Phyllis Lowe, age 11, of Vancouver, B.C., Canada for her question:

WHEN WAS RADIUM FIRST EXTRACTED FROM PITCHBLENDE?

Some people date our atomic age from July 16, 1945, when the first A bomb was exploded in New Mexico. Actually it began much earlier, maybe with the discovery of X rays in 1895. This led indirectly to the discovery of radium and other radioactive materials in pitchblende  which led step by step to the first A bomb.

In 1896 Henri Becquerel of France noticed that uraniumgives off mysterious rays of energy. In those days, the popular topics were bicycles and the newly discovered X rays. The young Curies often rode their bikes through the French countryside, enjoying picnics and admiring the wildflowers. Pierre was a professor of physics, his wife Marie was a talented physics student, very interested in X rays and especially in those strange uranium emissions.

In those days female physics students were not stylish, but this did not bother the Curies. They soon discovered that a uranium ore called pitchblende gives off four times more of those strange emissions. Marie decided to probe this secret, and Pierre took time off to work on her pitchblende project.

They suspected that the mineral compound contained some mysterious, highly energetic substance, perhaps in very small amounts. They used a chemical process called precipitation, which separated all the known elements until only the unknown remained.

Samples of pitchblende were ground up, dissolved and precipitated, boiled, separated and purified time after time. After almost four years of this patient toil, they managed to reduce eight tons of pitchblende to a few thimblefuls of radioactive solution.

But this masterpiece of scientific research was not complete until at least some of the final solution could be isolated and identified as a newly discovered element. In 1898 the Curies announced that they had extracted radium from pitchblende. They also isolated polonium, a second radioactive element, and named for Poland, Marie Curie's homeland.

In 1903 Marie Curie offered her thesis, Researches on Radioactive Substances, to the University of Paris. She was awarded the title of doctor of physical science and became the first female student in Europe to receive a doctorate degree. In the same year, she shared the Nobel Prize for physics with Pierre Curie and Henri Becquerel.