Q. An ancient piece of wood shows an activity of $7.8$ disintegration per second, per gram of $\_{}^{14}C.$ What is the age of piece of the wood if fresh $\_{}^{14}C,$ shows an activity of $31.2$ disintegration per second per gram? Half life of $\_{}^{14}C$ is $5570$ years.
NTA AbhyasNTA Abhyas 2020
Solution: