1. The SI unit of radioactivity, equal to one nuclear decay per second.
Usage: physics; often abbreviated as Bq; named after physicist Henri Becquerel

Examples

• The radioactive sample had an activity of 500 becquerels.
• Scientists measured the becquerel output of the uranium sample.
• One becquerel equals one disintegration per second.
• The contaminated water showed a becquerel level above safe limits.
• Radiation safety standards are often expressed in becquerels per liter.