A piece of bone of an animal from a ruin is found to have $^{14}C$ activity of $12$ disintegrations per minute per gm of its carbon content. The $^{14}C$ activity of a living animal is $16$ disintegrations per minute per gm. How long ago nearly did the animal die? ............$years$ (Given halflife of $^{14}C$ is $t_{1/2} = 5760\,years$ )

The half life of a radioactive isotope $'X'$ is $20$ years, It decays to another element $'Y'$ which is stable. The two elements $'X'$ and $'Y'$ were found to be in  the ratio $1:7$ in a simple of a given rock . The age of the rock is estimated to be............$years$

$1 \,mg$ gold undergoes decay with $2.7$ days half-life period, amount left after $8.1$ days is ......... $mg$

Which of the following is not a mode of radioactive decay

A radioactive nucleus (initial mass number $A$ and atomic number $Z$ emits $3 \alpha$. - particles and $2$ positrons. The ratio of number of neutrons to that of protons in the final nucleus will be

What can be found from decay curve ?