For a radioactive sample of half life 1 hour, probability of decay of an active nucleus in 2 hours in percentage is . (Write upto two digits after the decimal point.)
The probability of a radioactive atom decaying within its half life is 50%.
Probability of not decaying in 1 hour = 0.5
Probability of not decaying in another 1 hour = 0.5
Therefore, the total probability of not decaying in 2 hrs =0.5×0.5
So, probability of decaying in two hours = (100−25)%=75%