Science SATs 2005 Paper 2 Tier 5 to 7

1. Science SATs 2005 Paper 2 Tier 5 to 7

2. To Pupils:We hope this presentation will help you understand how your paper was marked and how you might improve your performance. The answers shown are some of the most commonly expected responses.To save space many answers have not been written as fully as they should be.Not all options and versions have been included.To Staff:It is vital for you to have access to the official KS3 mark scheme.

3. 1. The drawing below shows a garden water feature. It is solar-powered. The solar cell absorbs energy from the Sun. The solar cell is connected to a motor in the bowl. The motor drives a pump. Water is pumped up to the jug and it flows back down to the bowl.

4. chemical electrical gravitational potential kinetic light sound thermal • The useful energy change in the solar cell is from light to …….……….. energy. • (ii) The useful energy change in the motor is from electrical energy to ……………… energy. • (iii) As the water flows from the jug to the bowl ……………………. energy is changed into ……………….. energy. (a) Use the information above to help you to complete the following sentences. Choose words from the list. 1 electrical 1 kinetic Gravitational potential 2 Kinetic or Sound/ thermal

5. 1 The energy will can be replaced/ renewable energy/free to run • Give one advantage and one disadvantage of using a solar cell to power the water feature. Advantage Disadvantage 1 pump stops when no sun/light/ or dark/night

6. a) Complete the table below by writing on or off for each bulb. One has been done for you 2. Lorna built the circuit drawn below. All the bulbs are identical. OFF OFF OFF OFF 1 ON ON ON ON 1 ON ON OFF OFF 1

7. b) Lorna then built a different circuit as shown below. 1 How could Lorna get both bulbs to light at the same time in this circuit? Close S4 and S5 leave S3 open

8. 1 O O O O O Same size particles and spread out randomly 3. (a) (i) Air contains nitrogen. In the box below draw five circles, 0, to show the arrangement of particles in nitrogen gas. (ii) Zeena carries a personal emergency alarm. It uses nitrogen gas to produce a very loud sound. The nitrogen gas in the container is under much higher pressure than the nitrogen gas in the air How does the arrangement of nitrogen particles change when the gas is under higher pressure? 1 Closer together

9. greater than less than the same as b) Use words from the boxes below to complete the sentence. The rate at which the nitrogen particles hit the inside of the container is ………………………………….. the rate at which nitrogen particles hit the outside of the container greater than 1

10. (i) The loudness of the sound produced by the alarm decreases between X and Y. How can you tell this from the graph? c) Zeena pushes the lid down and nitrogen gas escapes through the diaphragm. The diaphragm vibrates and produces a sound. The pattern on the oscilloscope screen below represents the soundwave produced by the alarm. 1 amplitude gets smaller / wave height gets shorter (ii) The pitch of the sound produced by the alarm stays the same between X and Y. How can you tell this from the graph? 1 peaks or troughs spaced equally / frequency is constant /unchanged

11. (a) In the table below, tick one box for each liquid to show whether it is acidic, neutral or alkaline. One has been done for you. 4. Molly used a pH sensor to test different liquids. She dipped the probe of the sensor into each liquid and recorded the pH value in a table. √ probe √ √ √ 2

12. 1 clean the probe / prevent contamination / accurate readings not mixed up the liquids/ distilled water is neutral / pH7 (b) Between each test Molly dipped the probe into distilled water (i) Why did she do this? (ii) Which other liquid in the table could Molly use between tests to have the same effect as distilled water? 1 alcohol

13. (i) Molly thought that magnesium would reactmore vigorously with hydrochloric acid than with vinegar. What information in the table made Molly think this? c) Molly put a piece of magnesium into a test-tube containing 20 cm3 of vinegar. She put another piece of magnesium into a test-tube containing 20 cm3 of dilute hydrochloric acid. 1 Hydrochloric acid has lower pH / more acidic. (ii) How would Molly be able to tell if a more vigorous reaction took place with hydrochloric acid than with vinegar? (d) (i) Complete the word equation for the reaction between magnesium and hydrochloric acid. magnesium + hydrochloric acid  ………………. + …………………. (ii) After some time this reaction stopped. Why did the reaction stop? 1 More fizz/bubbles 2 magnesium chloride + hydrogen 1 all acid used up / magnesium used up

14. Group 1 recorded their results in the table below. results of group I 5. Two groups of pupils investigated the factors affecting the time taken for an indigestion tablet to dissolve in 100 cm3 of water • What factor did group 1 change as they carried out their investigation? • (b) Before the investigation, group 1 made a prediction. They found this prediction was supported by the results in the table. What prediction did group 1 make? 1 Size of tablet crushed/pieces /Surface area of the tablet 1 Crushed tablets will dissolve faster than whole tablets. A whole tablet will take longer to dissolve. The bigger the surface area the faster it dissolves

