AP BIOLOGY

Detailed explanation-1: -An ionic bond can be formed after two or more atoms loss or gain electrons to form an ion. Ionic bonds occur between metals, losing electrons, and nonmetals, gaining electrons. Ions with opposite charges will attract one another creating an ionic bond.

Detailed explanation-2: -Ionic compounds are (usually) formed when a metal reacts with a nonmetal (or a polyatomic ion). Covalent compounds are formed when two nonmetals react with each other. Since hydrogen is a nonmetal, binary compounds containing hydrogen are also usually covalent compounds.