Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2013 Oct/Nov Paper 3 · Variant 3

This document consists of 30 printed pages and 2 blank pages. IB13 11_0654_33/3RP © UCLES 2013 [Turn over *4802736772* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/33 Paper 3 (Extended) October/November 2013 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 pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. Electronic calculators may be used. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 32. 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 2013 0654/33/O/N/13 For Examiner's Use 1 Fig. 1.1 shows a root hair cell. Fig. 1.1 (a) Use the letters A, B and C to label these parts of the root hair cell in Fig. 1.1. A a partially permeable membrane B the part that contains DNA C a structure that is not present in animal cells [3] (b) Describe how the structure of the root hair cell helps it to carry out its functions. [3]

3 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (c) Fig. 1.2 shows part of a plant stem from which the outer layer has been removed. xylem phloem Fig. 1.2 Explain why this treatment would cause the roots of the plant to die. [3]

4 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 2 (a) Table 2.1 shows information about some chemical elements and their positions in the Periodic Table. Table 2.1 element group number in the Periodic Table oxygen 6 calcium 2 lithium 1 sulfur 6 fluorine 7 Select two elements from Table 2.1 whose atoms form covalent bonds with each other and explain your answer. and explanation [2]

5 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (b) Fig. 2.1 shows the electron arrangement in an atom of phosphorus. P Fig. 2.1 Phosphorus and hydrogen bond together to form the compound phosphine. One molecule of phosphine contains one atom of phosphorus. Predict and explain the chemical formula of one molecule of phosphine. You may wish to draw a diagram to help you to answer this question. predicted formula explanation [3]

6 © UCLES 2013 0654/33/O/N/13 For Examiner's Use (c) A student added excess acidified barium chloride solution to a solution of magnesium sulfate. Fig. 2.2 shows the procedure followed. solution W precipitate of barium sulfate solution of magnesium sulfate acidified barium chloride solution Fig. 2.2 A white precipitate of barium sulfate was produced. The chemical equation for the reaction is BaCl2(aq) + MgSO4(aq) BaSO4(s) + MgCl2(aq) (i) State three ions that are dissolved in solution W in Fig. 2.2. 1 2 3 [1] (ii) He used 50.0 cm3 of magnesium sulfate solution of concentration 0.75 mol / dm3. Calculate the number of moles of magnesium sulfate used by the student. Show your working. moles [2]

7 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (iii) State the number of moles of barium sulfate precipitate that were produced by the reaction. moles [1] (iv) Use the Periodic Table on page 32 to calculate the mass of barium sulfate that formed in the reaction. Show your working. g [2]

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9 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use 3 (a) Fig. 3.1 shows a circuit used to measure the current passing through a resistor when the voltage across it is changed. A V Fig. 3.1 Complete the sentences below using suitable words. When the voltage across the resistor is reduced, the current through the resistor . When the voltage of the supply is reduced, the voltage across the resistor . [1] (b) The resistance of a piece of wire depends on a number of variables such as the temperature of the wire and the material from which it is made. State two other factors which affect the resistance of a piece of wire. 1 2 [2]

10 © UCLES 2013 0654/33/O/N/13 For Examiner's Use (c) Fig. 3.2 shows a circuit used to power a small motor. A V M Fig. 3.2 The voltage across the motor is 3 V. The current through the motor is 0.6 A. (i) Calculate the power input to the motor. State the formula that you use, show your working and state the unit of your answer. formula working unit [2] (ii) The motor is able to lift a load of 40 N through 1.2 m in 36 seconds. Calculate the power output of the motor. State the formula that you use, show your working and state the unit of your answer. formula working unit [3]

11 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (iii) Explain why there is a difference between your answers to (i) and (ii). [1] (iv) Calculate the efficiency of the motor. Show your working. [2] (d) An electric current in a wire is a flow of electrons. β(beta)-radiation also consists of electrons. (i) State the name of the sign of the charge on an electron. [1] (ii) α(alpha)–radiation moves in the opposite direction to β–radiation in an electrical field. γ(gamma)–radiation passes through an electrical field without deviation. Explain these two statements. [2]

12 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 4 Soya beans are an important crop in Brazil. Soya beans can be used to make soya 'milk', which can be made into yoghurt. (a) To make yoghurt, microorganisms are added to soya milk. The milk is then kept warm for several hours. (i) State the type of microorganism that is added to milk to make yoghurt. [1] (ii) Explain why the milk is kept warm for several hours. [2] (b) Researchers in Brazil investigated whether adding sugar to the soya milk affected the yoghurt that was produced. They added sugar to one batch of soya milk, but not to another. They measured the percentage of lactic acid in each batch of yoghurt at the start, and after 4, 5, 6 and 7 hours. Fig. 4.1 shows their results. 0 1 2 3 time / hours 4 5 6 7 0.5 0.4 0.3 0.2 0.1 0 percentage of lactic acid no added sugar no added sugar no added sugar with added sugar with added sugar with added sugar Fig. 4.1

