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Gaffer Variety:
Elements 9 SN2 011:
By Willie Gaffer:
Fluorine:
Fluorine, Symbol F in the periodic table, is a pale-yellow, highly corrosive, poisonous, gaseous halogen element. It is a bit heavier than air and is the most electronegative and most reactive of all the elements. It is used in a wide variety of industrially important compounds. The atomic number is 9, the atomic weight is 18.9984, the freezing point is -219.62°C, the melting point -223°C, the boiling point is -188.14°C, and the specific gravity of liquid is 1.151 (in the liquid state at the boiling point). It has a valence of 1.
Fluorine combines directly with most elements and indirectly
with nitrogen, chlorine, and oxygen. Nearly all compounds are decomposed by
fluorine to form fluorides that are among the most stable of all chemical
compounds. Fluorine occurs naturally in the combined form as fluorite, cryolite,
and apatite. Fluorite, from which most fluorine compounds are generally
derived, is commonly mined in the
The preparation of fluorine as a free element is difficult and seldom done, since free fluorine is very reactive. However, gaseous fluorine can be prepared by electrolytic techniques, and liquid fluorine may be prepared by passing the gas through a metal or rubber tube surrounded by liquid air.
Hydrofluoric acid (hydrogen fluoride, HF or H2F2), is one of the most important fluorine compounds. It is manufactured by heating calcium fluoride in sulfuric acid. The aqueous solution of this acid, generally used commercially, is obtained by passing the anhydrous hydrogen fluoride vapors into a leaden receiver containing distilled water, thus yielding the acid in dilute form. Hydrofluoric acid is extremely corrosive and must be preserved in lead, steel, or plastic containers. Hydrofluoric acid dissolves glass, making the acid useful for various forms of glass etching, such as marking the divisions on thermometer tubes and etching designs into glassware and ceramics. Another fluorine compound, hydrofluosilicic acid, combines with such bases as sodium and potassium to form salts called fluosilicates or silicofluorides.
Fluorine and many fluorides, such as hydrogen fluoride and sodium fluoride, are extremely poisonous. Drinking water containing excessive amounts of fluorides causes tooth enamel to become brittle and to chip off, leaving a stained or mottled effect. The proper proportion of fluorides in drinking water, however, has been found to greatly reduce tooth decay.
Fluorine compounds have many applications. The chlorofluorocarbons, odorless and nonpoisonous liquids or gases such as Freon, are used as a dispersing agent in aerosol sprays and as a refrigerant. In the nineteen seventies, it was suspected that these chemicals reached the stratosphere and were destroying the earth's ozone layer. These suspicions were proven in the eighties and Freon use was phased out.
Teflon, a fluorine plastic that is very resistant to most chemical action, is widely used to make such products as motor gaskets and dashboard accessories in the automobile industry. Teflon is also used as a coating on the inner surface of frying pans and other kitchen utensils to reduce the need for fat in cooking. Many organic fluorine compounds developed during World War II became commercially viable and found many uses in industry.
Neon:
Neon, symbol Ne in the periodic table. Is a rare, inert gaseous element which is found in the atmosphere in the minute amount of 18 parts per million. That is enough to be extracted through fractional distillation of liquid air. It takes 88,000 pounds of liquid air to yield one pound of neon. Neon is colorless but glows reddish orange in an electric discharge and is used in display and television tubes. The atomic number is 10, the atomic weight is 20.183, the melting point is -248.67°C, and the boiling point is -245.95°C.
Neon is in group 8A of the periodic table making it one of the so-called noble gases. The most prevalent application is in display signs of one form or another. Other uses of neon include use in television tubes, gas lasers, and high-voltage indicators such as timing lights used by automotive mechanics and engineers. There are no known stable compounds of neon. Molecules of the element consist of single atoms. Natural neon is a mixture of three stable isotopes. These are neon-20, neon-21, and neon-22.
Sodium:
Sodium, symbol Na, is a soft, light, extremely malleable silver-white metallic element that reacts explosively with water. It has a hardness of 0.4. It is naturally abundant in combined forms, especially in common salt, and is used in the production of a wide variety of industrially important compounds. The atomic number is 11, the atomic weight is 22.99, the melting point is 97.8°C the boiling point is 892°C,and the specific gravity is 0.971. The valence of sodium is 1 putting it in group 1A of the periodic table.
Sodium is used in many household products, including table salt and baking soda. In its pure form, it reacts explosively with water and oxidizes immediately upon exposure to the atmosphere. So, even though sodium is the sixth most abundant element in the earth’s crust, it is never found as a free element.
Sodium is found in nature in some kind of combined state. It occurs in the ocean and in salt lakes as sodium chloride, NaCl, and less often as sodium carbonate, Na2CO3, and sodium sulfate, Na2SO4. Sodium is prepared commercially by the electrolytic decomposition of fused sodium chloride. It is also a necessary ingredient of plant and animal tissue.
Sodium is used in the manufacture of tetraethyl lead and as
a cooling agent in nuclear reactors. Although tetraethyl lead was once used as
an antiknock octane enhancer in gasoline, it has been phased out for two
reason. First and most important was that it produced poisonous emissions of
lead in the atmosphere. It also poisoned the catalytic converters that were
used by automakers to reduce emission problems. The Clean Air Act of 1990
required oil companies to make available cleaner gasoline with a higher oxygen
content in polluted urban areas, beginning in 1992. You will not find leaded
gasoline at any fueling station in