1. know what elements make up water and in what proportions 2. know why water is pilar and where the poles are 3. know what ph scare measures and how to use the scale to determine ph can someone answer all these for me? i really need

Identify the balanced chemical equation that represents a decomposition reaction. p4 + 3o2 ⟶ p2o3 2fe(oh)3 ⟶ 2feo3 + h2o cuso4 ⟶ cuo + 2so3 2fe(oh)3 ⟶ fe2o3 + 3h2o

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3