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.)

Mass Defect: 0.5505 amu.

A nickel-60 atom contains sixty nucleons (neutrons and protons).

According to the question,

Mass of the 60 nucleons shall add up to .

The mass defect of a nucleus is "the difference between the sum of masses of [its] components and [its] measured [mass]." ("Map: A Molecular Approach (Tro)", Chemistry Libretexts)

According to the question, the measured mass of a nickel-60 nucleus is 59.9308 amu.

The difference between the sum of the masses of its nucleon components and the mass of its nucleus is, therefore, (accurate to four decimal places.)

the answer is a! (2.9 x 10^-18 j) hope i could someone. : )