KWUN TONG GOVERNMENT SECONDARY SCHOOL Half Yearly Examination, 2001-2002 Integrated Science Class : S.2 ( ) Max. Mark : 100 Name : ______Date : 15 -1-2002 Class No.: ______Time : 8:45-9:45am

ANSWER ALL THE QUESTIONS ON THE ANSWER SHEET PROVIDED

(A) Multiple-choice questions: Choose the best answer. (20%) 1 Which of the following does NOT give out any carbon dioxide? A. Smoking B. A green plant C. A burning candle D. An orange

2 Green plants in darkness: A. release carbon dioxide B. release oxygen C. produce starch D. use up all carbon dioxide

3 The products of respiration are: A. energy, water and carbon dioxide B. energy, food and carbon dioxide C. energy, food and oxygen D. energy and water

4 Which of the following descriptions about air is correct? A. It can change lime water milky. B. It contains many different gases. C. Breathed air contains no oxygen. D. It is white in colour.

5 Which of the following item(s) has/have higher content in breathed air than in unbreathed air? (1) water vapour (2) carbon dioxide (3) oxygen (4) nitrogen A. (1) and (2) only B. (2) and (3) only C. (1), (2), (4) only D. (1), (2), (3) and (4)

6 Which of the following is NOT an air pollutant? A. Sulphur dioxide B. Nitrogen dioxide C. Carbon monoxide D. Nitrogen

1 7 Which of the following things does NOT respire? A. grass B. rabbit C. stone D. tree

Directions: Questions (8) to (9) refer to the diagram below:

8 Which of the following factors can also cause the coloured liquid index to move towards the bell jar? (1) an increase in temperature (2) an increase in light intensity (3) an increase in air pressure A. (1) only B. (2) only C. (3) only D. (1) and (3) only

9 How can you set up a control for this experiment? A. a similar apparatus without the mouse. B. a similar apparatus without chemical X. C. a similar apparatus without the coloured liquid. D. a similar apparatus without the coloured liquid and chemical X.

Directions: Questions (10) to (11) refer to the diagram below.

10 What is the function of soda lime? A. To remove oxygen B. To remove carbon dioxide C. To act as an indicator of carbon dioxide D. To act as an indicator of oxygen

2 11 Which of the following is the correct set-up? A. (1) B. (2) C. (3) D. (4)

12 What is the reading shown by the following ammeter?

A. 2.3 A 2.6 A 3.2 A 3.4 A

13 We should not use water to put out an electric fire because A. water is not cold enough. B. water will damage the appliance. C. water will flow away. D. Water can conduct electricity.

14 The conditions needed for electricity to flow in a circuit are the circuit should have a switch and a cell. the circuit should have a cell and a bulb. the circuit should be closed and have a cell. the circuit should be closed and have a bulb.

15 Which of the following substances is a good conductor of electricity? A glass B copper C paper D rubber

3 16 If the bulbs in the following circuits are identical, in which case will the bulb be the brightest?

A B

C D

17 A substance which does not allow electricity to flow through it easily is ______. A insulator B conductor C sem-conductor D an element

18 Silver is good conductor of electricity because some of their______. A atoms are free to move B electrons are free to move C atoms contain excessive electrons D atoms are tiny

19 Which of the followings is NOT the effect of smoking? A heart disease B lung cancer C AIDS D yellow teeth and fingers

20 Resistance can be measured by A dry cell B wire C millimeter D multimeter

(B) True or False Statements (20%) Write 'T' for a true statement and 'F' for a false one. 1. Respiration is another term for breathing. 2. Through photosynthesis, green plants can change light energy into chemical energy.

4 3. We can use hydrogencarbonate indicator to absorb carbon dioxide. 4. Respiration only takes place when a green plant is not undergoing photosynthesis. 5. Green plants carry out photosynthesis in daytime and respiration at night. 6. Air pollution can cause lung diseases. 7. An electric current flows only if there is a switch in the circuit. 8. All metals can conduct electricity. 9. A switch is used to open or close a circuit. 10. Carbon can conduct electricity.

(C) Fill in the blanks with suitable words. (20%) 1. Only green plants can carry out photosynthesis since they have (a)______. 2. Air contains (b)______, (c)______, (d)______, water vapour and 1% of inert gases. 3. A dark blue colour can be observed when (e)______solution is added to a bowl of rice. 4. Food chains start with (f)______. 5. Current only flows from a cell if the circuit is completely (g)______. 6. A cell changes chemical energy into (h)______energy. 7. We use an (i)______to measure current. It must be connected in (j)______to the circuit under measurement. 8. We can control the current in a circuit by using a variable resistor or so called (k)______. 9. The unit of resistance is (l)______. 10. We use a (m)______to measure voltage. 11. There are many free (n)______inside a metal. 12. Water vapour can be tested with (o) ______paper. 13. A (p) ______experiment helps us to compare results obtained in the experiment. 14. When you smoke, (q) ______, (r) ______and (s) ______get into your body. 15. Air pollution index is high in Causeway Bay. It shows that (t)______is very serious in Hong Kong.

(D) Short questions: Answer the following questions. (40%) 1. According to the food chain below, answer the questions.

(a) State the producer(s). (2%) (b) State the consumer(s). (2%) (c) If the number of sheeps is decreasing, what happens? Why? (4%)

5 (Total: 8 marks) 2. The diagram below shows five test tubes containing hydrogencarbonate indicator solution which is originally red in colour. They are put under sunlight for five hours.

(a) State the results of the experiment. (5%) Colour of the Carbon dioxide content Boiling tube hydrogencarbonate (increase/no change/ decrease) indicator solution (1) (2) (3) (4) (5) (b) If the leaves in (1) and (3) are taken for an iodine test, what will be the colour changes? (i) For the leaf in (1) (1%) (ii) For the leaf in (3) (1%) (c) What is the function of boiling tube (5)? (1%) (d) State one precaution of this experiment. (2%) (Total: 10 marks)

3. The diagram below shows an experiment to burn a piece of bread.

6 dry

(a) State the colour changes of the following. (2%) Colour change Hydrogencarbonate indicator Dry cobalt chloride paper

(b) In another experiment, a piece of glowing bread is put into a jar of oxygen.

(i) What will happen to the bread? (1%) (ii) Complete the equation below to show the energy change of this process. (3%) ______energy →______energy + ______

(Total: 6 marks)

4. Explain briefly why the resistance of our bodies would decrease if we were lying.

(Total: 4 marks)

5 a) In an open circuit, is there any current flow? Why? (4%) b) What is the energy change in an electric circuit? (4%) ______energy stored in the cell → ______energy that electrons obtained from the cell → ______and ______energy of the bulb

(Total: 8 marks)

7 8 6. Study the figure and answer the following questions.

a) What can we conclude from the graph? (2%) b) What were the chances of dying from lung cancer for the women who smoked 15-24 cigarettes per day? (1%) c) Does this graph show that lung cancer is mainly caused by cigarette smoking? (1%)

(Total: 4 marks) END OF PAPER

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