Question

Half life of a radioactive substance A is 4 day.s The probability that a nucleus will decay in two half lives is

(1) 1/4

(2) 3/4

(3) 1/16

(4) 1

Answer 1

Correct option : (2) 3/4

Explanation :

After two half lives (1/4)^th  fraction of nuclei will remain unchanged. Hence (3/4)^th fraction will decay. Hence the probability that a nucleus decays in two half lives is 3/4.