The half life of polonium is $140\, days$. After how many days, $16 \,gm$ polonium will be reduced to $1 \,gm$ .........$days$(or $15\,g$ will decay)
$700$
$280 $
$560 $
$420$
The activity of a radioactive sample is $1.6\, curie$ and its half-life is $2.5 \,days$. Its activity after $10\, days$ will be .......... $curie$
Carbon $ - 14$ decays with half-life of about $5,800\, years$. In a sample of bone, the ratio of carbon $ - 14$ to carbon $ - 12$ is found to be $\frac{1}{4}$ of what it is in free air. This bone may belong to a period about $x$ centuries ago, where $x$ is nearest to
The half life period of radium is $1600$ years. The fraction of a sample of radium that would remain after $6400$ years is
The fraction $f$ of radioactive material that has decayed in time $t$, varies with time $t$. The correct variation is given by the curve
A sample contains $10^{-2}\, kg$ each of two substances A and $B$ with half lives $4 \,s$ and $8 \,s$ respectively. The ratio of then atomic weights is $1: 2$ The ratio of the amounts of $A$ and $B$ after $16 \,s$ is $\frac{x}{100}$. the value of $x$ is........