluorides with almost all known
elements.
Symbol: F
Atomic number: 9
Atomic weight: 18.9984032
Density (at 0°C with 101,325 pascals): 1.696 g/L
Melting point: -219.62°C
Boiling point: -188.1°C
Valence: -1
Ground state electron configuration: [He]2s22p5