List of top Physics Questions on Decay Rate asked in KEAM

\( 75\% \) of \( ^{234}_{90}\text{Th} \) decays in \( t \) years. Its half-life is (in years):

A radioactive element with $6\times10^{5}$ atoms initially is left with $0.75\times10^{5}$ undecayed atoms in $48$ years. The half-life is:

If N is the initial number of atoms in a radioactive sample, then the number of atoms decayed after the five half life periods is

Eight grams of Cu$^{66}$ undergoes radioactive decay and after 15 minutes only 1 g remains. The half-life, in minutes, is then}

A radioactive sample contains \(10^{-3}\,kg\) each of two nuclear species A and B with half-life 4 days and 8 days respectively. The ratio of the amounts of A and B after 16 days is

The half-life of a radioactive substance is 20 minutes. The time taken between 50% decay and 87.5% decay of the substance will be

The half-life of a radioactive substance is 20 minutes. The time taken between 50% decay and 87.5% decay of the substance will be

The half-life of a radioactive substance is 20 minutes. The time taken between 50% decay and 87.5% decay of the substance will be