Pure fluorine from the Latin fluere, for "flow" was was not isolated until by Henri Moissan, burning and even killing many scientists along the way. It has many uses today, a particular one being used in the Manhattan project to help create the first nuclear bomb. Fluorine is the most electronegative element on the periodic table, which means that it is a very strong oxidizing agent and accepts other elements' electrons.
Fluorine's atomic electron configuration is 1s 2 2s 2 2p 5. Fluorine is the most electronegative element because it has 5 electrons in it's 2P shell.
The optimal electron configuration of the 2P orbital contains 6 electrons, so since Fluorine is so close to ideal electron configuration, the electrons are held very tightly to the nucleus.
The high electronegativity of fluorine explains its small radius because the positive protons have a very strong attraction to the negative electrons, holding them closer to the nucleus than the bigger and less electronegative elements. Because of its reactivity, elemental fluorine is never found in nature and no other chemical element can displace fluorine from its compounds. Fluorine bonds with almost any element, both metals and nonmetals, because it is a very strong oxidizing agent.
It is very unstable and reactive since it is so close to its ideal electron configuration. It forms covalent bonds with nonmetals, and since it is the most electronegative element, is always going to be the element that is reduced.
It will react explosively with many elements and compounds such as Hydrogen and water. This acid is very dangerous and when dissociated can cause severe damage to the body because while it may not be painful initially, it passes through tissues quickly and can cause deep burns that interfere with nerve function. There are also some organic compounds made of Fluorine, ranging from nontoxic to highly toxic.
Fluorine forms covalent bonds with Carbon, which sometimes form into stable aromatic rings. The reaction goes:. Fluorine also forms strong ionic compounds with metals. Some common ionic reactions of Fluorine are:.
Compounds of fluorine are present in fluoridated toothpaste and in many municipal water systems where they help to prevent tooth decay. And, of course, fluorocarbons such as Teflon have made a major impact on life in the 20th century.
It also reacts with many compounds forming fluorides, and many organic compounds inflame and burn in the gas. The highly reactive nature is due to the weak F-F bond thermodynamically unstable , which provides a low activation energy to reactions kinetically unstable. Since the fluoride ion is small 1. In general the highest oxidation states for any metal are found with the fluoride salts. The large ionization energies needed to produce the cations are recovered by the high lattice energies.
The high electronegativity of fluorine means that it forms a single electron pair bond polar bond with a high ionic character. The polar nature of the bond means that there is a large inductive effect within a molecule. In contrast, the low polarizability of the fluorine means that the inter-molecular van der Waals bonds are very weak.
Thus, even with very high molecular weights the boiling point can be very low, e. While many fluorides are salts, when the metal is in its higher oxidation states e. Hydrogen fluoride HF is converted to highly corrosive hydrofluoric acid upon contact with moisture. Pure hydrogen fluoride must be handled in metal or polythene vessels, while aqueous solutions will readily etch and dissolve standard laboratory glassware requiring the use of fluorinated polymer e.
Hydrogen fluoride is synthesized by the reaction of a fluoride salt with a concentrated acid, Fluorine is extremely reactive, and as it will attack glass and metals careful choice of reaction vessel is needed. Moissan used a platinum U-shaped tube to extract the fluorine Gas. Other oxidising agents have less positive standard electrode potentials, e. The more positive the standard electrode potential is the better the oxidising agent.
Fluorine oxidises all non-metals except helium He , nitrogen N 2 , neon Ne and argon Ar. Fluorine even reacts with the usually unreactive and precious metals; gold Au and platinum Pt. All the halogens, except fluorine, dissolve in water making aqueous solutions.
Fluorine is different, because it oxidises water to oxygen whilst is reduced to hydrogen fluoride. Fluorine can also react with water to produce ozone O 3. When fluorine oxidises other elements it tends to oxidise them to their highest possible oxidation states, e.
The small size of a fluorine atom means that many fluorine atoms can fit around a central atom. SF 6 is used in electrical insulation and has the opposite effect to helium on the human voice when inhaled, that is, it makes the voice sound deeper. UF 6 "Molecule of the Month" August is used to separate radioisotopes. The surprisingly weak F-F bond kJ mol -1 compared to the other halogens is a result of fluorine having such small atoms, which brings the lone pairs close enough to experience electrostatic repulsion as indicated by the arrows.
Fluorine is not a very abundant element but it is one which is widely distributed in different minerals as its anion, fluoride F -. Some of the main minerals containing fluoride are fluorspar CaF 2 also known as fluorite, cryolite Na 3 AlF 6 used as a solvent in the electrolysis of aluminium oxide and fluorapatite 3Ca 3 PO 4 2.
Ca ClF found in teeth. It was possible to get flouride treatment from the s at a dentists to help strengthen the enamel of teeth. The picture below shows the effect of UV light on fluorite. Fluorescence in crystals under UVm light. The hydrogen fluoride is electrolysed in the present of potassium fluoride KF to form potassium bifluoride KHF 2 to make elemental flourine as described earlier.
Fluorine containing compounds are used also as fluxes when extracting iron and aluminium from its ore.
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