Question

If $m, m_{n}$ and $m_{p}$ are the masses of $z^{X^{A}}$ nucleus, neutron and proton respectively, then:

• A. $m<(A-Z) m_{n}+Z m_{p}$
• B. $m=(A-Z) m_{n}+Z m_{p}$
• C. $m=(A-Z) m_{p}+Z m_{p}$
• D. $m>(A-Z) m_{n}+Z m_{p}$

Answer 1

Answer: (A)

The mass of nucleus formed is always less than the sum of the masses of the constituents protons and neutrons, i-e., $m <( A - Z ) m _{ n }+ Zm _{ p }$