Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2009 May/June Paper 2 · Variant 1

This document consists of 25 printed pages and 3 blank pages. IB09 06_0654_02/4RP © UCLES 2009 [Turn over *5980707665* For Examiner's Use 1 2 3 4 5 6 7 8 9 10 11 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/02 Paper 2 (Core) May/June 2009 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 28. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 1 (a) Many people have survived accidents where they have been exposed to ionising radiation from radioactive materials. Such exposure can have serious effects on their health. The table and graph show how the dose (amount) of radiation received is linked to a type of cancer called leukaemia. The radiation dose is measured in units called grays. Table 1.1 radiation dose / grays incidences of leukaemia / cases per 10 000 people per year 1.0 1.0 2.5 2.3 5.0 10.0 10.1 15.0 15.2 incidences of leukaemia / cases per 10 000 people per year 16 14 12 10 8 6 4 2 0 0 2 4 6 8 radiation dose / grays 10 12 14 16 Fig. 1.1

3 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (i) The result for 5.0 grays has been missed out of the table. Use the graph to help you fill in the missing result in the table. [1] (ii) What is the relationship between the ionising radiation and the incidence of leukaemia? [1] (iii) Name one other health hazard, apart from leukaemia and other cancers, caused by ionising radiation. [1] (b) The three types of nuclear radiation from naturally occurring sources are alpha, beta and gamma. They can be identified by their different penetrating powers. Gamma radiation can pass through a thick layer of lead. Explain how you could identify alpha and beta radiation by their penetrating powers. alpha radiation beta radiation [2] (c) Radon-222 has a half-life of four days. (i) What is meant by the term half-life? [1] (ii) 1 milligram of radon-222 is allowed to decay. Calculate after how many days there would be 0.125 milligrams of radon-222 remaining. Show your working. [2]

4 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 2 Fig. 2.1 shows the water cycle. land river sea A B D C Fig. 2.1 (a) Choose the word from the list below that describes each of the stages A, B, C and D. condensation evaporation melting osmosis precipitation transpiration A B C D [4] (b) Describe two ways in which deforestation may affect the water cycle. [2]

5 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (c) Water is an essential part of the diet. Water is absorbed from the alimentary canal into the blood. It is transported around the body to every cell. (i) Name the part of the blood that transports water around the body. [1] (ii) Describe how water moves from the blood into a body cell. [3] (d) Water that is to be used for drinking is often treated with chlorine. Explain why this is done. [2]

6 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 3 Food colourings contain molecules which make food appear coloured. (a) Explain the meaning of the term molecule. [2] (b) Fig. 3.1 shows two pieces of cloth, A and B, stained with the same food colouring. A B Fig. 3.1 Cloth A was washed with soap in hard water. Cloth B was washed in the same way with the same amount of soap in soft water. Fig. 3.2 shows the pieces of cloth after washing. A B Fig. 3.2 Explain briefly, in terms of water hardness, why more of the food colouring was removed from cloth B than from cloth A. [3]

7 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (c) One compound which causes hardness in water is calcium hydrogencarbonate, Ca(HCO3)2. (i) State the total number of atoms which are shown combined in the formula of calcium hydrogencarbonate. [1] (ii) State the number of electrons in the outer energy level (shell) of a calcium atom. Explain your answer briefly. number of outer electrons explanation [2]

8 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 4 (a) A student investigated how a change in potential difference across a lamp affected the current flowing through it. She used wires to connect the components shown in Fig. 4.1 to make a circuit. V A Fig. 4.1 (i) Using the correct symbols from Fig. 4.1, draw a diagram to show the circuit she used. [3] (ii) Explain why the variable resistor is included in the circuit. [1]

9 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (iii) Her results are shown in Table 4.1. Table 4.1 potential difference across lamp / V current through lamp / A resistance of lamp filament / Ω 4 1.2 3.3 8 1.5 12 1.7 7.1 Complete the table by calculating the missing resistance and writing your answer in the empty box. State the formula that you use and show your working. formula working [2] (iv) The student concluded that the relationship between potential difference and current did not correspond to Ohm’s law. Explain why the relationship between potential difference and current for the lamp did not correspond to Ohm’s law. [2]

10 © UCLES 2009 0654/02/M/J/09 For Examiner's Use (b) Electricity can kill. Identify and explain the electrical hazard shown in Fig. 4.2. Fig. 4.2 [2]

11 0654/02/M/J/09 [Turn over BLANK PAGE Please turn over for Question 5.

