What is "sodium amalgam"

Sodium \So"di*um\, n. [NL., fr.E. soda.] (Chem.) A common metallic element of the alkali group, in nature always occuring combined, as in common salt, in albite, etc. It is isolated as a soft, waxy, white, unstable metal, so highly reactive that it combines violently with water, and to be preserved must be kept under petroleum or some similar liquid. Sodium is used combined in many salts, in the free state as a reducer, and as a means of obtaining other metals (as magnesium and aluminium) is an important commercial product. Symbol Na ( Natrium). Atomic weight 22.990. Specific gravity 0.97.

Sodium amalgam, an alloy of sodium and mercury, usually produced as a gray metallic crystalline substance, which is used as a reducing agent, and otherwise.

Sodium carbonate, a white crystalline substance, Na2CO3.10H2O, having a cooling alkaline taste, found in the ashes of many plants, and produced artifically in large quantities from common salt. It is used in making soap, glass, paper, etc., and as alkaline agent in many chemical industries. Called also sal soda, washing soda, or soda. Cf. Sodium bicarbonate, and Trona.

Sodium chloride, common, or table, salt, NaCl.

Sodium hydroxide, a white opaque brittle solid, NaOH, having a fibrous structure, produced by the action of quicklime, or of calcium hydrate (milk of lime), on sodium carbonate. It is a strong alkali, and is used in the manufacture of soap, in making wood pulp for paper, etc. Called also sodium hydrate, and caustic soda. By extension, a solution of sodium hydroxide.

n. (context chemistry English) An alloy of sodium and mercury; used as a powerful reducing agent, and in certain types of sodium lamp.

Sodium amalgam, commonly denoted Na(Hg), is an alloy of mercury and sodium. The term amalgam is used for alloys, intermetallic compounds, and solutions (both solid solutions and liquid solutions) involving mercury as a major component. Sodium amalgam is often used in reactions as strong reducing agents with better handling properties compared to solid sodium. They are less dangerously reactive toward water and in fact are often used as an aqueous suspension.