The Discovery of Radioactivity

The discovery of radioactivity happened in 1896 when scientist Henri Becquerel observed that uranium salts emitted a type of invisible energy without any external source of energy like sunlight. This energy could pass through materials and expose photographic plates, revealing an unexpected form of atomic behavior. Marie and Pierre Curie later studied this phenomenon, coining the term "radioactivity." Their work showed that certain elements naturally release energy from their atoms, which was a groundbreaking insight into atomic structure and led to advancements in medicine, energy, and scientific understanding of matter.