12 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 5 Fig. 5.1 shows three vertebrates. A B C Fig. 5.1 (a) (i) Animal A is a bird. State two features, visible on Fig. 5.1, that are characteristic of birds. 1 2 [2] (ii) Name the classes to which animals B and C belong. B C [2] (iii) Animal C belongs to the genus Rana and the species temporaria. Write the binomial for animal C. [1] (iv) Animal C spends part of its time in water. Describe one way, visible in Fig. 5.1, in which animal C is adapted for life in water. [2]

13 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (b) Fig. 5.2 shows how the temperatures of animal A and animal C change when the temperature of their environment changes. temperature of environment temperature of animal A C Fig. 5.2 (i) Explain how Fig. 5.2 shows that animal A regulates its temperature but animal C does not. [1] (ii) Name one group of vertebrates, other than birds, that regulates body temperature. [1] (iii) Explain why it is useful to regulate body temperature. [2] (iv) Animals that regulate their body temperature need to eat much more food than animals that do not. Suggest an explanation for this. [2]

14 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 6 (a) Many metals react with dilute acids. Complete the word equation for the reaction of magnesium with dilute sulfuric acid. dilute sulfuric acid + magnesium + [2] (b) A student used the apparatus shown in Fig. 6.1 to investigate the rate of reaction between sulfuric acid and magnesium. To start the reaction, she tilted the flask to mix the reactants. sulfuric acid flask magnesium measuring cylinder full of water Fig. 6.1 She timed how long it took for 30.0 cm3 of gas to collect in the measuring cylinder. Some of her results are shown in Table 6.1. Table 6.1 experiment number time to collect 30 cm3 gas / seconds 1 73 2 41 3 119 (i) Explain in which experiment, 1, 2 or 3, the rate of reaction was highest. [1]

15 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (ii) Suggest two changes to the reaction conditions in experiment 1 that would cause the rate of reaction to decrease. 1 2 [2] (iii) During experiment 1, the student noticed that the flask became warm. Explain this observation. [2]

16 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 7 A diver is working under water, wearing a diving suit and helmet. (a) The diving helmet has a plastic window of area 100 cm2. The air pressure inside the helmet is the same as the water pressure outside. (i) At a depth of 40 m, the diver breathes air at a pressure of 50 N / cm2. Calculate the force exerted by the air on the helmet window at this depth. Use the formula pressure = force / area Show your working. N [2] (ii) At the surface of the sea, the pressure of the atmosphere is 10 N / cm2. Suggest a value for the pressure at a depth of 10 m. Explain your answer. N / cm2 [2]

17 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (b) The diver sees a squid. A squid moves by forcing out a jet of water. This moving water has momentum. The mass of water forced out is 1.2 kg and has a velocity of 10 m / s. Calculate the momentum of the moving water. State the formula that you use and show your working. formula working kg m / s [2] (c) Water waves on the surface of the sea are transverse waves. (i) Give one other example of a transverse wave. [1] (ii) How does a transverse wave differ from a longitudinal wave? [1]

18 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 8 A student carried out an investigation into the response of plant shoots to light. He grew four maize seedlings and treated them as follows. • He did nothing to seedlings A and B. • He cut the tip off seedling C. • He covered the tips of seedling D with black paper. He placed seedling A where it received light from all directions. He placed seedlings B, C and D in a container where they received light from one side only. Fig. 8.1 shows the appearance of the four seedlings when the experiment was first set up, and after one day. A B C D light from all around light from one side light from all around light from one side day 1 (set up) A B C D day 2 Fig. 8.1

19 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (a) The student concluded that the tip of a shoot is needed for growth. Describe the evidence in Fig. 8.1 that supports his conclusion. [2] (b) Compare the appearance of shoots A and B on day 2. [2] (c) Explain how the results of this experiment show that the receptor that is sensitive to light is at the tip of the shoot. [2] (d) Explain why it is useful for a plant to grow towards the light. [2]

20 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 9 (a) Fig. 9.1 shows apparatus that a student used to investigate the electrolysis of sodium chloride solution. R direct current supply Q concentrated sodium chloride solution + – Fig. 9.1 When an electric current flowed through the circuit, gases collected in tubes Q and R. (i) Label the cathode in Fig. 9.1. [1] (ii) The gas in tube Q bleached damp litmus paper. Name the gas which collected in tube Q. [1] (iii) Name the gas which collected in tube R. [1] (iv) During this electrolysis, the pH of the solution increased. Explain why this occurred. [2]

