Sodium

NAME: Sodium

ALTERNATIVE NAME/S:

DETAILS/DESCRIPTION:  Sodium is a soft, silvery white metal that belongs to the group of chemical elements known as ‘alkali metals.’  Its chemical symbol is Na.  It is the sixth most common element on Earth, making up 2.8 percent of the planet’s crust.  Highly reactive, sodium is found only in compounds in nature and never as a single element.  When exposed to air, it immediately combines with oxygen.  To obtain pure sodium, the metal must be extracted from the compounds.  In 1807, English chemist Sir Humphry <first obtained in pure form by> Davy* became the first person to accomplish this, using electric current to extract it from sodium hydroxide. 

Sodium compounds are essential to living organisms, serving important biological functions.  In the human body, sodium compounds hold water in body tissues and can be found in blood, helping to maintain a normal flow of water between the body fluids and the cells.  A severe deficiency of sodium could cause death.  However, too much sodium—often a result of unhealthy eating habits—can cause high blood pressure and other health problems.

Sodium’s industrial uses are numerous.  Sodium chloride, deposited in dry lakes, underground, and in seawater, is popularly known as table salt.  Sodium carbonate is used in photography.  Sodium carbonate decahydrate (washing soda) serves as a household cleaning agent and as a bleach for cotton and linen.  Sodium bicarbonate is used in dry-chemical fire extinguishers and as an ingredient in baking soda and fizzy beverages. 

ONELINER: Sodium

OTHER CONNECTIONS: None

BIBLIOGRAPHY:

"Sodium." Britannica Student Encyclopedia. 2004.  Encyclopædia Britannica Online. 25 May 2004 search.eb.com/ebi/article?eu=299248.

Shriver, Duward F. "Sodium." World Book Online Reference Center. 2004. World Book, Inc. 27 May 2004. 0www.worldbookonline.com.mill1.sjlibrary.org:80/wb/Article?id=ar518140.