The rate constant for a radioactive decay reaction is $\lambda$. The average life is represented by:

$A$ radioactive isotope having a half-life period of $3 \ days$ was received after $12 \ days$. If $3 \ g$ of the isotope is left in the container,what would be the initial mass of the isotope?.......... $g$

The half-life of a radioactive isotope is $3 \ hours$. If the initial mass of the isotope is $256 \ g$,how much mass in $g$ will remain after $18 \ hours$ (in $.0$)?

If the half-life of a certain radioactive nucleus is $1000 \ s,$ the disintegration constant is

If $n_t$ number of radioatoms are present at time $t$,the following expression will be a constant:

The decay of a radioactive element follows first-order kinetics. As a result: