1. Wood comes from trees Modified wood is treated wood or a material made from wood mixed with other substances. (i.e. Plywood, particleboard, fibreboard)

2. Degradation/Protection of wood and modified wood Lots of water = bad for wood Treated wood = protected wood 2 ways to treat wood - Dipping it in an alkaline solution containing copper. - Heating it to a high temperature.

3. Ceramics A ceramic is a solid material obtained by heating inorganic matter containing various compounds, usually oxides. (silicon dioxide) Ceramics : -Good insulators -High degree of hardness -Low thermal conductivity -Resistance to corrosion -Fragile -Some acids/bases degrade ceramics

4. Metals and Alloys Metal = from mineral ore - Good conductors of electricity and heat An alloy = mixture of metal + one or more substances (metal or non metal)

5. Degradation/Protection of metals & alloys Degradation = from corrosion (oxidation) Protection = Coating - Metallic coatings (zinc, gold, silver) - Non metallic coatings (paint, grease)

6. Heat Treatment  To enhance metal/alloy properties  steel (alloy made from iron + carbon)  steel heat treatment - To create harder steels using quench hardening and tempering. (3 stages) 1) heating (high) 2) cooling 3)heating (low)

7. Plastics Made of polymers (derived from fossil fuels) 2 types : - Thermoplastics (because soft when heated) -Thermosetting (remains hard even when heated)

8. Degradation/Protection of plastics - water, acids, oxidation, UV rays degrade plastics To protect = waterproof coating, add antioxidants, add pigments that absorb UV rays

9. Composites Formed by combining materials from different categories to obtain a material with enhanced properties Plastic + fibreglass (matrix) + reinforcement