A radio-active sample of half-life ( 10 ) days contains ( 1000 ) nuclei. Number of original nuclei present after ( 5 ) days is

Step-by-step solution

Given, half-life, ( T_ 1 / 2 =10 ) days; ( N₀=1000 x ; t=5 ) days Now, ( t= 1 2 T_ 1 2 =n T_ 1 2 ) ( n= 1 2 ) ( N= N₀ 2^ n = 1000 x 2^ 1 / 2 = 1000 x 1.414 =707.21 x ) Therefore, number of original nuclei present after ( 5 ) days is ( 707.21 x 707 x )