Regents review chemistry

Ionic Bond

A bond formed between metals and nonmetals where electrons are transferred, characterized by high melting and boiling points, and the ability to conduct electricity when dissolved.

Covalent Bond

A bond formed between nonmetals where electrons are shared; includes polar bonds (unequal sharing) and nonpolar bonds (equal sharing).

Metallic Bond

A bond characterized by a 'sea of mobile electrons' shared among metal atoms, allowing them to conduct electricity in both solid and liquid phases.

Electronegativity

A measure that determines the type of bond formed: if the difference is ≥ 1.7 it indicates an ionic bond, if < 1.7 it indicates a covalent bond.

Molecular Polarity

A condition where a molecule is polar if it has polar bonds and is asymmetrical in shape; nonpolar molecules are symmetrical.

Hydrogen Bonding

The strongest type of intermolecular force occurring between hydrogen and electronegative atoms such as nitrogen, oxygen, or fluorine.

Dipole-Dipole

An intermolecular force that occurs between polar molecules with medium strength.

London Dispersion Forces (LDF)

The weakest intermolecular force present in all molecules but is the only force in nonpolar molecules, increasing with molecular size.

Solubility Principle

The principle that 'like dissolves like', meaning polar solvents dissolve polar substances and nonpolar solvents dissolve nonpolar substances.

Conductivity of Ionic Compounds

Ionic compounds conduct electricity only when they are in aqueous solution or molten, but not in solid form.

Network Solids

Strong covalent structures characterized by very high melting points and poor electrical conductivity, examples include diamond and SiO₂.