13 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (i) Describe the change in lactic acid concentration during the fermentation of the yoghurt with no added sugar. [2] (ii) Compare the concentration of lactic acid when sugar is added with the concentration of lactic acid when no sugar is added. State the difference and explain it. [2] (c) Large areas of rainforest have been cleared in Brazil, to provide more land for growing soya beans. Explain how cutting down the rainforest can harm the environment. [4]

14 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 5 A student carried out experiments to investigate the differences in reactivity of some elements. (a) Fig. 5.1 shows what the student observed when he removed an iron nail that had been placed into a solution of copper sulfate for a short time. copper sulfate solution iron nail orange layer sticking to the surface of the nail Fig. 5.1 The student correctly concluded that a layer of copper had formed on the surface of the nail. Explain, in terms of electron transfer, how the reaction is an example of redox (reduction and oxidation). [2] (b) Fig. 5.2 shows apparatus used by the student to investigate the reaction between different metals and steam, H2O(g). small test-tube initially filled with water gas collecting water heat steam metal reaction tube delivery tube Fig. 5.2 The student carried out experiments using two metals, P and Q. His observations are shown in Table 5.1.

15 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use Table 5.1 metal observation in reaction tube observation in small test-tube P no reaction no gas produced Q • rapid exothermic reaction • white powdery solid produced gas G collects (i) State the element which combined with metal Q to form the white powdery solid. [1] (ii) Name the gas G. [1] (iii) Use the observations to compare the reactivities of the three elements, P, Q and gas G. Explain your answer. most reactive least reactive explanation [3] (c) Mild steel is an alloy that contains mainly iron. Mild steel will rust unless it is protected. State and explain how a covering of metallic zinc provides sacrificial protection of steel from rusting. [4]

16 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 6 (a) (i) Fig. 6.1 gives information about the uses of different types of electromagnetic waves and their effects on living tissue. Draw lines to link each electromagnetic wave with its effect on living tissue and its use. One has been completed as an example. screening luggage security marking satellite communication seeing uses X-rays microwave ultra violet visible light type of radiation activates sensitive cells in retina kills cancerous cells heats water in tissues causes tanning of skin effects on tissue Fig. 6.1 [4] (ii) State one property that is the same for all electromagnetic waves. [1] (b) Infra-red radiation is the part of the electromagnetic spectrum often involved in heat transfer by radiation. A student carried out an experiment to find out the type of surface that was the best emitter of radiation. She set up the apparatus shown in Fig. 6.2 and measured the temperature of the water in the flasks every minute for 20 minutes. flask A clear glass surface flask B surface painted black flask C surface painted silver thermometers Fig. 6.2

17 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use Her results are shown in Fig. 6.3. 0 5 10 15 20 25 100 90 80 70 60 50 40 30 20 10 0 time / mins temp / °C flask A flask C flask B Fig. 6.3 (i) From the graphs identify, with a reason, the flask that cools most rapidly. [1] (ii) Suggest why the flask you identified in (i) cooled more rapidly than the others [1] (iii) State two variables which the student needed to keep constant during her experiment. 1 2 [1]

18 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 7 Ball pythons (royal pythons) are snakes that are kept as pets in many parts of the world. The colour of a ball python is determined by its genes. Gene A has two alleles, AN and AB. Neither allele is dominant or recessive. Table 7.1 shows the three possible genotypes and colours arising from this gene. Table 7.1 genotype colour AN AN normal AN AB cinnamon AB AB black (a) Suggest why the alleles of this gene are not shown using a single capital letter and its small letter, e.g. A and a. [1] (b) State the correct biological term for the visible appearance produced by the genotype, in this case the colour of the snake. [1]

19 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (c) People try to breed pythons with unusual colours, because they are worth more money. Use information from Table 7.1 to construct a genetic diagram to explain how a breeder can produce cinnamon offspring from a normal snake and a cinnamon snake. [4] (d) A breeder has several normal snakes, no cinnamon snakes and one black snake. Suggest how she can breed more black snakes. [2]

20 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 8 Dilute nitric acid reacts with calcium carbonate according to the equation. nitric acid calcium carbonate calcium nitrate carbon dioxide + + water + (a) Calcium nitrate contains calcium ions and nitrate ions. Calcium is an element in Group 2 of the Periodic Table and nitrate ions have the formula NO3 -. Deduce the chemical formula of calcium nitrate. Show how you obtained your answer. formula of calcium nitrate [3] (b) A student carried out an investigation into the way that the rate of the reaction between calcium carbonate and nitric acid changed when he varied the concentration of the nitric acid. Fig. 8.1 shows the apparatus the student used to measure the rate of reaction. thermometer side-arm test-tube excess dilute nitric acid calcium carbonate controlled temperature water bath piston of the syringe slides out as gas enters gas syringe Fig. 8.1

