.

• Red: Reduction

  Ox: oxidation
• Oxidation

  Is

  Loss of electrons

  Reduction

  Is

  Gain of electrons
• Oxidation state of Uncombined elements is 0
• Oxidation state of Group 1 metals is +1
• Oxidation state of Group 2 metals is +2
• Oxidation state of Group 3 ions are +3
• Oxidation state of group 7 is -1, except when it bonded with fluorine, the oxidation state is +1.
• Oxidation state of Fluorine is always -1
• Oxidation state of hydrogen is +1 unless it forms a metal hydride, it is -1. (e.g. NaH)
• Oxidation state of Oxygen is -2 except in hydrogen peroxide, where it is -1.
• Half equations show only oxidation or reduction taking place.
• Redox equations show both Oxidation and Reduction taking place together.
• To balance a Oxidation half equation (Loss of electrons), use electron (e-).
• To balance a Reduction half equation (gain of electrons), use water (H2O+), then H+ ions and/ or e- to balance.
• Oxidising agent oxidises something and gets reduced.
• Reducing agent reduces something and gets oxidised.
• Combustion is redox.
• Redox reactions have pure elements.
• Acid-base neutralisation reaction is not redox.
• Double replacement reaction is not redox, when single replacement reactions are always redox.