Assuming the experimental mass of 612C as 12 u, the mass defect of 612C atom is MeV/c2. (Mass of proton = 1.00727 u, mass of neutron = 1.00866 u, 1 u = 931.5 MeV/c2 and c is the speed of the light in vacuum).
- 127.5
- 89.03
- 272.0
- 92.0
Answer
(2) 89.03
Solution
612C: Z=6 protons, A-Z=6 neutrons
m=6mp+6mn-M
=6(1.00727)+6(1.00866)-12
=6.04362+6.05196-12=0.09558 u
m=0.09558 931.5 MeV/c2
m 89.03 MeV/c2
Answer: (2)