15. Group 2 investigated how the temperature of the water affects the time taken for a whole tablet to dissolve. Here are their results. Results of group 2 • What factor did group 2 change as they carried out their investigation? • What pattern do the results recorded by group 2 show? • Look at the results presented by group 1 and group 2. Both groups used the same type of tablet. Estimate the temperature of water used by group 1 • ………………… (0C) 1 Water temperature 1 The higher the temperature the quicker the tablet dissolves. OR The lower the temperature the longer the time for the tablet to dissolve 40 (38-44) 1

16. cervix ovary 6. (a) When fertilisation takes place, the nucleus of a sperm joins with the nucleus of an ovum (egg) In which part of the reproductive system does fertilisation normally take place in humans? Tick the correct box. √ uterus 1 oviduct

17. (b) The table below gives information about fertilisation in three animals. Frogs release their eggs and sperm into water. The eggs are fertilised in the water. Why is it an advantage for frogs to release large numbers of eggs and sperm? 1 large numbers increase chance of an egg being fertilised / Some eggs or sperm might be eaten /some eggs might not be fertilised /some washed away

18. c) The diagram shows a section through a fertilised egg of a bird. (i) The shell of a bird’s egg is porous. This means it has microscopic holes in it. Why does it need to be porous? (ii) Give one other function of the egg shell. 1 let oxygen into the egg /allow gas exchange for respiration 1 Protection /stops egg drying out (d) A bird’s egg contains yolk which is a food store for the developing chick. A human egg does not contain yolk. Why does a human egg not need to contain a food store for the embryo? 1 Foods from the mother’s blood to the embryo /through the placenta

19. Give the name and function of part P • Name • Function 1 nucleus 7. (a) The diagram below shows a group of cells from the lining of the mouth. 1 Controls cell activities (ii) Which word describes this group of cells? Tick the correct box Compound Organism Organ Tissue √ 1

20. (i) Muscle cells can contract. Give one reason why muscles are needed in the intestine. 1 b) The diagram below shows muscle cells from the wall of the human intestine. push food /contents of gut along/help break up large food pieces (ii) Other cells in the human intestine produce enzymes. What effect do enzymes in the intestine have on nutrients such as protein? 1 Enzymes speed up digestion (iii) Which of the following is required in the diet to keep food moving through the intestine? Tick the correct box. √ Fat Protein Fibre Starch 1

21. 8. Suzi investigated how temperature affects the number of bubbles produced by waterweed in one minute. She set up the experiment as shown below. When the temperature of the water was 10°C the waterweed did not produce bubbles. (a) Suzi increased the temperature of the water in the water-bath to 20°C. The waterweed started to produce bubbles. She waited two minutes before starting to count the bubbles. Explain why she waited for two minutes before she started to count the bubbles. 1 make sure the water in the boiling tube had reached the required temperature/ make sure adjusted to the new temperature

22. Number of bubbles produced (per min) • Draw a smooth curve on the graph b) Suzi counted the number of bubbles produced at six different temperatures. Her results are shown on the graph below. A smooth curve through all 6 points (A to F) 1 (ii) Use your curve to find the temperature of the water which produced the most bubbles per minute ……….……. 0C 1 32 to 38 c) Suzi predicted that the higher the temperature the more bubbles would be produced. Which points on the graph support Suzi’s prediction? 1 A, B, C / between 10oC and 300C d) Suzi’s data does not show clearly the exact temperature at which most bubbles were produced. How could she improve the data she collects to find this temperature? 1 smaller intervals between 300C and 400C

23. Questions only on the 5 to 7 paper 2

24. 9 A reed switch is made of two iron strips inside a glass tube. The iron strips close together when a magnet is brought near. They spring apart again when the magnet is removed. (a) Hilary set up the circuit shown below. She tried to close the reed switch using an electromagnet. • She closed switch E but the electromagnet was not strong enough to close the reed switch. • Give two ways Hilary could increase the strength of the electromagnet. • 1 • 2 2 add more coils or turns increase the current

25. a) (ii) Hilary increased the strength of the electromagnet. The reed switch closed. The iron strips were magnetised as shown below. She reversed the current in the coil of the electromagnet. On the diagram below, label the poles of the iron strips when the current was reversed. 1 N S N S (b) (i) Iron and steel are both magnetic materials. Explain why the strips must be made of iron and not steel. 1 Steel stays magnetised / Iron loses its magnetism The switch would stay closed / would not spring open (ii) She replaced the reed switch with a piece of copper wire. The current through the bulb increased. Explain why more current flowed through the bulb when the reed switch was replaced with copper wire. 1 Copper is a better conductor than iron

26. 10. John used an electrical heater to heat a cup of water. He kept stirring the water When the temperature reached 20°C, he started his stopwatch and measured the temperature of the water every half minute. He switched off the heater after 4 minutes, but continued to record the temperature. His results are shown in the table. One measurement is missing and another appears to be wrong.

