Which of the following can pass through $20 \, cm$ thickness of steel?

In the given nuclear reaction,how many $\alpha$ and $\beta$ particles are emitted in the decay $_{92}X^{235} \to _{82}Y^{207}$?

What is the respective number of $\alpha$ and $\beta$ particles emitted in the following radioactive decay: $_{90}X^{200} \to _{80}Y^{168}$?

Consider a radioactive nucleus $A$ which decays to a stable nucleus $C$ through the following sequence: $A \to B \to C$. Here $B$ is an intermediate nucleus which is also radioactive. Considering that there are $N_0$ atoms of $A$ initially,plot the graph showing the variation of the number of atoms of $A$ and $B$ versus time.

When a radioactive isotope ${}_{88}^{228}Ra$ decays in series by the emission of $3$ alpha particles and $1$ beta particle,the isotope finally formed is

$A$ radioactive nucleus emits $4 \alpha$ particles and $7 \beta$ particles in succession. The ratio of the number of neutrons to that of protons in the final nucleus is $[A = \text{mass number}, Z = \text{atomic number}]$