UNIT VII- MATERIALS
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Specific Objectives
Students should be able to: |
Explanatory notes
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Suggested Practical Activities
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1
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Relate the uses of metals and non-metals in the home, to their properties |
Metals, plastics and wood; properties such as electrical conductivity, thermal conductivity, melting point, density, tensile strength.
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2
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Discuss the advantages and disadvantages of using plastics;
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Negative effects on the environment of using plastics. |
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3
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Describe the reactions of metals; |
(Al) Aluminum; (Cu) Copper; (Fe) Iron; (Sn) Tin; (Ag) Silver; (Zn) Zinc; with oxygen, acid, alkali, water and steam.
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Observe which metals react and which do not; simple word equations to show their reaction.
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4
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Discuss the advantages and disadvantages of using cooking or canning utensils made of aluminum; |
Copper, iron, tin, silver, zinc; consideration of toxicity and corrosion. |
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5 |
Discuss methods of cleaning household appliances; |
Household appliances made of aluminum, copper, iron, tin, silver, and zinc. |
Demonstrate simple methods of cleaning household appliances make of aluminum, copper, iron, tin, silver, zinc. |
6 |
Discuss the effectiveness of various types of abrasives; |
Corrosion and toxicity. |
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7 |
Discuss the benefits of using alloys to make household items; |
Alloy and examples of alloys commonly found in the home and workplace. |
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8 |
Discuss the conditions which cause rusting; |
Steel, brass and soft solder. Tarnishing as a chemical process (oxidative). |
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9 |
Identify the factors which affect the rate of rusting; |
Problems of rusting metal fixtures in houses located near the sea or an industrial plant. |
Controlled experiments to show that air and water are necessary for rusting. |
10 |
Discuss methods to reduce or prevent rusting of iron or steel; |
Painting, covering with oil, electroplating; galvanizing; the scientific principles involved, commercial as well as household. |
Demonstrate ways of removing rust marks on clothing. |
Go to Section B: UNIT VIII- LIGHTING
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