2. Ho Ka Ki (25) Lee Ka Wing (28) Lo Mung Ping (31) Ngan Wan Ting (35) Yeung Po Yee (40)

3. Introduction—Metals —Plastics Metals : Aluminium Plastics : Polystyrene Comparison—Properties —Uses

4. From metal ores by chemical or electrolytic reduction Are lustrous, ductile, malleable, and good conductors of heat and electricity. Can be processed into alloys. widely used in past & modern world.

5.  Made by raw materials from crude oil  Major elements carbon & hydrogen Widely used in recent decades unique properties  When being disposed of improperly environmental problems polyethene polystyrene

6. Symbol: Al Silvery,ductile,lightweight metals. Found primarily in bauxite ore The most abundant metal in earth crust Used to manufacture a large variety of products Very important to world economy

7. It is colorless, hard with limited flexibility and a polymer made from styrene. Production Heat the mixture of styrene and kerosene pour it into methanol after cooling waxy, solid of polystyrene formed Danger Benzene, a material used to produce polystyrene, is human carcinogens.

8. MaterialsAluminium (Al)Polystyrene (PS) Conduct heat and electricity YesNo BurnableYesNo StrengthlowerHigher No Densitylow ShinyYes RecyclableYes(e.g.Aluminium cans)Yes(e.g. Plastic cups) Resistant to corrosionYes Transparent Possible ___:Differences ___:Similarities

9. MaterialsAluminium (Al)Polystyrene (PS) Household uses-Cooking appliances -Window frames -Lamps -Switches -Plastic cups Other uses-Aeroplanes -Cable -CDs -Medicine bottles -Expanded foams -Toys Price$24000/ton$12000/ton