Chemistry

Problem

A slow neutron is captured by a

^{235}_{\,92}\mathrm{U}

nucleus, leading to the fission reaction

^{235}_{\,92}\mathrm{U}+^{1}_{\,0}n\;\longrightarrow\;^{93}_{\,36}\mathrm{Kr}+X+3\,^{1}_{\,0}n

. Which nuclide must

X

be for the reaction to satisfy conservation laws? a)

^{140}_{\,55}\mathrm{Cs}

^{143}_{\,56}\mathrm{Ba}

^{140}_{\,56}\mathrm{Ba}

^{137}_{\,54}\mathrm{Xe}