Wht will react with acid to giv bluish green salt nd water ??

Explanation:

When dilute HCl is added to a small amount of copper oxide in a beaker, a greenish-yellow gas is released and a bluish-green solution is formed. Since the metal oxides such as a Copper oxide (CuO) are basic in nature, it reacts with acids such as HCl to form the corresponding salt and water.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.