1)name of the building block of all matter. 2)which of the following is tetraatomic molecule CH3OH,CH4,H2O3?. 3)an element X of valency 3 combines with another Y of valency 2.what will be the formula of the compound formed ,give reason. 4)give to example of trivalent metal ions. 5)what do the symbols , H2,S and O4 means in the formula H2SO4?.