Transcript Comparing Metals and Plastics

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Ho Ka Ki
Lee Ka Wing
Lo Mung Ping
Ngan Wan Ting
Yeung Po Yee
(25)
(28)
(31)
(35)
(40)
• Introduction—Metals
—Plastics
• Metals : Aluminium
• Plastics : Polystyrene
• Comparison—Properties
—Uses
•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.
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
polystyrene
polyethene
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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
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.
Materials
Aluminium (Al)
Polystyrene (PS)
Conduct heat
and electricity
Yes
No
Burnable
Yes
No
Strength
lower
Higher
Transparent
Density
No
Possible
low
low
Shiny
Yes
Yes
Recyclable
Yes(e.g.Aluminium cans)
Yes(e.g. Plastic cups)
Resistant to corrosion
Yes
Yes
___:Differences
___:Similarities
Materials
Aluminium (Al)
Polystyrene (PS)
Household uses
-Cooking appliances
-Window frames
Other uses
-Aeroplanes
-Cable
-CDs
$24000/ton
-Lamps
-Switches
-Plastic cups
-Medicine bottles
-Expanded foams
-Toys
$12000/ton
Price