Maria Skłodowska's contribution to science is great and universally known. In the early 1820s, she went on her tour of triumph to the US. The US President presented her with a gift, which was purchased with money raised especially by American ladies. Maria was shocked – the gift was one gram of radium, the element that Maria and Pierre Curie discovered.

Once radioactivity was discovered by Henri Becquerel in 1896, Maria Curie started her research of radioactive materials. Soon she found out that a uranium ore called uraninite electrified the surrounding air much more than the uranium and thorium compounds therein. Maria Curie concluded that the uranium ore contained an unknown, highly radioactive element. Even two elements, as it turned out. She named one of the elements polonium (after her native Poland) and the other one – radium. Having realized the importance of his wife's discoveries, Pierre Curie joined her. Without a laboratory, working literally in a shed, the couple washed tons of uranium ore in the next four years and finally extracted enough radium to measure its atomic weight. That discovery did not make them rich. It might have done though – radium is rare in nature, so its price was off the chart. But the Curies refused to patent it or use it commercially as it was against the spirit of science i.e., the principle of free knowledge exchange. However, they were awarded the Nobel Prize, with Maria winning even two – in physics and in chemistry.