Heaviest of the alkaline earth metals, radium is intensely radioactive and resembles barium chemically. This metal is found (combined) in minute quantities in the uranium ore pitchblende, and various other uranium minerals. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, and gamma rays. Radium also produces neutrons when mixed with beryllium.
When freshly prepared, pure radium metal is brilliant white, but blackens when exposed to air (probably due to nitride[?] formation). Radium is luminescent, decomposes in water and is a bit more volatile than barium.
The only practical uses of radium are derived from its radiative properties. More recently discovered radioisotopes, such as cobalt-60 and cesium-137, are replacing radium in even these limited uses because several of these are much more powerful and others are safer to handle.
One gram of radium yields ~0.0001 ml of radon gas each day which is used in cancer and other treatments.
Formerly used in self-luminous paints for watch, clock and instrument dials.
During the 1930s it was found that worker exposure to radium by handling luminescent paints caused serious health effects which included sores, anemia and bone cancer[?]. This use of radium was stopped soon afterward. Handling of radium has since been blamed for Curie's premature death.
Its compounds (which are short lived) color flames crimson carmine (rich red or crimson color with a shade of purple) and give a characteristic spectrum. Due to its very short half life and intense radioactivity, radium compounds are quite rare occurring almost exclusively in uranium ores.
Radium has 25 different isotopes, four of which are found in nature, with radium-226 being the most common and stable. Ra-223, Ra-224, Ra-226 and Ra-228 are all generated in the decay of either U or Th. Ra-226 is a product of U-238 decay, and is the longest-lived isotope of Ra with a half-life of 1602 years; next longest is Ra-228, a product of Th-232 breakdown, with a half-life of 6.7 years.
Radium is over 1 million times more radioactive than the same amount of uranium.
Its decay occurs in at least seven stages; the successive main products have been studied and are called radium emanation or exradio, radium A, radium B, radium C, etc. (The emanation is a heavy gas, the later products are solids.) These products are regarded as unstable 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 a final product of disintegration. The curie is 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).
Radium is poisonous. Radium is extremely radioactive and its decay product radon is a deadly lung hazard. Since Ra is closely related to calcium, it has the potential for causing great harm by substituting for it in bone. Inhalation, injection, or body exposure to radium can cause cancer and other body disorders. Stored radium should be ventilated to prevent build-up of radon.
Emitted energy from the decay of radium ionizes gases, affects photographic plates, causes sores on the skin, and produces many other dramatic effects. The degree of activity depends on the proportion of radium present and not whether it is chemically combined.
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