Based on the enthalpy changes given for the reactions, which reactions are endothermic? (check all that apply)

2H2O → 2H2 + O2, ΔH = 484 kJ

C + O2 → CO2, ΔH = -394

kJ H2 + Br2 → 2HBr, ΔH = -73

kJ 2NH3 → N2 + 3H2, ΔH = 92 kJ