Define average life of a radioactive substance. Obtain the relation between decay constant and average life.

In one averge life - time of a radioactive nuclei,

Define half - life of a reaction.

Define half life period and decay constant for a radioactive substance. Deduce the relation between them.

Half-life of a radioactive substance is 18 minutes. The time interval between its 20% decay and 80% decay in minutes is

The ratio of molecular mass of two radioactive substances is 3/2 and the ratio of their decay constant is 4/3 . Then find the ratio of their initial activity per mole

Half-life of a radioactive substance A is 4 days. Find the probability that a nucleus will decay in two half- life