How many electrons does 0^2- have ? Please explain how that is the answer

Which substance can be broken down by chemical means

Match each term to its description. match term definition excess reactant a) reactant that can produce a lesser amount of the product limiting reactant b) amount of product predicted to be produced by the given reactants theoretical yield c) reactant that can produce more of the product

How many ammonium ions and how many sulfate ions are present in a 0.270 mol sample of ?