Half-life period of a radiactive substance is 10 min , then amount of substance decayed in 40 min will be

Step-by-step solution

Number of half-lives in 40 min n= 40 T_ 1 / 2 = 40 10 =4 Amount of the substance remaining after n half- lives N=N₀ ( 1 2 )^n=N₀ ( 1 2 )^4= N₀ 16 where, N₀ is original amount of the substance. Amount of the substance decayed in 40 min . N^ =N₀-N=N₀- N₀ 16 = 15 16 N₀= ( 15 16 100 % ) of N₀=15 6.25 % of N₀=93.75 % of N₀