Fluorine

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Fluorine,  9F
General properties
Name, symbol Fluorine, F
Allotropes Alpha, beta
Appearance Gas: very pale yellow
Liquid: bright yellow
Solid: alpha is opaque, beta is transparent
Fluorine in the periodic table
-

F

Cl
OxygenFluorineNeon
Atomic number 9
Standard atomic weight (Ar) 18.998403163(6)
Group, block (halogens); p-block
Period period 2
Electron configuration [He] 2s2 2p5
per shell
2, 7
Physical properties
Pale yellow
Phase Gas
Melting point 53.48 K ​(−219.67 °C, ​−363.41 °F)
Boiling point 85.03 K ​(−188.11 °C, ​−306.60 °F)
Density at  (0 °C and 101.325 kPa) 1.696 g/L
when liquid, at  1.505 g/cm3
Triple point 53.48 K, ​​90 kPa
Critical point 144.41 K, 5.1724 MPa
Heat of 6.51 kJ/mol
 pressure
Atomic properties
Oxidation states −1
Electronegativity Pauling scale: 3.98 (most electronegative element)
energies 1st: 1681 kJ/mol
2nd: 3374 kJ/mol
3rd: 6147 kJ/mol
Covalent radius 64 pm
Van der Waals radius 135 pm
Miscellanea
Crystal structure ​Cubic
Thermal conductivity 0.02591 W/(m·K)
CAS Registry Number 7782-41-4
History
Naming After the mineral fluorite, itself named after Latin fluo (to flow, in smelting)
Discovery André-Marie Ampère (1810)
First isolation Henri Moissan (26 June 1886)
Named by Humphry Davy
· references

Fluorine is a halogen too toxic and far too reactive to be considered for use in a home chemistry setting. It is one of the most powerful oxidizers known. Fluorine has the chemical symbol F.

Properties

Chemical

Fluorine is so reactive that it will react and oxidize most known substances, often bursting them into flames if done near room temperature. This includes glass and unpassivated steel.

When the gas is needed, a specialized nickel alloy (commonly monel or some other cupronickel alloy) is used for any tubing as it forms a passivation layer that prevents the destructive oxidation that would occur if any other material was used.

Physical

Fluorine is a pale yellow color, although very specialized equipment is needed to see this color. It is nearly impossible to store in a way that it can be viewed, due to its extreme reactivity.

Availability

Very few businesses have or need the facilities to cope with elemental fluorine, so obtaining a cylinder of the gas is basically impossible (and suicidal without highly specialized equipment).

Even element samples are virtually impossible to make or obtain due to the inability to store fluorine without it reacting. Since the reaction product of water, hydrogen fluoride, reacts with glass even at very low concentrations, calcium fluoride is often substituted for fluorine in an element collection. It may, however, be possible to store impure fluorine mixed with helium in a nearly perfectly dry quartz tube, without risking contamination or destruction of the sample. In a quartz tube that is, to the fullest extent possible, perfectly dry, pure fluorine can be stored and is as such available that way, although very expensively so.

Preparation

A method of producing fluorine purely chemically was discovered, but it is highly obscure and requires chemicals like antimony pentafluoride (which requires fluorine to be produced anyway). The only method, therefore, is electrolysis of molten ammonium or potassium bifluoride. Needless to say, this procedure is difficult to safely perform even by professional chemists.

Projects

  • Do something else

Handling

Safety

Do not attempt to make this gas. There's a reason some of the people who did research on fluorine are known as "fluorine martyrs." Apart from extreme reactivity issues, all fluoride salts are highly toxic, and high amounts of toxic hydrogen fluoride will be made in any attempt. There are much better things to do in chemistry, so why not try something that you will survive. Neither is it a cheap, useful, or painless way to commit suicide, as it starts fires on contact with anything it touches.

Storage

Not possible in all but the most advanced professional labs, as it will react with almost everything. Some chemical suppliers may sell special vials containing diluted mixtures of helium and fluorine gas as element collecting samples.

Disposal

If elemental fluorine was somehow produced, you need to vent it outside.

References

Relevant Sciencemadness threads