Natural fluoride is represented by one stable isotope with an atomic number 19. Artificially were prepared and other isotopes of substances with atomic masses of 16, 18, 20, 21. All of them are unstable.
first fluorine compound - fluorspar CaF2, or fluorite, was described at the end of the XV century under the name of "Fleur".Swedish chemist Carl Scheele in 1771 for the first time received a hydrofluoric acid HF.The existence of the fluorine atom was predicted in 1810, and in a free form, it was isolated in 1886 by Henri Moissan in the electrolysis of anhydrous hydrogen fluoride liquid.
configuration of the electron layer of fluorine - 2s (2) 2p (5).In compounds it exhibits a constant oxidation state of -1.In Mendelee
v's periodic table of elements is fluorine in the second period.
Fluorine has the highest electron affinity, and the largest among all elements of the value of electronegativity - 4. It is the most active non-metal.Boiling point fluorine -188,14˚C, melting point - 219,62˚C.The gas density F2 - 1,693 kg / m ^ 3.
Like all halogens, fluorine exists as diatomic molecules.The dissociation energy of the F2 molecule atoms is anomalously low - only 158 kJ, which partly explains the high reactivity of the substance.
Fluoride exhibits the highest reactivity.It does not form compounds with only three noble gases - helium, neon and argon.With many substances, both complex and simple, fluorine reacts directly.For example, water is often said, "burning" in an atmosphere of fluorine:

2H2 + 2H2O = 4HF + O2.
with hydrogen fluoride reacts very active, with a blast:

H2 + F2 = 2HF.

obtained in the course of the reaction of hydrogen fluoride HF is unlimited soluble in water to form a weak hydrofluoric acid.
with fluorine reacts most non-metals - graphite, silicon, all halogens, sulfur, and others.Bromine and iodine under an atmosphere of fluorine ignited at an ordinary temperature, and reacted with chlorine by heating them to 200-250˚C.
oxygen, nitrogen, diamond, carbon dioxide and carbon monoxide gases directly with fluorine do not respond.Indirectly it was obtained nitrogen trifluoride NF3, fluorides and oxygen O2F2 OF2.Recent connections - the only ones in which the degree of oxidation of oxygen different from the usual for him (-2).
at low heat (up to 100-250˚C) to react with fluorine take silver, rhenium, osmium, and vanadium.At higher temperatures fluoride begins to interact with the gold, niobium, titanium, chromium, aluminum, iron, copper and others.