27. 4 Marks 1 Appropriate scale/size 2 Axes labelled with units 3 Points plotted neatly 4 Best fit smooth curve a) Use the results in the table to draw a graph on the grid. Label the axes. Plot the points and draw a smooth curve of best fit ………….. (………) ………….. (………) b) From your curve, estimate the temperature of the water after three minutes. …………… 0C 1

28. a) Use the results in the table to draw a graph on the grid. Label the axes. Plot the points and draw a smooth curve of best fit 60 ………….. (………) Temperature oC 40 20 1 2 3 4 5 6 ………….. (………) Time (mins) b) From your curve, estimate the temperature of the water after three minutes. …………… 0C 53 +/-

29. most reactive potassium sodium magnesium aluminium iron leadleast reactive copper 11. Part of the reactivity series of metals is shown below. • Dan added a piece of magnesium to a solution of copper sulphate. • A displacement reaction took place. The word equation for the reaction is shown below. magnesium + copper sulphate  magnesium sulphate + copper Why is this called a displacement reaction? 1 Magnesium displaces copper from the copper sulphate Copper is replaced by magnesium

30. 2 b) Look at each pair of chemicals in the table below. Use the reactivity series to predict whether a displacement reaction would take place. Write yes or no in the second column and give the reason for your decision. because NO Iron is below sodium YES Magnesium is above lead • Dan wanted to find out where zinc should be placed in the reactivity series. • (i) What tests should Dan do to find out the correct position of zinc in the reactivity series? 1 Add zinc to a solution of a salt of each of the other metals. Add each of the other metals to a solution of a zinc salt (ii) How would Dan use his test results to decide where to put zinc in the reactivity series? 1 Place zinc between the metal which does react and the one which does not

31. 12. As apples become ripe they produce a gas called ethene. Ethene passes through the air from ripe apples to unripe apples. Ethene causes unripe apples to ripen more quickly. Three effects of ethene on apples are listed below. • The green substance, chlorophyll, breaks down. • Starch breaks down to form glucose. • Pectin, a substance which holds cells together, breaks down. Describe and explain the changes you would notice when apples become ripe as a result of any two of these effects. • changeexplanation • change explanation changes colour /less green because chlorophyll breaks down OR 1 sweeter because glucose is formed OR 1 softer because cells break apart without pectin 1 b) Give the name of the process by which gases such as ethene spread through the air in a room. diffusion

32. H H C C H H c) The diagram below represents a molecule of ethene. • Ethene is flammable and must be kept away from naked flames. Look at the diagram of the molecule of ethene. Give the name and chemical formula of the two compounds formed when ethene burns in oxygen. • Name ………………………………… • Formula ……………… • Name …………………………………. • Formula ……………… Carbon dioxide 1 CO2 Water 1 H2O

33. The table shows how hydrogencarbonate indicator solution changes colour when the concentration of carbon dioxide in it changes. Sunil set up the experiment shown below and put both test-tubes on a window-sill.

34. 1 Respiration 1 Use information in the table to help you answer the questions below. (a) The indicator in test tube A changed from orange to yellow. (i) What process, in the cells of the maggots, caused this colour change? (ii) Explain what happens in this process to cause the colour change. Carbon dioxide reacts with water to make an acid (carbonic acid) (b) The indicator in test-tube B changed from orange to purple. (i) What process, in the cells of the leaves, caused this colour change? (ii) Explain what happens in this process to cause the colour change. 1 Photosynthesis 1 Carbon dioxide is used up/ oxygen made turns the liquid alkaline

35. (c) Sunil then put two fresh leaves into test-tube C containing 30 cm3 of orange hydrogencarbonate indicator. He added some maggots on a piece of wire mesh as shown below. He put the test-tube on a window-sill. The indicator remained orange. Explain why. …………………………………………………………………………. 1 Carbon dioxide produced by maggots / respiration was used up in photosynthesis

36. Why can the results of this research not be used to draw any conclusions about heart disease among women across the world? • b) Give one reason why the data collected in this study is likely to be reliable 14 Read the magazine cutting about research into heart disease. 1 only investigated British women only 60-79 age group 1 used a large sample (4286)

37. (c) After reading the magazine cutting, pupils wrote the ideas below. Decide if each idea is supported by information in the cutting. Tick the correct box. Use the information in the cutting as evidence to justify your decision in the third column data refers only to older women 1 √ no evidence of the impact of treatment √ 1 data suggests 1/5 had signs of heart disease so 4/5 are unlikely to suffer √ 1

38. End of paper 2 Tier 5 to 7 2005