An atomic nucleus $_{90}^{232}Th$ emits several $\alpha$ and $\beta$ radiations and finally reduces to $_{82}^{208}Pb$. It must have emitted:

If a heavy nucleus has an $N/Z$ ratio higher than that required for stability,then:

Sometimes a radioactive nucleus decays into a nucleus which itself is radioactive. An example is
$^{38}S \xrightarrow{2.48 \ h} ^{38}Cl \xrightarrow{0.62 \ h} ^{38}Ar$
Assume that we start with $1000$ $^{38}S$ nuclei at time $t = 0$. The number of $^{38}Cl$ nuclei is zero at $t = 0$ and will again be zero at $t = \infty$. At what value of $t$ would the number of $^{38}Cl$ nuclei be a maximum?

Which of the following nuclear reactions is possible?

In a radioactive decay chain reaction,${ }_{90}^{230} Th$ nucleus decays into ${ }_{84}^{214} Po$ nucleus. The ratio of the number of $\alpha$ to number of $\beta^{-}$ particles emitted in this process is. . . . .

Arrange the radioactive radiations in increasing order of their ionizing power and penetrating power.