Deffinitions - Chemistry

The first ionisation energy of an element is the energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to produce 1 mole of gaseous ions, each with a +1 charge.

Succesive ionisation energies are the sequence of 1st, 2nd, 3rd, etc. ionisation energies required to remove the 1st, 2nd, 3rd, etc. electrons from each atom in 1 mole of gaseous atoms of an element.

This is the ability of an atom to attract the bonding pair of electrons.

Empirical Formula - the simplest whole number ration in a molecule.

Molecular Formula - the actual number of atoms in a molecule.

The oxidation number is the number of electrons that an atom uses to bond with atoms of anouther element.

Atomic Number - the number of protons in the nucleus of an atom (also equal to the number of electrons)

Mass Number - the number of protons plus neutrons in the nucleus of an atom

Ionic - Metal + non-Metal

Cobalent - Non-Metals only

Metallic - Metals only

An orbital is simply a region in space where we are likely to find electrons.

Order of Filling -

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 5d, etc.

When 3d gains electrons it lowers in energy and becomes part of the 3rd shell.