The order of a radioactive disintegration reaction is:

$A$ certain nuclide has a half-life of $25 \ min$. If one starts with $100 \ g$ of it,how much of it will remain at the end of $100 \ min$?

The half-life of a radioisotope is $4 \ h$. If the initial mass of the isotope was $200 \ g$,the mass remaining after $24 \ h$ undecayed is ........... $g$.

The half-life of $_{92}U^{238}$ is $4.5 \times 10^9$ years. After how many years,the amount of $_{92}U^{238}$ will be reduced to half of its present amount?

$A$ radioactive element has a half-life of $200 \ days$. The percentage of original activity remaining after $83 \ days$ is $....$ (Nearest integer).
(Given: $\text{antilog } 0.125 = 1.333$,$\text{antilog } 0.693 = 4.93$)

The half-life period of $Pb^{210}$ is $22 \ years$. If $2 \ g$ of $Pb^{210}$ is taken,then after $11 \ years$ how much of $Pb^{210}$ will be left in $g$?