Which of the following can penetrate through an aluminum sheet of $20 \, cm$ thickness?

$A$ radioactive element forms its own isotope after $3$ consecutive disintegrations. The particles emitted are

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.

What does the nuclear reaction $_z{X^A} \to {_{z + 1}}{Y^A} + {_{ - 1}}{e^0} + \bar \nu$ represent?

Alpha rays emitted from a radioactive substance are

$A$ radioactive decay can form an isotope of the original nucleus with the emission of which particles?