1. Solid copper reacts with solid sulfur to form solid copper(I) sulfide.2. Nitrogen monoxide gas reacts with hydrogen gas to form ammonia gas and water vapor.3. Solid iron(III) oxide reacts with carbon monoxide gas to form solid iron and carbon dioxide gas.

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.