Marie Curie was born in Warsaw, Poland. Her first name was Maria. As a teenager, she made a pact with her sister. Marie would help support her sister's medical studies in Paris. Then her sister would help pay for Marie's studies. Marie worked for years as a governess and tutor. Only then could she study at the Sorbonne in Paris. There, she began to use the French name Marie. She felt unprepared. She worked hard to catch up.

In 1893, Marie finished first in her physics degree. In 1894, she finished second in math. That year, she met Pierre Curie. They married in 1895. In 1896, Henri Becquerel found that uranium gives off rays. Marie began to study these rays. She found that the strength of the rays depended only on how much uranium was present. Compounds of thorium also gave off rays. Marie invented a new word for this: radioactivity.

Next, Marie tested a mineral called pitchblende. It was more radioactive than uranium. So the Curies decided that it must hold other new elements. They found polonium and radium. The name radium comes from the Latin word for ray. Marie named polonium after Poland, the country where she was born. To separate radium, she had to treat very large amounts of pitchblende ore. Much of the work took place in a shed.

In 1910, Marie produced radium as a pure metal. The Curies published how they isolated it. They did not patent their methods. In 1903, Marie shared the Nobel Prize in Physics with Pierre and Henri Becquerel. She was the first woman to win a Nobel Prize. In 1911, she won a second Nobel Prize, in chemistry. She was the first person to win two. In 1906, she became the first woman to hold a professor's post at the Sorbonne.

In World War I, Marie organized mobile X-ray teams. She learned to drive a car so she could run the X-ray cars herself. The cars were nicknamed petites Curies, French for little Curies. X-rays helped doctors find bullets and broken bones in wounded soldiers. In 1921, the women of America gave Marie one gram of radium. In 1929, on her second American tour, she succeeded in equipping the Warsaw Radium Institute with radium.

Words to know

• governess: a live-in teacher
• radioactivity: rays from atoms
• pitchblende: a uranium ore
• patent: a legal claim
• isolated: separated out