Radium
Radium, the 88th element, is the only alkaline earth metal in which all isotopes
are radioactive. Radium's most stable isotope has an atomic mass of 226 amu, and a
specific gravity of 5. Its e- levels are 2-8-18-32-18-8-2, and was discovered by
Marie and Pierre Curie of France in 1898. It melts at 699.85 degrees C, and boils at
1139.85 degrees C. Prior to the 1950's, radium was used to treat some cancers. However,
at that time people did not realize that radium and calcium have similar properties,
and the radium was readily absorbed by the teeth and bones, killing bone marrow and
causing bone cancer. Ra is present in all uranium ores, as uranium decays into
radium. Radium itself has the final decomposition product of lead. Pure Ra is brilliant
white, and its nitride is black. Radium salts glow and decompose in water. Radium emits
alpha, beta, and gamma rays. When it is mixed with beryllium, it produces neutrons.
Radium 226 has a half-life of 1620 years. There are 16 known isotopes of radium.
May 19, 1997
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