3. This Photo by Unknown Author is licensed under CC BY-SA
4. ELECTRON TRANSFER
• Iron + Oxygen → iron oxide
• corrosion of metals occurs through electron transfer.
• When reactions occur an exchange of elections takes place.
• The exchange of electrons leads to the change in charges (grade 10,
reactions in aqueous solution)
• When an atom gains electrons it becomes more negative, when it
loses electrons it becomes more positive.
5. OXIDATION AND REDUCTION
• involving two processes, oxidation and reduction.
• Electron transfer occurs when one atom, ion or element loses an
electron and one gains that electron.
• The loss of electron is known as Oxidation
• The gain of electrons is known as Reduction.
6. OIL RIG
• Oxidation is loss
• Reduction is gain
MOVEMENT OF ELECTRONS FROM ONE ATOM TO ANOTHER
•
• A- LOSING ELETRON (OXIDATION)
• B – GAINING ELECTRON (REDUCTION)
A ELECTRON B
8. EXAMPLES
2Mg + O2 → 2MgO
Magnesium undergoes oxidation
Oxygen undergoes reduction
2. 4Fe + 3O2 → 2FeO3
Fe has lost electrons, therefore it undergoes oxidation
Oxygen gains electrons, therefore it undergoes reduction
9. OXIDATION AND REDUCTION
When an atom undergoes oxidation it is oxidised.
When it undergoes reduction it is reduced.
An oxidised atom is also called a reducing agent.
A reduced atom is also called an oxidising agent.
