Compound

A substance that is made up of two or more different elements chemically combined

Octet rule

When bonding occurs, atoms tend to reach an electron arrangement with eight electrons in the outermost energy level

Ionic bond

The force of attraction between oppositely charged ions in a compound

Crystal lattice

The 3D arrangement of ions

Chemical formula

A way of representing a compound using symbols for the atoms present and numbers to show how many atoms of each element is present

Transition element

One that forms at least one ion wit a partially d sublevel

Covalent bond

Consists of one or more shared pairs of electrons, each of the bonded atoms contribution towards the shared pair

Valency

The no. of atoms of H with which the atom of the element combines

Electronegativity

The relative attraction that an atom in a molecule has for the shared pairs of electrons in a covalent bond

Polar covalent bond

A bond in which there is unequal sharing of electrons which causes one end of the bond to have a slightly positive charge and one other end slightly negative charge

intramolecular bonds

Bonds within molecules (ionic and covalent)

intermolecular bonds

forces of attraction that exists between molecules themselves

Van Der Waals forces

Weak attractive forces between molecules resulting in the formation of temporary dipoles

Dipole-dipole forces

Forces of attraction between the negative pole of one polar molecule and the positive pole of another polar molecule

Hydrogen bonding

Particular types of dipole-dipole attractions between molecules in which hydrogen atoms are bonded to N, O or F