Answer
$Hg_{80}^{198} + n_{0}^{1} -> Hg_{80}^{199} -> Au_{79}^{198} + p_{1}^{1}$
Work Step by Step
Upon bombardment with neutrons, Mercury-198 is converted into Mercury-199 which then emits a proton.
$Hg_{80}^{198} + n_{0}^{1} -> Hg_{80}^{199} -> Au_{79}^{198} + p_{1}^{1}$
