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 $t_{1/2} = 5760\,years$ )
$1672$
$2391$
$3291$
$4453$
If $t_{1/2}$ is the half life of a substance then $t_{3/4}$ is the time in which substance
The radioactivity of a sample is $R_1$ at time $T_1$ and $R_2$ at time $T_2.$ If the half life of the specimen is $T.$ Number of atoms that have disintegrated in time $(T_2 - T_1)$ is proportional to
If half life of radium is $77$ days. Its decay constant in day will be
The decay constant of a radio active substance is $0.173\, (years)^{-1}.$ Therefore :
A radioactive element emits $200$ particles per second. After three hours $25$ particles per second are emitted. The half life period of element will be ..........$minntes$