In a oxidation–reduction reaction, oxidation and reduction must occur simultaneously. Is this statement true or false?

True

Explanation:

Oxidation and reduction always occur simultaneously. Gave example when a substance is oxidized or reduced? 1) The substance gaining oxygen or losing electron is oxidized. 2) The substance losing oxygen ( or gaining electron) is reduced. hope this helps you :)

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.