Half life of radium is $1620$ years. How many radium nuclei decay in $5$ hours in $5\, gm$ radium? ( Atomic weight of radium $= 223$)
$9.1 \times 10^{12}$
$3.23 \times 10^{15}$
$1.72 \times 10^{20}$
$3.3 \times 10^{17}$
Two radioactive materials $A$ and $B$ have decay constant $5\lambda$ and $\lambda$ respectively.At $t=0$ they have the same number of nuclei, then the ratio of the number of nuclei of $A$ to that $B$ will be $(1/e)^2$ after a time interval
Write the law of radioactive decay.
At time $t = 0, N_1$ nuclei of decay constant $\lambda _1 \,\& \,N_2$ nuclei of decay constant $\lambda _2$ are mixed . The decay rate of the mixture is :
Half life period of a sample is $15$ years. How long will it take to decay $96.875\%$ of sample .......... $years$
Decay constant of radium is $\lambda $. By a suitable process its compound radium bromide is obtained. The decay constant of radium bromide will be