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Atomic Number: 88
Atomic Symbol: Ra
Atomic Weight: 226
Melting Point: 1,292 F (700 C)
Boiling Point: 3,159 F (1,737 C)
Word origin: The word radium comes from radius, the Latin word for rays.
Discovery: Marie Curie discovered radium in 1898. She uncovered it while in North Bohemia, where it occurs in pitchblende or uraninite. In 1911, Curie and André-Louis Debierne isolated the element through the electrolysis of a solution of pure radium chloride. This solution employed a mercury cathode and on distillation in an atmosphere of hydrogen, it yielded the pure metal of radium.
Properties of radium
Radium is a member of the alkaline earth group of metals, and is luminescent, as are its slats. Radium decomposes in water and is somewhat more volatile than barium. It emits alpha-, beta-, and gamma-rays when mixed with beryllium produce neutrons. [See Periodic Table of the Elements]
When freshly prepared and in its pure state, radium is brilliant white. It blackens, however, when exposed to air, probably because of nitride formation. When exposed to a flame, radium imparts the fire with a carmine red color.
One gram of Ra-226 undergoes 3.7 x 1010 disintegrations per second. The curie as a measurement unit is defined as the amount of radioactivity that has the same disintegration rate as 1 gram of Ra-226.Over the course of 25 years, radium will lose about 1 percent of its activity, being transformed into an element of lower atomic weight, such as lead.
It is important that stored radium and radium-containing products or minerals be ventilated to prevent build-up of the gas radon. Inhalation, injection, or other bodily exposure to radium can cause cancer and other disorders.
Sources of radium
Radium was originally obtained from the element-rich pitchblende ore in Joachimsthal, Bohemia — where Curie found it. It can also be obtained from the carnotite sands of Colorado and ores in Republic of Zaire and the Great Lakes region of Canada.
Today, radium is principally obtained for commercial use as bromide and chloride because it is doubtful that any significant stock of isolated radium still exists. Radium is present in all uranium minerals, however, and could be extracted if desired. There are extensive wastes of uranium processing as well as large uranium deposits in Ontario, Australia, New Mexico, Utah and elsewhere.
Uses of radium
Radium’s most well-known use is in cancer treatments and therapies for other diseases. Though radon, the gas of radium, is what is actually used in treatments, radium supplies radon. One gram of radium produces about 0.0001 ml (stp) of radon gas per day. The radon gas is purged from the radium and sealed in minute tubes, which are also called needles and seeds. In this form, the treatment is administered to the patient.
Radium was formerly used in producing self-luminous paints and neutron sources. Today, other radioisotopes, such as Cobalt-60, are used instead of radium. Some of these more popular sources are much more powerful, and others are safer to use.
(Source: Los Alamos National Laboratory)