Charles Williams, age 14, of Galveston, Tex., for his question:
WHERE DO WE FIND RADIUM?
Radium is a radioactive metallic chemical element that can be found in uranium. Small deposits of uranium ore have been found in many places in various parts of the earth.
The chief source of uranium, and therefore radium, is the ore called pitchblende. Deposits of pitchblende have been found in Cornwall, England; in Zaire in Africa; in the Great Bear Lake area of Canada; and in the form of carnotite in Utah and Colorado. Carnotite is a binder between sand particles.
For years the deposits in Zaire, then called the Belgian Congo, were the most productive in the world. But then in 1930 the Canadian sources were discovered. One of the world's largest deposits was found in the Blind River area in Ontario and Canada has become one of the leading producers of uranium.
Since 1940 uranium ore has become more important for its uranium content than for its radium. This is because uranium is needed for the nuclear energy programs of many countries. The United States is a leading consumer of uranium.
Radium is a very rare and precious element. But since the 1940s, nuclear reactors have been able to manufacture artificial radioactive materials called radioisotopes, which can sometimes be used instead of radium.
Tae gamma rays given off by radium have been successfully used in treating some types of cancer, tumors and skin diseases.
You can understand radium's nature when you study the makeup of the atom. Atoms are made of electrons, protons and neutrons. Protons and neutrons make up a small but heavy nucleus or core of the atom. Most atoms are stable, which means that their makeup doesn't change from year to year. But a few of the heaviest atoms break down and change into other atoms. This breakdown ox decay is called "radioactivity." Radium is one of the most radioactive of all elements.
Radioactivity was discovered in 1$96 by a French scientist named Henri Becquerel. He found it in the element uranium.
Becquerel found that his uranium, when placed on a photographic plate, made strange tracks as though it had been light struck. He gave the problem of understanding what caused this to a chemistry student, Marie Curie.
Madame Curie and her husband, Pierre, refined some pitchblende, and soon discovered that the uranium itself was giving off invisible rays, but some other substance hidden in the ore was much more powerful.
Their first success came when they discovered the radioactive element polonium, which Marie Curie named for Poland, her native country. The search continued for a substance that was even more powerful.
In 1989 the Curies were able to separate a quarter of a gram of radium.
Radium is naturally radioactive and gives off three kinds of radiation or rays: alpha, beta and gamma. Both alpha and beta rays are actually particles, while the gamma rays are electromagnetic radiation.