Fluorine

General:

Name:Fluorine Symbol:F
Type:Halogen Atomic weight:18.998403
Density @ 293 K: 0.001696 g/cm3 Atomic volume:17.1 cm3/mol
Discovered:

In 1530 Georgius Agricola noted the use of the mineral fluorspar (principally calcium fluoride) as a flux - it was added to the metal ores while they were processed in furnaces to promote fusing of the pure metal. The element fluorine was first isolated by Henri Moissan in 1886. Fluorine is an extremely hazardous element and earlier attempts to isolate it had lead to several blindings and fatalities. The origin of the name comes from the Latin word 'fluere', meaning to flow - hence the word flux.

States

State (s, l, g):gas
Melting point:53.6 K (-219.6 °C) Boiling point:85.1 K (-188.1 °C)

Energies

Specific heat capacity:0.82 J g-1 K-1 Heat of atomization:79 kJ mol-1
Heat of fusion:0.510 kJ mol-1 of F2 Heat of vaporization : 6.62 kJ mol-1 of F2
1st ionization energy:1681 kJ mol-1 2nd ionization energy:3374.1 kJ mol-1
3rd ionization energy:6050.3 kJ mol-1 Electron affinity:328 kJ mol-1

Oxidation & Electrons

Shells:2,7 Electron configuration:[He] 2s2 2p5
Minimum oxidation number:-1 Maximum oxidation number:0
Min. common oxidation no.:-1 Max. common oxidation no.:0
Electronegativity (Pauling Scale):3.98 Polarizability volume:0.634 Å3

Appearance & Characteristics

Structure:cubic crystals in solid phase Color:pale yellow
Hardness:mohs
Harmful effects:

Fluorine is highly toxic and corrosive.

Characteristics:

Fluorine is the most reactive and the most electronegative of all the elements.

Fluorine is a pale yellow, diatomic, highly corrosive, flammable gas, with a pungent odor. It is the lightest halogen.

It reacts violently with water to produce oxygen and the extremely corrosive hydrofluoric acid.


Uses:

Fluorine and its compounds are used in uranium processing and in the production of fluorochemicals, including many high-temperature plastics such as Teflon.

Compounds of fluorine, including sodium fluoride, are used in toothpaste and in drinking water to prevent dental cavities.

Hydrofluoric acid can dissolve glass and is used to etch the glass in light bulbs and in other products.

Chlorofluorocarbons (CFCs) were used in as refrigerants in air conditioning units and freezers but they have now been banned because they contribute to ozone depletion.

Reactions

Reaction with air:none Reaction with 6 M HCl:vigorous, ⇒ HF, OF2, ClF3
Reaction with 15 M HNO3:⇒ NO3F Reaction with 6 M NaOH:vigorous, ⇒ O2, NaF

Compounds

Oxide(s):OF2 Chloride(s):ClF, ClF3, ClF5
Hydride(s):HF (fluoric acid)

Radius

Atomic radius:50 pm Ionic radius (1+ ion): pm
Ionic radius (2+ ion): pm Ionic radius (3+ ion): pm
Ionic radius (2- ion): pm Ionic radius (1- ion):119 pm

Conductivity

Thermal conductivity:0.0277 W m-1 K-1 Electrical conductivity: S cm-1

Abundance & Isotopes

Abundance earth's crust:585 parts per million by weight, 104 part per million by moles
Abundance solar system:500 parts per billion by weight, 30 parts per billion by moles
Cost, pure:$190 per 100g
Cost, bulk:$ per 100g
Source:

In nature, fluorine occurs mainly in the minerals fluorspar (CaF2) and cryolite (Na3AlF6). Commercially, production of fluorine involves the electrolysis of a mixture of molten potassium fluoride and hydrofluoric acid. Fluorine gas forms at the anode, and hydrogen gas at the cathode.

Isotopes:

Fluorine has 11 isotopes whose half-lives are known, with mass numbers 15 to 25. Of these only one is stable, 19F.

Other

Other: