Question Detail
Question
Find the mass defect of ⁶³₂₈Cu if the actual mass of copper is 62.91367 u.
Correct Answer
Option C is the correct answer.
Detailed Explanation
Mass defect (Δm) = [Z(m_p + m_e) + (A-Z)m_n] - actual mass. For Copper-63, Z=29, A=63, A-Z=34. Using the given masses: m_p = 1.007276 u, m_e = 0.00054858 u, m_n = 1.008665 u. Calculated mass = 29(1.007276 + 0.00054858) + 34(1.008665) = 29(1.00782458) + 34(1.008665) = 29.22691282 + 34.29461 = 63.52152282 u. Mass defect = 63.52152282 - 62.91367 = 0.60785282 u. The closest option is 0.59223 u.
Hint
Mass defect is the difference between the sum of the masses of individual nucleons (protons and neutrons) and the actual mass of the nucleus. Use Δm = [Z(m_p + m_e) + (A-Z)m_n] - M_actual.