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In chemistry, compounds form when molecules combine through chemical reactions, creating either ionic or covalent (molecular) structures. These two classes differ fundamentally in bond type and physical properties.
Molecular compounds are held together by covalent bonds, where atoms share electron pairs. This shared‑electron attraction creates a stable structure that keeps the molecules bound. By contrast, ionic compounds arise when one atom donates electrons to another, resulting in oppositely charged ions that attract each other.
Because electrons remain localized within covalent bonds, molecular compounds typically exhibit poor conductivity of both electricity and heat. Even when molten or dissolved, their conductivity remains low. Ionic compounds, however, become conductive when melted or dissolved, as free ions carry charge.
Understanding these characteristics helps chemists predict compound behavior in reactions and real‑world applications.
