Question

The isotopes of an element X are ${}_z{X}^A,{}_z{X}^{A+1},{}_z{X}^{A+2}$ respectively. What is the ratio of number of nucleons in these respective isotopes?

• A. A : (A + 1) : (A + 2)
• B. 1 : 1 : 1
• C. (A - Z) : ((A + 1) - Z) : ((A + 2) - Z)
• D. 1 : 2 : 3

Answer 1

The correct option is A

A : (A + 1) : (A + 2)

Nucleons are the particles present inside the nucleus of an atom. Nucleons consists of protons and neutrons. Mass number is the total number of protons and neutrons present in the nucleus. Therefore their ratio is:-
${}_Z{X}^A,{}_Z{X}^{A+1},{}_Z{X}^{A+2}$ is $A:(A+1):(A+2)$