Question

Explain what percentage of the parent element will decay into the daughter element through the process of radioactive decay during each of the first 3 half lives?

Answer 1

in every half life 50% of nuclei present at that instant undergo decay. so 1 half lives means 50 nuclei have gone if 100 were present. 2nd half life ie 25 gone from 50 present. and in 3rd half life 12.5 gone from 25 present. so in the end 12.5 % of initial no. of nuclei remain.