Question

(²³⁵₉₂U + ¹₀n → 144₅₆Ba + ⁸⁹₃₆kr + ¹₀n +energy)

(Give full credit for any other one correct example.)

Answer 1

The number are conserved but the total mass is nor conserved. 

The total mass of the free protons/neutrons is more than their total mass within the nucleus. The lost mass (= Δm), gets converted into energy as per the relation.   E = (Δ  m)c²

[Also, accept alternative ways of explaining the phenomenon]