(C) 2, 2, 4
Balanced equation: 2 Zn(NO₃)₂ → 2 ZnO + 4 NO₂ + O₂. Here x = 2, y = 2, z = 4.
Balance each element: LHS has 2 Zn, 4 N, 12 O. RHS: 2 ZnO (2 Zn, 2 O) + 4 NO₂ (4 N, 8 O) + O₂ (2 O) = 2 Zn, 4 N, 12 O. ✓ The hit-and-trial method from Chapter 1 is used here. Note option (C) gives the smallest whole-number coefficients that satisfy conservation of mass.