The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the binding energy per nucleon (in J) of a nucleus? (The mass of a cobalt- 60 nucleus is 59.9338 amu.)

Question

The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the binding energy per nucleon (in J) of a  nucleus? (The mass of a cobalt- 60 nucleus is 59.9338 amu.)

Quizplus · Accepted Answer

The total mass of a 11ec8354_ee08_ac0f_b7a5_cd0950e15023_TB1819_11 nucleus is (11)(1.00728 amu) + (23)(1.00867 amu) = 27.90869 amu.
The mass defect is (27.90869 amu) - (59.9338 amu) = 32.02511 amu.
The binding energy is (32.02511 amu)(1.66054 x 10^-27 kg/amu)(2.99792 x 10^8 m/s)^2 = 4.806 x 10^-10 J
The number of nucleons in a 11ec8354_ee08_ac0f_b7a5_cd0950e15023_TB1819_11 nucleus is 34, so the binding energy per nucleon is (4.806 x 10^-10 J)/(34 nucleons) = 1.415 x 10^-11 J/nucleon
The closest answer is C) 1.368 × 10^-11 J/nucleon.

The Mass of a Proton Is 1