Fluorine

9
F
Group
17
Period
2
Block
p
Protons
Electrons
Neutrons
9
9
10
General Properties
Atomic Number
9
Atomic Weight
18.9984032
Mass Number
19
Category
Halogens
Color
Colorless
Radioactive
No
From the Latin and French fluere, flow or flux
Crystal Structure
Base Centered Monoclinic
History
In 1529, Georigius Agricola described the use of fluorspar as a flux.

In 1670 Heinrich Schwandhard found that glass was etched when exposed to fluorspar treated with acid.

In 1810, French scientist Andre-Marie Ampere proposed that fluoric acid was a compound of hydrogen with a new element.

The element was finally isolated in 1886 by Henri Moissan.
Electrons per shell
2, 7
Electron Configuration
[He] 2s2 2p5
F
Fluorine reacts violently with water to produce oxygen
Physical Properties
Phase
Gas
Density
0.001696 g/cm3
Melting Point
53.53 K | -219.62 °C | -363.32 °F
Boiling Point
85.03 K | -188.12 °C | -306.62 °F
Heat of Fusion
0.26 kJ/mol
Heat of Vaporization
3.27 kJ/mol
Specific Heat Capacity
0.824 J/g·K
Abundance in Earth's crust
0.054%
Abundance in Universe
0.00004%
Fluorine
Image Credits: Images-of-elements
Fluorine gas, but only as photomontage, because fluorine reacts even with glass
CAS Number
7782-41-4
PubChem CID Number
24524
Atomic Properties
Atomic Radius
42 pm
Covalent Radius
64 pm
Electronegativity
3.98 (Pauling scale)
Ionization Potential
17.4228 eV
Atomic Volume
17.1 cm3/mol
Thermal Conductivity
0.000279 W/cm·K
Oxidation States
-1
Applications
Compounds of fluorine, including sodium fluoride, are used in toothpaste and in drinking water to prevent dental cavities.

Hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) now serve as replacements for CFC refrigerants.

Fluorine and its compounds are used in processing nuclear fuel.
Fluorine is highly toxic and corrosive
Isotopes
Stable Isotopes
19F
Unstable Isotopes
14F, 15F, 16F, 17F, 18F, 20F, 21F, 22F, 23F, 24F, 25F, 26F, 27F, 28F, 29F, 30F, 31F