Chemical Bonding and Intermolecular Forces

Ionic bond

An electrostatic attraction between oppositely charged ions produced by the transfer of electrons from a metal to a non-metal.

Covalent bond

A chemical bond formed when two non-metal atoms share one or more pairs of electrons.

Metallic bond

Bonding in metals in which positive metal ions are held together by a delocalised ‘sea’ of mobile valence electrons.

Hydrogen bond

A strong dipole–dipole interaction between H bonded to N, O or F and a lone pair on N, O or F in a neighbouring molecule.

Van der Waals forces

Weak intermolecular attractions that include London dispersion forces and dipole-induced dipole forces.

Dipole–dipole forces

Attractive forces between the positive end of one polar molecule and the negative end of another.

Atomic stability

The condition in which an atom attains a low-energy electron configuration, often an octet like that of a noble gas.

Octet rule

The tendency of main-group atoms to gain, lose or share electrons until they possess eight valence electrons.

Ionic compound

A solid composed of a lattice of cations and anions; it conducts electricity when molten or dissolved in water.

Polar covalent bond

A covalent bond in which electrons are shared unequally because of a difference in electronegativity.

Non-polar covalent bond

A covalent bond with equal (or nearly equal) sharing of electrons, resulting in no permanent dipole.

Crystal lattice

The regular, three-dimensional arrangement of ions in an ionic solid.

Metallic lattice

A structure consisting of metal cations arranged in a lattice surrounded by delocalised electrons.

Electronegativity

A measure of an atom’s ability to attract shared electrons in a chemical bond.

Coordinate covalent bond

A covalent bond in which both bonding electrons are supplied by the same atom.

Lewis structure

A diagram showing the arrangement of valence electrons around atoms in