3.2 Covalent Compounds

Formulas and Basics

Covalent compounds are compounds composed of two or more nonmetals or metalloids that share electrons in their bonds to attain a full valence electron shell. Unlike ionic compounds, which transfer electrons, covalent compounds share the same electrons between atoms to fill both atoms’ valence shells at once. Covalent compounds can be formed in many different ratios with the same atoms unlike ionic compounds which have a fixed ratio (unless the metal can have different charges). For example, sodium and chlorine can only form one molecule and if you have 2 sodium atoms you can’t form a molecule with chlorine. Covalent compounds can form various different molecules like carbon and oxygen which can form CO, CO₂, and ${CO₂^{3-}}$.