The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the mass defect (in amu)of a Ni nucleus? (The mass of a nickel-60 nucleus is 59.9308 amu.)

Question

The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the mass defect (in amu)of a  Ni nucleus? (The mass of a nickel-60 nucleus is 59.9308 amu.)

Quizplus · Accepted Answer

The mass defect of the nucleus can be calculated through the formula:
mass defect = (mass of protons + mass of neutrons - mass of nucleus)

The mass of protons in the nucleus = (28 protons) x (1.00728 amu/proton) = 28.19824 amu
The mass of neutrons in the nucleus = (32 neutrons) x (1.00867 amu/neutron) = 32.27544 amu
The total mass of protons and neutrons in the nucleus = 60.47368 amu

Mass defect = (28.19824 amu + 32.27544 amu - 59.9308 amu)
Mass defect = 0.54288 amu

Therefore, the mass defect of the nickel-60 nucleus is 0.54288 amu. The closest answer choice to this value is C) 0.5491 amu, which is the best choice.

The Mass of a Proton Is 1