Which scientist is associated with pioneering work on radioactivity and with coining the term "radioactivity"?

• A. Henri Becquerel
• B. Albert Einstein
• C. Marie Curie
• D. Isaac Newton

Answer: (C)

The question tests who both helped pioneer the study of radioactivity and coined the actual term for it. Marie Curie fits best because her groundbreaking work expanded the understanding of radioactive phenomena and, in 1898, she introduced the word “radioactivity” to describe the spontaneous emission of radiation from unstable atomic nuclei. Her careful experiments with pitchblende led to the discovery of new elements like polonium and radium and laid the foundation for the field. While Henri Becquerel first observed that certain materials emit radiation, he did not coin the term. Einstein contributed important theoretical ideas about radiation, but he wasn’t the one who named the phenomenon. Newton is from a much earlier era and isn’t connected to radioactivity.