Materials

1. The process of grouping and sorting out is called classification.
2. Grouping of object in a proper way always help us to do our work efficiently.
3. Classification can be based on similarities and differences.
4. Materials which are non-living things are mainly two types.
   - Naturally occurring.        - Man-made
5. Materials can be classified as metals, glass, ceramics, plastics and fiber.
   Metals: An element which is shiny, a good conductor of heat and electricity, ductile, malleable, has a high melting point (eg. silver, gold)
   Glass: Sand (silica), soda (sodium carbonate) and lime (calcium carbonate) are mixed and melted. Glass is fragile and transparent.
   Ceramics: Greek word, 'Keramos' - which means potter's clay - All ceramics are made from various clay. Ceramics are compounds of silicon, carbon, oxygen and nitrogen combined with other elements like sodium, potassium, calcium and boron.
   Plastics: Plastics do not occur naturally but are man-made. 'Plastikos' - a greek word meaning 'to mould'. Common types of plastics are polythene, polystyrene, PVC and nylon. Plastics have many uses.
   Fiber: Fibers can be both man made like polyester, nylon or natural like cotton or wool.