Radium

Description

A naturally occurring radioactive element. Radium occurs in uranium ores, such as pitchblende, at concentrations of approximately 10-7 ppm. Radium was discovered in 1898 by the Curies. It is a disintegration product of Uranium. Radium is a bright white metal. It undergoes spontaneous disintegration to form Radon gas and alpha rays. Radium was formerly used to make luminous paints used in clock dials, doorknobs, and other glow-in-the-dark items prior to the 1970s.

Synonyms and Related Terms

Ra

Risks

• Highly toxic radioactive element.
• Destroys living tissue.
• NIST: SDS

Physical and Chemical Properties

Soluble in water with the evolution of hydrogen. Radium salts burn with a carmine red flame color. Half life = 1622 years.

Composition	Ra (atomic no. 88)
CAS	7440-14-4
Melting Point	700 C
Density	5.0-5.5 g/ml
Molecular Weight	atomic wt = 226.026
Boiling Point	1140 C

Resources and Citations

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 649

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 8277

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Edward Reich, Carlton J. Siegler, Consumer Goods: How to Know and Use Them, American Book Company, New York City, 1937