Claudia Sanders, age 13, of Santa Cruz, Calif., for her question:
WHO DISCOVERED RADIUM?
Radium is a very rare and precious element. It was discovered and named in 1898 by a husband and wife team of French physicists named Pierre and Marie Curie.
The Curies obtained the new element from pitchblende, an ore containing uranium. Scientists had previously discovered that uranium gave off radiation. However, radiation from the Curies' new radium were far more intense than those from uranium.
Pierre and Marie Curie extracted a few grains of radium chloride, a salt of radium, from a huge amount of pitchblende. This radium chloride, weight for weight, gave off rays that were nearly a million times as intense as the rays that had been observed to be given off from uranium.
The discovery of radium, which came just three years after the discovery of X rays, marked a turning point in the history of modern physics. It led to further investigation of the nature of the atom and it also was one of the early steps that led to the release of the energy of the atom.
Radium is found in the minerals and ores that contain uranium. In general, one part by weight of radium is found for every 3 million parts of uranium. You can see why it is so rare.
In one ton of high grade ore that is 50 percent uranium, only 150 milligrams of radium will be found. This is about one two hundredth of an ounce.
Pierre Currie was the son of a Paris physician. He taught physics at a college in Paris and did important research on the magnetic properties of metals. The temperature at which these magnetic properties suddenly change is known today as "the Curie point."
Marie Sklodowska came to Paris from Poland to study physics and chemistry and married Perre Currie in 1895. They became interested in the radiations given off by radioactive substances and they worked together in investigating them; this after Antoine Henri Becquerel discovered natural radioactivity in 1896.
In 1903, Pierre and Marie Curie, along with Becquerel, recieved the 1903 Nobel prize for physics.
After that, Pierre Curie received a professorship at the Sorbonne in Paris. When he died in 1906, Marie Curie was appointed to succeed him.
In 1911, Marie Curie received the Nobel prize for chemistry for her work on the isolation of radium and polonium, and for her investigations of their chemical properties.
Marie Curie was instrumental in founding the Radium Institute in Paris and became its first director. During World War I, she took a mobil radiographic unit to the battle front, where she was accompanied by her eldest daughter, 17 year old Irene, who acted as a nurse.
The gamma rays given off by radium have proved extremely useful in treating certain forms of cancer, tumors and skin disorders.
Radium is kept in sealed glass or metal tubes that are often very small. In shipping, the tubes of radium are enclosed in heavy walled tubes of lead to protect persons handling them.