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- Sodium
-
- Life could not exist without compounds of sodium. These compounds hold
- water in body tissues, and a severe deficiency of sodium can cause death.
- Blood contains sodium compounds in solution. Sodium compounds are used in
- industry in the manufacture of chemicals and pharmaceuticals, in metallurgy,
- in sodium vapor lamps, and in the production of hundreds of every day
- products. One of the most common sodium compounds is table salt, or sodium
- chloride. In its pure form sodium is a silver-white, soft and waxy metallic
- element. It is the sixth most abundant element on Earth and occurs in more
- that trace amounts in the stars and sun.
- The secret that led to low-cost production was learned in 1789, when the
- French chemist Nicolas Leblanc discovered how to make soda out of common
- salt. The compound called soda is sodium carbonate. Crude sodium carbonate
- is called soda ash. The carbonate also combines with water in crystals known
- as washing soda, or sal soda. Soda is used in manufacturing soap, glass,
- dyestuffs, and explosives and as the basis for making other sodium compounds.
- Other sodium compounds, with some of their uses, are: baking soda(sodium
- bicarbonate), an ingredient of baking powder; borax (sodium borate), a food
- preservative; and caustic soda, or lye (sodium hydroxide), used in
- soapmaking. Some properties of sodium are: Symbol Na, Atomic Number 11,
- Atomic Weight 22.9898, Boiling Point 1,621.2 F, and Melting Point 208.06 F.
- Sodium belongs to the group of elements known as alkali metals. It is never
- found uncombined in nature and was first isolated by the English scientist
- Sir Humphry Davy in 1807. Lighter than water, pure sodium can be cut with a
- knife at room temperature and is brittle at low temperatures. It conducts
- heat and electricity easily and exhibits a photoelectric effect, that is, it
- emits electrons when exposed to light. In its pure form, sodium oxidizes
- instantly when exposed to the air and reacts vigorously with water, seizing
- the oxygen and a part of the hydrogen to form sodium hydroxide. The
- remaining hydrogen is liberated and may ignite from the heat of the reaction.
- Pure metallic sodium --usually obtained by the electrolysis of sodium
- hydroxide-- must be stored in kerosene to keep it from air and moisture. One
- of the few uses of pure sodium is in vapor lamps along highways.
-