Radium

When freshly prepared, pure radium metal is brilliant white, but blackens when exposed to air (probably due to barium. The normal phase of radium is a solid.

Applications

Some of the few practical uses of radium are derived from its radioactive properties. More recently discovered ¹³⁷Cs, are replacing radium in even these limited uses because several of these isotopes are more powerful emitters, safer to handle, and available in more concentrated form.

When mixed with neutron source for physics experiments.

Historical uses

Radium was formerly used in tritium's beta radiation is potentially dangerous if ingested, it has replaced radium in these applications.

During the 1930s it was found that workers exposure to radium by handling Radium Girl" employees who had used radium-based luminous paints on the dials of watches and clocks had a significant impact on the formulation of occupational disease labor law.

Radium was also put in some foods for taste and as a preservative, but also exposed many people to radiation. Radium was once an additive in products like toothpaste, hair creams, and even food items due to its supposed curative powers. Such products soon fell out of vogue and were prohibited by authorities in many countries, after it was discovered they could have serious adverse health effects. (See for instance Radithor.) Spas featuring radium-rich water are still occasionally touted as beneficial, such as those in Misasa, Tottori, Japan.

Radium (usually in the form of radon gas which in turn is used as a cancer treatment. The isotope ²²³Ra is currently under investigation for use in medicine as cancer treatment of bone metastasis.

History

Radium (Latin radius, ray) was spectral lines which had never been documented before. The Curies announced their discovery to the French Academy of Sciences on 26 December 1898.

In 1902, radium was isolated as a pure hydrogen gas.

Historically the decay products of radium were known as radium A, B, C, etc. These are now known to be isotopes of other elements as follows:

	Isotope
Radium emanation	²²²Rn
Radium A	²¹⁸Po
Radium B	²¹⁴Pb
Radium C	²¹⁴Bi
Radium C₁	²¹⁴Po
Radium C₂	²¹⁰Tl
Radium D	²¹⁰Pb
Radium E	²¹⁰Bi
Radium F	²¹⁰Po

On February 4, 1936 radium E became the first radioactive element to be made synthetically.

One unit for radioactivity, the non-Radioactivity).

Occurrence

Radium is a Carnotite sands in Colorado provide some of the element, but richer ores are found in the Democratic Republic of the Congo and the Great Lakes area of Canada, and can also be extracted from uranium processing waste. Large uranium deposits are located in Ontario, New Mexico, Utah, Virginia, Australia, and in other places.

Compounds

Its spectrum. Due to its geologically short half life and intense radioactivity, radium compounds are quite rare, occurring almost exclusively in uranium ores.

radium fluoride (RaF₂)
Cl₂)
radium bromide (RaBr₂)
radium iodide (RaI₂)
radium oxide (RaO)
radium nitride (Ra₃N₂)

See also radium compounds.

Isotopes

Radium has 25 different known half-life of 1602 years; next longest is ²²⁸Ra, a product of ²³²Th breakdown, with a half-life of 6.7 years.

Radioactivity

Radium is over one million times more radioactive than the same mass of Radon is a heavy gas and the later products are solids. These products are themselves radioactive elements, each with an atomic weight a little lower than its predecessor.

Radium loses about 1% of its activity in 25 years, being transformed into elements of lower atomic weight with lead being the final product of disintegration.

The SI unit of radioactivity is the becquerel (Bq), equal to one disintegration per second. The curie is a non-SI unit defined as that amount of radioactivity which has the same disintegration rate as 1 gram of Ra-226 (3.7 x 10¹⁰ disintegrations per second, or 37 GBq).

Safety

Handling of radium has been blamed for Marie Curie's premature death.

Radium is highly radioactive and its decay product, radon gas, is also radioactive. Since radium is chemically similar to calcium, it has the potential to cause great harm by replacing it in bones. Inhalation, injection, ingestion or body exposure to radium can cause cancer and other disorders. Stored radium should be ventilated to prevent accumulation of radon.

Emitted energy from the decay of radium ionizes gases, affects photographic plates, causes sores on the skin, and produces many other detrimental effects.

References

Albert Stwertka (1998). Guide to the Elements - Revised Edition. Oxford University Press. ISBN 0-19-508083-1.
Radium. Los Alamos National Laboratory (Chemistry Operations) (December 18, 2003). Retrieved on 2007-12-25.
Denise Grady. "A Glow in the Dark, and a Lesson in Scientific Peril", The New York Times, October 6, 1998. Retrieved on 2007-12-25.
Nanny Fröman (1 December 1996). Marie and Pierre Curie and the Discovery of Polonium and Radium. Nobel Foundation. Retrieved on 2007-12-25.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Radium". A list of authors is available in Wikipedia.