Question Detail
Question
Find the mass defect of 63Cu if the actual mass of copper is 62.91367u. Given rest mass of proton = 1.007276 u, rest mass of neutron = 1.008665 u, and rest mass of Hydrogen atom = 1.007825 u. (Atomic number of Cu is 29).
Correct Answer
Option C is the correct answer.
Detailed Explanation
The mass defect is the difference between the total mass of the individual nucleons (protons and neutrons) and the actual mass of the nucleus.For Copper-63 (63Cu):Atomic number (Z) = 29 (number of protons)Mass number (A) = 63Number of neutrons (N) = A - Z = 63 - 29 = 34Total mass of 29 protons = 29 * 1.007276 u = 29.211004 uTotal mass of 34 neutrons = 34 * 1.008665 u = 34.29461 uTotal mass of constituent nucleons = 29.211004 u + 34.29461 u = 63.505614 uActual mass of 63Cu = 62.91367 uMass defect = (Total mass of constituent nucleons) - (Actual mass of 63Cu)Mass defect = 63.505614 u - 62.91367 u = 0.591944 uRounding to the nearest option, 0.59223u is the closest.
Hint
The mass defect is the difference between the sum of the masses of individual protons and neutrons and the actual atomic mass. Remember to count the number of protons and neutrons in the nucleus.