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General Chemistry

Covalent Compounds

Definition and meaning of Covalent Compounds in chemistry.

Covalent compounds are chemical substances formed when two or more nonmetal atoms share pairs of electrons rather than transferring them, creating discrete molecules held together by covalent bonds.

In more detail

Sharing electrons lets each atom attain a stable outer-shell configuration (often satisfying the octet rule) without either atom fully gaining or losing electrons. Because covalent compounds exist as separate molecules rather than an extended ionic lattice, they typically have lower melting and boiling points than ionic compounds and do not conduct electricity as solids or in the pure liquid state. The bonds can be nonpolar (equal sharing, as in O2) or polar (unequal sharing due to differing electronegativities, as in HCl), which determines the compound's overall polarity and many of its physical properties.

Key facts

FieldGeneral Chemistry
Example formulaH2O
Typical elements involvedTwo or more nonmetals
Common propertiesLow melting/boiling point, poor electrical conductivity as pure substance
Example

Water (H2O) forms when one oxygen atom shares one electron pair with each of two hydrogen atoms, producing a bent, polar molecule.

Frequently asked questions

How do covalent compounds differ from ionic compounds?

Covalent compounds form when nonmetal atoms share electrons to make discrete molecules, while ionic compounds form when electrons transfer from a metal to a nonmetal, producing oppositely charged ions held in a crystal lattice.

Can covalent compounds conduct electricity?

Pure covalent compounds generally do not conduct electricity because they lack free ions or mobile electrons, though some, like HCl, become conductive when dissolved in water and ionize.

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