If the fraction of the atoms of a radioactive material left after 120years is 1/64; what is the half-life of the material? 1/64 by Sunday | Nov 1 | Physics JAMB | 0 comments A. 20 years B. 10 years C. 2 years D. 24 years Correct Answer: Option A – 20 years Users Also Read These:A radioactive substance has a half-life of 20 days…If 100 atoms of element X contains 70 atoms of 9X…An element whose half-life is 3 years has N atoms.…A radioactive element has a half life of 4 days. The…In 24 days a radioactive isotope decreases in mass…