What did Marie Curie discover?

Marie Curie carried out research in the field of radioactivity. She was twice awarded a Nobel Prize! At the time in which she lived, it was very unusual for a woman to do scientific work and to become a professor (at the Sorbonne, in Paris). 

Chemistry
Marie was born in Poland in 1867 (her maiden name was Sklodowska). Growing up, she always wanted to study chemistry. For that reason she moved to Paris, which is where she met her future husband, Pierre Curie.

Radioactivity
After graduating from university, she started doing research into radioactivity. It had only just been discovered. For this work, Marie was awarded the Nobel Prize for physics, together with her husband Pierre. Later, she also discovered two radioactive substances – radium and polonium. In 1934, Marie Curie died of leukaemia, which was probably caused by her frequent exposure to radiation during her work.