11Na Sodium

Year Discovered

1807

Discovered By

Sir Humphry Davy of England

Biological Rating

Necessary for all life.

Description

Sodium’s name is derived from the English word soda. Much like lithium, sodium is a light, very soft, silvery-white metal. It is even softer than lithium and can be cut with a knife. Sodium is very reactive with air and water. If a sufficient quantity comes in contact with water, sodium can actually explode. Sodium’s low density allows it to float on water, although placing a large quantity of sodium in water would not be a good idea. Sodium is a very common element in the universe, being the fourth most abundant element on the Earth and very common in stars. Sodium light spectra is used by astronomers to identify stars that are similar to our Sun. The metal itself is used in making drugs, organic compounds and dyes. Due to its low melting point and high heat capacity, it also is used as a coolant in certain types of nuclear reactors. Sodium is replacing mercury in streetlights, providing a yellow-orange light, rather than the bluish-gray light of mercury vapor lights. Sodium compounds are used for a wide variety of household products, such as baking soda, lye, and table salt. Soap is a compound of sodium with fatty acids. Sodium carbonate (soda ash) is an important industrial chemical and used in making glass, paper, detergents and water treatment chemicals. Sodium’s symbol (Na) comes from its Latin name natrium.

Biological Benefits

Critical for life processes in animals and plants. Biological Benefits Sodium is critical to most species. It is necessary in the functioning of the nervous system and the brain. Humans require two to three grams of sodium daily, but excess sodium chloride is unhealthy for the cardiovascular system.

Role in Life Processes

Percentage Amount in the Human Body: 0.14%

Sources

Most sodium is obtained by electrolysis of molten mineral sodium chloride (halite). Some is obtained from trona and soda ash. It occurs in many other minerals as well, including amphibole, zeolite and cryolite. Halite is mined in the USA China, Germany, Russia and Canada. Trona and soda ash are mined in the USA (Wyoming and California), Kenya, Mexico and Botswana.