Calculate the decay constant for `Ag^(108)` if its half life is 2.31 minutes.

What will be the rate constant of a I order reaction, if its half life is given to be 20 min ?

On your birthday, you measure the activity of the sample ""^(210)Bi which has a half - life of 5.01 days. The initial activity that you measure is 1muCi . (a) What is the approximate activity of the sample on your next birthday? Calculate (b) the decay constant (c) the mean life (d) initial number of atoms.

The half-life of .^198Au is 2.7 days . Calculate (a) the decay constant, (b) the average-life and (c) the activity of 1.00 mg of .^198Au . Take atomic weight of .^198Au to be 198 g mol^(-1) .

Counting rate from a radioactive source is 8000 cts per sec. at time t = 0 and after 10 minutes decay is 1000 cts/sce. Calculate (i) half life period, (ii) decay constant and (iii) counting rate after 20 minutes.

Half lives of two radioactive elements A and B are 20 minutes and 40 minutes respectively. Initially, the samples have equal number of nuclei. Calculate the ratio of decayed numbers of A and B nuclei after 80 minutes.