Becquerel

The becquerel (abbreviation Bq) is the SI derived unit of radioactivity, defined as the activity of a quantity of radioactive material in which one nucleus decays per second. It is therefore equivalent to s^-1. The older unit of radioactivity was the curie (Ci). 1 Bq = 2.7×10^-11 Ci.

It was named after Henri Becquerel, who shared a Nobel Prize with Marie Curie for their work in discovering radioactivity.