$${Q = (238,05079\, \mathrm{u})c^2 - (234,04363\, \mathrm{u} + 4,00260\, \mathrm{u})c^2 \\ = (0,00456\, \mathrm{u})c^2 = (0,00456\, \mathrm{u}) (931,494013\, \mathrm{MeV/u}) \\ = \underline{\underline{4,25\, \mathrm{MeV}}}}$$