Identify the correct expression for the mass defect of a nucleus that contains protons

PHYSICS · Single correct · A Level · Physics · Nuclear physics · Nuclear physics

Problem

Identify the correct expression for the mass defect

\Delta m

of a nucleus that contains

Z

protons,

N

neutrons and has rest mass

m_{\text{nucleus}}

. (a)

\Delta m = (Z+N)m_n - m_{\text{nucleus}}

(b)

\Delta m = Nm_p + Zm_n - m_{\text{nucleus}}

(c)

\Delta m = Zm_p + Nm_n - m_{\text{nucleus}}

(d)

\Delta m = m_{\text{nucleus}} - Zm_p - Nm_n