If $2.0 \ g$ of a radioactive substance has a half-life of $7 \ days$,what is the half-life of a $1 \ g$ sample?

$1.0 \, g$ of a radioactive isotope was found to reduce to $125 \, mg$ after $24 \, hours$. The half-life of the isotope is $....... \, hours$.

The half-life of a radioisotope is $4 \ hours$. If the initial mass of the isotope is $200 \ g$,then the mass remaining after $24 \ hours$ will be ....... $g$.

$10 \ g$ of a radioactive element is disintegrated to $1 \ g$ in $2.303 \ \text{minutes}$. What is the half-life (in minutes) of that radioactive element?

The half-life for decay of ${}^{14}C$ by $\beta$-emission is $5730 \ yr$. The fraction of ${}^{14}C$ that decays in a sample that is $22920 \ yr$ old would be

The half-life period of a radioactive substance is $8 \ years$. After $16 \ years$,the mass of the substance will reduce from starting $16.0 \ g$ to ....... $g$.