Question

Consider a radioactive element with the nucleus 'X' having the atomic number A and the mass number Z. It emits an α particle. The change thus happens from the parent nucleus X to the daughter nucleus Y can be expressed as:

$\underset{\text{Parent nucleus}}{{}_Z^{A}X}\to \underset{\text{Daughter nucleus}}{{}_{Z-4}^{A-2}Y}+\underset{(\alpha -\text{particle})}{{}_2^{4}He}$

• A. True
• B. False

Answer 1

The correct option is B

False

Here, the radioactive element with the nucleus 'X' having the atomic number Z and the mass number A is considered. As it undergoes α emission, the atomic number of the daughter nucleus becomes (Z-2) and the mass number becomes (A-4). Thus the resulting nucleus has 2 protons and 2 neutrons(totally 4 nucleons) less than the parent nucleus. The change thus happens from the parent nucleus X to the daughter nucleus Y can be expressed as:

$\underset{\text{Parent nucleus}}{{}_Z^{A}X}\to \underset{\text{Daughter nucleus}}{{}_{Z-2}^{A-4}Y}+\underset{(\alpha -\text{particle})}{{}_2^{4}He}$

So, the given statement is false.