1. Metal

2. 1.Which of the following metals are firstly used by human? (i) gold (ii) silver (iii) copper (iv) bronze (v) iron Only (i) and (ii) Only (i) 、 (ii) and (iii) Only (i) 、 (ii) 、 (iii) and (iv) (i) 、 (ii) 、 (iii) 、 (iv) and (v)

3. 2. Which of the followings are properties of gold? (i) It rarely combine with other substances. (ii) It has a very unique colour (iii) It is relatively hard (iv) It is relatively soft Only (i) and (ii) Only (i), (ii), (iii) Only (i), (ii) and (iv) (i), (ii), (iii), (iv)

4. 3. Gold are mainly used to make daily utensils. decorative items. coins. electric wire.

5. 4. Throughout history, silver is always be used to make make daily utensils. electric wire. coins. musical instruments.

6. 5. Why copper is widely used in daily life? It is because copper is cheap. It is because copper is available in great quantity. It is because copper is a good conductor of electricity. It is because copper is a good conductor of heat.

7. 6.Many daily utensils are made of bronze instead of copper. It is because bronze is cheaper than copper. bronze is harder than copper. the colour of bronze is more beautiful. using copper to produce daily utensils is more expensive than bronze.

8. 7. The history of using metals is closely related to : (I) only (II) only (I) & (II) only (I) & (III) only (I)The properties of the metal (II)The abundance of the metal on earth (III)The level of difficulty in extracting the metal

9. 8. Most metals have combined with ______ and exist in the form of metal ores on earth. (I) only (I) & (II) only (I), (II)& (III) only (I), (II), (III) & (IV) (I)carbon (II)oxygen (III)sulphur (IV)hydrogen

10. 9. Metals ores mainly consists of ______ of metals (I) and (II) only (I) & (II) & (III) only (I), (II), (III) & (IV) only (I), (II), (III), (IV)& (V) (I)oxides (II)sulphides (III)halides (IV)carbonates (V)sulphates

11. 10. From the view of chemistry, the principle of extracting metal from ore is by using the method of carbon reduction and extract the metal from the ore. to melt the metal ore. to decompose the metal ore to separate the metal from other substances in the metal ore

12. 11. Aluminium can be used to make aeroplanes, space shuttles and the outer layer of trains, because aluminium is a good conductor of electricity. aluminium is available in great quantity. aluminium is cheap. aluminium has low density, but it is very hard.

13. 12. Which of the following is NOT the properties of copper ? copper ? Good conductor of electricity. High ductility and malleability. Corroded by air easily. Good conductor of heat.

14. 13. Which of the following property of gold and silver make them can act as good reflectors? Great mechanical strength. They combine with oxygen in air and form a layer of oxide on the surface. Shininess. High electrical conductivity.

15. 14. Which of the following correctly states the application of lead and magnesium? Lead – to insulate against radiation Magnesium – making fireworks Lead – tinted on the surface of the satellite Magnesium – to insulate against radiation. Lead – tinted on the back surface of glass Magnesium – making fireworks Lead – to insulate against radiation Magnesium – tinted on the surface of the satellite.

16. 15. Which of the following is the only metal in liquid form? Mercury Titanium Chromium Manganese

17. 16. Bronze is a metal alloy made from copper and iron. copper and aluminium. copper and tin. copper and zinc.

18. 17. Brass is a metal alloy made from copper and iron. copper and aluminium. copper and tin. copper and zinc.

19. 18. Solder is a metal alloy made from lead and tin. lead and copper. iron and tin. iron and copper.

20. 19. Carbon steel is a metal alloy made from carbon and _________. and _________. copper iron zinc steel

21. 21. The % of carbon in carbon steel is about 1% 2% 10% 20%

22. 22. Stainless steel is a metal alloy made from iron and tin. iron and chromium. iron and zinc. iron and steel.

23. 23. The % of chromium in stainless steel is not less than 2% 5% 12% 20%

24. 23. Shape-memory alloy can memorize shapes. It is because shape-memory alloy has only one phase in their solid state. shape-memory alloy has two different phases in their solid state. shape-memory alloy has three different phases in their solid state. particles of shape-memory alloy have different arrangement in solid and liquid state.