So here we have a summary of the reactions with oxides, peroxides and superoxides. Oxides are O2- when dealing with group 1A. Remember group 1A metals are plus one. Oxide is 2 minus like we have here. The numbers are different so one comes here and two comes here. So this would be M2O solid. To balance it, I'd have to throw a 2 here and a four here.
When reacting with group 2A we have M2+ because group two way metals are two plus and then O2-. This would just be MO solid. We put a 2 here and A2 here. Remember looking at the periodic table, our peroxides are what are in these purple pinkish boxes. Peroxides memory tool. One tells me that peroxides are bananas, so that's barium and sodium that make these types of structures.
Group 1A would be again plus one, and then we have O22-, 1 comes here, 2 comes here. So we have M2O2. We put a two year to balance it out, and then we'd have barium, which is the metal technically here, but here we'd say it's M2+O22-. The charges cancel out, and that's how we get MO2.
And then remember, memory Tool 2 Smart Kangaroo reads comics potassium rubidium cessium. They're the ones who make superoxides. So here we'd have M+1 for the group 1A metals, O2-1 charges cancel out and that's how we get MO2 solid. We don't have superoxides for group 2A, at least under normal conditions. We have to do some extraordinary things in order to force this to happen. That's beyond the scope of this course, so don't worry about that.
All right? So just remember how we learn what oxides, peroxides and superoxides are, and then remember your two memory tools to recall who are the peroxides and who are the superoxides. Everything else would just be an oxide.