Final answer:
A compound most likely to contain a covalent bond is one composed of only nonmetals, as these atoms share electrons to form stable molecules.
Step-by-step explanation:
The type of compound that is most likely to contain a covalent bond is one that is composed of only nonmetals. Covalent compounds are characterized by the sharing of electrons between atoms, which typically occurs between nonmetallic elements. These electrons are shared to fill their outer valence shell and achieve a more stable electronic configuration. Within the periodic table, nonmetals are found to the right side and tend to have higher electronegativities. This contrasts with ionic compounds, which generally form between metals and nonmetals, where there is a transfer of electrons to form charged ions.