Units of radioactivity

The unit of radioactivity is called the **becquerel (Bq)**. One becquerel is defined as one disintegration (or decay) per second. In addition to the becquerel, other units have historically been used, including the **curie (Ci)**, where 1 curie is equivalent to 3.7 × 10^10 disintegrations per second.

The rutherford (symbol: Rd) is a unit of radioactivity that is used to measure the activity of radioactive isotopes. Specifically, one rutherford is defined as a decay rate of one million disintegrations per second, or \(10^6\) disintegrations per second.