Write the redox reaction of the formation of the following compounds: CaO, NaCi, BaO, K2S

Let’s give the names of the substances and compose the equations:
2Ca + O2 = 2CaO;
Ca – 2e = Ca2 + | 2 reducing agent;
2O + 4e = 2O2- | 1 oxidant;
oxygen check: 2 = 2;
2Na + CL2 = 2 NaCL;
Na – e = Na + | 2 reducing agent;
2СL + 2e = 2CL- | 1 oxidizing agent;
2Ba + O2 = 2BaO;
Ba – 2e = Ba2 + | 2 reducing agent;
4O + 4e = 2O2- | 1 oxidizing agent;
2K + S = K2S;
K – e = K + | 2 reducing agent;
S + 2e = S2- | 1 oxidizing agent.
Reactions take place due to the movement of electrons. The role of reducing agents is played by metals: Ca, Na, Ba, K. Oxidizing agents are non-metals O2, CL2, S.