What is meant by activity or decay rate? Give its unit.

Explanation

(i) Activity ( R) or decay rate which is defined as the number of nuclei decayed per second and it is denoted as
`R=|(dN)/(dt)|`
(ii) The SI unit of activity R is Becquerel and one Becquerel (Bq) is equal to one decay per second. Another standard unit for the activity called Curie(Ci). 1 Curie = 1
Ci = `3.7xx10^(10)` decays per second
1 Ci = `3.7xx10^(10)` Bq.