A radioactive sample has half-life of 5 years. The percentage of fraction decayed in 10 years will be

Step-by-step solution

Given half-life T_ 1/2 = 5 years and time t = 10 years. Number of half-lives n = t T_ 1/2 = 10 5 = 2 Fraction of sample remaining after n half-lives is given by N N₀ = ( 1 2 )^n N N₀ = ( 1 2 )^2 = 1 4 Fraction of sample decayed = 1 - N N₀ = 1 - 1 4 = 3 4 Percentage of fraction decayed = 3 4 100 % = 75 % Answer: 75 %