Question

If mass of `U^(235)=235.12142 a.m.u.`, mass of `U^(236) =236.1205 amu`, and mass of neutron `=1.008665 am u`, then the energy required to remove one neutron from the nucleus of `U^(236)` is nearly about.
A. `75 MeV`
B. `6.5 MeV`
C. `1 eV`
D. zero

Answer 1

Correct Answer - b
Mass of one atom of `U.^(235)` is `235.121420 a.m.u.`
Mass of one neutron `=1.008665 a.m.u.`
Sum of the masses of `U.^(235)` and neutron
`=236. 130085 =236.130 a.m.u.`
Mass of one of `U.^(236)` is
`236.123050 a.m.u.` `=236.123 a.m.u.`
Mass defect `=236.136 -236.123`
`=0.007a.m.u.`
Therefore, enregy required to remove one neutron is
`0.007 xx 931 MeV=6.517 MeV=6.5MeV`.