21 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (b) When chlorine gas is bubbled through a colourless solution of potassium iodide, the solution turns dark brown because the element iodine is formed. (i) Name this type of chemical reaction and explain briefly why it has occurred. name of chemical reaction why the reaction occurred [2] (ii) Write a word equation for the reaction. + + [1]

22 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 10 (a) A plate on the back of an electric cooker gives this information. power 5000 W voltage 250 V a.c. frequency 50 Hz Fig. 10.1 (i) Explain what is meant by an a.c. frequency of 50 Hz. [2] (ii) Calculate the current which would flow when the cooker was using 5000 W of power. Use the formula power = voltage x current Show your working. A [1] (b) The manufacturers of the cooker claim that it has an efficiency of 50%. Explain what this means. [2]

23 © UCLES 2009 0654/02/M/J/09 [Turn over For Examiner's Use (c) Explain, in terms of heat transfer, why saucepans used on the cooker are made of aluminium, have wooden handles. [2]

24 © UCLES 2009 0654/02/M/J/09 For Examiner's Use 11 Soybeans (soya beans) provide amino acids, which humans need for growth and repair. (a) (i) Name the type of compound that is formed when amino acids link together into polymer molecules. [1] (ii) Write the chemical symbol of the element that is found in all amino acids, but which is not found in carbohydrates. [1] (b) Soybeans contain soybean oil. This is extracted by crushing the beans and then adding the hydrocarbon solvent, hexane. The oil dissolves in hexane which is then separated from the solution by heating. (i) Suggest why it is possible to remove hexane from the soybean oil by heating the solution. [1] (ii) Hexane is a saturated hydrocarbon. Explain the meaning of the term saturated hydrocarbon. [2] (iii) Hexane molecules contain covalent bonds. Describe briefly, in terms of electrons, what happens when a covalent bond forms between two atoms. [2]

25 © UCLES 2009 0654/02/M/J/09 For Examiner's Use (c) Increasing amounts of soybean oil are being used to produce biodiesel. Biodiesel is an alternative fuel to diesel, obtained from petroleum (crude oil). bio diesel growing soybean plants Fig. 11.1 Burning diesel and biodiesel produces similar amounts of carbon dioxide. However, it is believed that burning biodiesel will cause less increase in the carbon dioxide concentration in the atmosphere. Suggest the reason for this. [2] (d) Biodiesel contains hardly any sulfur compounds. Explain why this is an advantage of biodiesel when compared to diesel. [2]

