The particle that possesses half integral spin as
Photon
Pion
Proton
$K-$ meson
The half life of a radioactive substance is $20$ minutes. The approximate time interval $(t_2 - t_1)$ between the time $t_2$ when $\frac{2}{3}$ of it had decayed and time $t_1$ when $\frac{1}{3}$ of it had decayed is ..........$min$
A certain radioactive material can undergo three different types of decay, each with a different decay constant $\lambda_1$, $\lambda_2$ and $\lambda_3$ . Then the effective decay constant is
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 $t_{1/2} = 5760\,years$ )
Which is the correct expression for half-life
A radioactive substance has an average life of $5$ hours. In a time of $5$ hours