The half-life of a radioactive substance against `alpha-`decay is `1.2 xx 10^7 s`. What is the decay rate for `4 xx 10^15` atoms of the substance ?

The half -life of a radioactive substance is 1.192 xx 10^(7) s against alpha- decay. Calculate the decay rate for 3.18 xx 10^(15) atoms of the substance

The half life of radioactive substance is 1.1xx10^7 s. What is the decay rate for 4.4xx10^15 atoms of the substance ?

The half life of a radioactive substance is 13 years. The decay constant is

The half life of "_92^238U against alpha-decay is 1.5 xx 10^17s . What is the activity of a sample of "_92^238U having 25 xx 10^20 atoms?