A becquerel (Bq) is a unit of measurement used to quantify radioactivity. It represents one disintegration or decay of a radioactive atom per second. This unit is named after the French physicist Henri Becquerel, who discovered radioactivity in 1896. Becquerels are commonly used in fields such as nuclear physics, medicine, and environmental science to measure the activity of radioactive materials. For example, a sample with an activity of 1 Bq indicates that one atom is decaying every second, providing a way to assess the level of radiation exposure and its potential health effects.