Fluorine (9)

Fluorine is a Group 17 element. Fluorine is the most electronegative and reactive of all elements. It is a pale yellow, corrosive gas, which reacts with practically all organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame. It is not uncommon to see fluorine spelled incorrectly as flourine.

•Name: Fluorine
•Symbol: F
•Atomic number: 9
•Atomic weight: 18.9984032 (5)
•Standard state: gas at 298 K
•CAS Registry ID: 7782-41-4
•Group in periodic table: 17
•Group name: Halogen
•Period in periodic table: 2
•Block in periodic table: p-block
•Color: pale yellow
•Classification: Non-metallic

Historical information

Fluorine was discovered by Henri Moissan at 1886 in France. Origin of name: from the Latin word "fluere" meaning "to flow".In 1670 a recipe containing Bohemian emerald (now known as calcium fluoride, CaF2) was used to etch glass. It seems that George Gore made a little fluorine through an electrolytic process but his apparatus exploded when the fluorine produced reacted with hydrogen from the other electrode. The element finally was isolated in 1886 by Ferdinand Frederic Henri Moisson who used an apparatus constructed from platinum. His reward was the Nobel Prize for chemistry in 1906.

Physical properties

•Melting point: 53.53 [or -219.62 °C (-363.32 °F)] K
•Boiling point: 85.03 [or -188.12 °C (-306.62 °F)] K
•Density of solid: 1700 kg m-3

Orbital properties

•Ground state electron configuration: [He].2s2.2p5
•Shell structure: 2.7
•Term symbol: 2P3/2

Isolation

It would never be necessary to make fluorine gas in most laboratories. Fluorine is available commercially in cylinders but is very difficult to handle. Fluorine may be recovered with difficulty as a highly reactive and corrosive pale yellow gas by electrolysis of hot molten mixtures (1:2) of potassium fluoride (KF) and hydrogen fluoride (HF). The electrolyte is corrosive, so is the product. Grease must be avoided because of the fire hazard. It is difficult to store as it reacts with most materials but steel and Monel metal containers may be used as the metal surfaces deactivate through the formation of unreactive surface fluorides.

Interesting Note: Hydrofluoric acid (HF) is unique among the acids as it quite readily penetrates tissues, causing liquefactive necrosis, bone erosion, and other lethal effects on one's internal systems.