\(U ^{238}\) has a mass number
(proton \(92+\) neutron \(146\)) \(=238\)
\(U ^{235}\) has mass number (proton \(92+\) neutron \(143)\) \(=235\)
Hence we can say that both contain the same number of protons and electrons
but \(U ^{238}\) contains three more neutrons than \(U ^{235}\)
[Given : $\mathrm{M}(\mathrm{Li})=6.01690\ \mathrm{amu} . \mathrm{M}\left({ }_1 \mathrm{H}^2\right)=2.01471 \ amu.$ $\mathrm{M}\left({ }_2 \mathrm{He}^4\right)=4.00388\ \mathrm{amu}$,$ and\ $$1 \ \mathrm{amu}=931.5$ $\mathrm{MeV}]$