28 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2009 0654/02/M/J/09 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2009 question paper for the guidance of teachers 0654 CO-ORDINATED SCIENCES 0654/02 Paper 2 (Core Theory), maximum raw mark 100 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2009 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0654 02 © UCLES 2009 1 (a) (i) 5.1 (±0.1) ; [1] (ii) as radiation dose goes up so do incidences of leukaemia/radiation dose and incidences are (directly) proportional ; [1] (iii) radiation burns/radiation sickness/death/genetic mutation ; [1] (b) alpha – stopped by paper etc ; beta – not stopped by paper/only partially stopped by aluminium [2] (c) (i) time taken for half atoms to decay/time taken for count/rate to decrease by half ; [1] (ii) 3 half lives ; 12 days ; [2] [Total: 8] 2 (a) A evaporation ; B condensation ; C transpiration/evaporation ; D precipitation ; [4] (b) less transpiration ; less water vapour in the air ; less rainfall ; more runoff ; more flooding ; [max 2] (c) (i) plasma ; [1] (ii) osmosis ; moves/diffuses, through partially permeable membrane ; ppm. is cell membrane from where there is a lot of water to where there is less/high water potential to low water potential ; [max 3] (d) kills, bacteria/micro-organisms/pathogens ; that might cause illness/example of illness ; [2] [Total: 12]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0654 02 © UCLES 2009 3 (a) a group of atoms ; (covalently) bonded ; [2] (b) the hard water/hardness in A reacted with the soap ; soap precipitated as scum ; less soap available to help washing/soap needed to improve washing ; [3] (c) (i) 11 ; [1] (ii) 2 ; Ca in Group II/20 electrons with e.c. 2.8.8.2/calcium has valency of 2 ; [2] [Total: 8] 4 (a) (i) voltmeter in parallel with lamp ; variable resistor and ammeter in series ; everything else correct ; [3] (ii) to vary current/voltage/potential difference (through/across lamp) ; [1] (iii) R = V/I ; = 5.3 ; (allow in working rather than in table) [2] (iv) filament gets hot ; resistance is not constant ; voltage and current are not directly proportional ; [max 2] (b) damaged outer insulation ; short circuit/risk of shock/risk of fire/death ; [2] [Total: 10] 5 (a) (i) feathers ; beak ; wings ; [max 2] (ii) B reptiles ; C amphibians ; [2] (iii) Rana temporaria ; [1] (iv) webbed feet ; (big surface area) for pushing against water (when swimming) ; eyes near top of head ; to see above water surface ; strong hind legs ; to push against water (when swimming) ; [2]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0654 02 © UCLES 2009 (b) (i) A, because the body temperature does not change ; [1] (ii) mammals ; [1] (iii) good environment for cells ; enzymes have optimum temperature ; idea of affecting rate of (metabolic) reactions ; can be active in all temperatures ; [max 2] (iv) food used to generate heat/keep warm ; in respiration ; [2] [Total: 13] 6 (a) magnesium sulphate ; + hydrogen ; [2] (b) (i) (Expt. 2) shortest time to collect 30 cm3 gas/same volume of gas/OWTTE ; [1] (ii) reduce (acid) temperature ; reduce acid concentration ; decrease surface area of magnesium/use same mass of Mg but larger pieces ; [max 2] (iii) reaction ; is exothermic ; releases (heat) energy ; which is transferred to the flask/surroundings ; [max 2] [Total: 7] 7 (a) (i) working; = 5000 N ; [2] (ii) 15 – 25 N/cm2 ; explanation e.g. uses 50 N/cm2 at 40 m and 10 N/cm2 at 0 m ; [2] (b) momentum = m x v ; = 1.2 x 10 = 12 kg m / s ; [2] (c) (i) any electromagnetic wave etc ; [1] (ii) vibrations at right angles to direction of wave ; (transverse) or vibrations in same direction as wave ; (longitudinal) [1] [Total: 8]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0654 02 © UCLES 2009 8 (a) seedling C/no tip ; (had no tip) and did not grow ; [2] (b) both have grown (taller) ; shoot B has bent towards the light but shoot A has grown straight up ; [2] (c) seedling D/tip covered ; (had its tip covered) and has not grown towards the light ; [2] (d) for photosynthesis ; light is energy source ; plant can grow faster with more light ; [max 2] [Total: 8] 9 (a) (i) electrode connected to negative side of power pack labelled ; [1] (ii) chlorine ; [1] (iii) hydrogen ; [1] (iv) because solution becomes alkaline ; because sodium hydroxide is formed in the solution ; [2] (b) (i) (halogen) displacement/redox ; chlorine is more reactive than iodine ; [2] (ii) chlorine + potassium iodide → potassium chloride + iodine ; [1] [Total: 8] 10 (a) (i) the current alternates/is alternating ; 50 times per second ; [2] (ii) current = 5000 / 250 = 20 A ; [1] (b) efficiency = useful energy out/total energy in ; half energy is wasted ; [2] (c) aluminium is a good conductor of heat ; wood good insulator/heat cannot travel through (and burn hand) ; [2] [Total: 7]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0654 02 © UCLES 2009 11 (a) (i) proteins/peptides/polypeptides ; [1] (ii) N ; [1] (b) (i) hexane has a lower boiling point/is more volatile/evaporates more easily ; [1] (ii) compound of only carbon and hydrogen ; which contains only single (covalent) bonds ; [2] (iii) electrons are shared ; in pairs/one electron from each atom is shared/OWTTE ; reference to full outer shell ; [max 2] (c) (i) biodiesel is a renewable energy source ; a “carbon neutral” energy source ; carbon dioxide produced is removed from the atmosphere by growing (new) soybeans/carbon dioxide is re-used/OWTTE ; by the process of photosynthesis ; [max 2] (ii) sulfur compounds burn to produce SO2/sulfur oxide ; acid rain; these cause damage to buildings/irritate respiratory systems ; extra cost involved in removing sulfur from diesel ; [max 2] [Total: 11]