Who shared the Nobel Prize in 1903 for discoveries related to radioactivity?

The correct answer is Henri Becquerel. He shared the Nobel Prize in Physics in 1903 for his groundbreaking work on radioactivity. Becquerel's experiments with uranium salts demonstrated that they emitted rays that could penetrate opaque materials, which was a significant discovery in the understanding of radioactive elements. This work was foundational and set the stage for further research by scientists like Marie Curie and Pierre Curie, who also contributed to the study of radioactivity and were awarded the Nobel Prize alongside Becquerel in that same year.

Marie Curie is critical to the history of radioactivity as she conducted extensive research on radioactive isotopes and discovered polonium and radium, leading to her own Nobel Prize wins later, but her contributions were not the sole focus of the 1903 award. James Chadwick is known for discovering the neutron in 1932, and Ernest Rutherford is celebrated for his work on the structure of the atom and his own discoveries related to radioactivity, but he was not a recipient of the 1903 Nobel Prize.