Naming the product of simple ionic compounds?

I am doing homework


We have to combine (not litterally) elements like Lithium and Oxygen.





The question is "Classify each reaction ( Formula, Hydra Carbon Combustion, Double or Single Replacement) and write the formula of each product or products"


The first one is Li + O2


I'm terrible at chem.


How do I decide what the little number at the bottom right will be?

Naming the product of simple ionic compounds?
It would be Li2O, and it would be a combustion. Any time O2 is a reactant, it's a combustion reaction.
Reply:No, no, no. Li has a charge of +1, O a charge of minus one, so the product will be Li20. Then, to balance the equation it would be 2Li + O2 yields 2Li20
Reply:i'm not sure how to classify it, but i think the product of Li + O2 would be Li4O2. The charge on one Li is +1, and the charge on one O is -2. 2 Oxygen have a charge of -4, so to balance that you need 4 positive charges, hence 4 Lithium ions. Group1 elements are +1, Group 2 are +2