The mass defect (ΔM) for a nucleus of mass number (A), atomic number (Z) and mass (M) is given by
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → $ΔM = [Z m_p + (A - Z) m_n] - M$
Mass defect is given by:
$\Delta M = [Z m_p + (A - Z) m_n - M]$
where,
$m_p$ = mass of proton
$m_n$ = mass of neutron
$M$ = actual mass of nucleus
$A$ = mass number
$Z$ = atomic number