Ion

Lone pair

Bond pair

Octet rule

Valency

Electronegativity

An atom or group of atoms that has lost or gained electrons to become either positively or negatively charged

Pair of electrons in the outer shell of an atom that are not involved in bonding

Shared pair of electrons that form a covalent bond

When atoms react, they tend to reach an electron arrangement with eight electrons in their outermost energy level

The number of electrons which an atom of an element must gain, lose or share in order to achieve a noble gas structure````

Measure of the attraction of an atom of an element for the shared pair of electrons in a covalent bond