21 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use The student measured the rate of reaction by finding the time it took for the gas syringe to fill with gas. The student measured the rate of reaction using five different concentrations of nitric acid. Fig. 8.2 shows the student’s results as a graph of rate of reaction against acid concentration. concentration of nitric acid rate of reaction 0 0 Fig. 8.2 (i) Describe the relationship shown by the graph. [2] (ii) Explain these results in terms of particle collisions. [2] (iii) Explain why the temperature of the reacting mixture needs to be kept constant. [2]

22 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 9 Fig. 9.1 shows a solar-powered golf cart used to carry golfers around a golf course. Fig. 9.1 (a) As the cart moves around the course, the motion of the cart is measured. Fig. 9.2 shows a distance / time graph for a small part of the journey lasting 60 seconds. 100 80 60 40 20 0 0 10 20 30 time / s 40 50 60 distance / m A B C D E F E D C B A Fig. 9.2

23 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (i) Show that the speed of the cart between B and C is 5 m / s. Show your working in the space. [1] (ii) The mass of the cart is 400 kg. Calculate the kinetic energy of the cart between B and C. State the formula that you use, show your working and state the unit of your answer. formula working unit [2] (iii) Describe the motion of the cart between D and E. [1] (iv) Later in the journey, the cart accelerates from 1 m / s to 3 m / s in 5 seconds. Calculate the acceleration of the cart. State the formula that you use, show your working and state the unit of your answer. formula working unit [2]

24 © UCLES 2013 0654/33/O/N/13 For Examiner's Use (b) (i) During the cart’s journey, the temperature of the air in the tyres increases by 15 °C. The volume of the air in the tyre remains the same. Explain in terms of particles why the pressure of the air in the tyre increases when this happens. [1] (ii) Sometimes the golfer’s hands begin to sweat. Explain in terms of particles how sweating cools his hands by evaporation. [2] (iii) During evaporation, water changes state from liquid to gas. Complete the diagrams to show the arrangement of particles in a liquid and in a gas. liquid gas [2]

25 © UCLES 2013 0654/33/O/N/13 [Turn over Please turn over for Question 10.

26 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 10 Fig. 10.1 shows a section through an eye. Fig. 10.1 (a) Complete the sentences to describe how the eye focuses on a nearby object, after it has been looking at a distant object. Light from a nearby object is diverging than light from a distant object. To focus on a nearby object, the muscles . This the tension on the suspensory ligament, which the focal length of the lens. [5] (b) On Fig. 10.1, write the letter F to show where the rays of light focused by the lens form an image. [1]

27 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (c) When bright light shines onto the eye, the size of the pupil quickly decreases. This is a reflex action. (i) Explain what is meant by the term reflex action. [1] (ii) Outline the role of each of the following structures in this reflex action. sensory neurone motor neurone [3] (d) Most parts of the body are supplied with nutrients and oxygen by blood flowing through capillaries. The cornea and lens of the eye do not contain blood capillaries. They obtain nutrients and oxygen from the aqueous humour and vitreous humour. (i) Suggest why these parts of the eye do not contain blood capillaries. [1] (ii) Explain why all the living cells in the eye require oxygen. [2]

28 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 11 Gasoline and diesel are liquid mixtures of hydrocarbons used as fuels. Fig. 11.1 shows the structure of a typical molecule in gasoline. C H H H C C H H C H H C H C H H H H C H H C H H H H Fig. 11.1 (a) (i) State the chemical formula of the molecule in Fig. 11.1. [1] (ii) Explain briefly why a molecule like the one in Fig. 11.1 is classified as an alkane molecule. [1] (b) Table 11.1 shows some properties of gasoline and diesel. Table 11.1 fuel temperature range over which the fuel boils / °C viscosity (how easily the liquid flows) gasoline 40 to 205 runny (flows easily) diesel 250 to 350 less runny (i) Explain, in terms of molecules and forces, why the properties of these fuels are different. [2]

29 © UCLES 2013 0654/33/O/N/13 [Turn over For Examiner's Use (ii) Decane, C10H22, boils at a temperature of 174 °C. Suggest why gasoline boils over a range of temperatures whereas decane boils at a single temperature. [1] (c) Ethene, C2H4, is an unsaturated hydrocarbon. (i) Describe a chemical test and its result which would show that ethene is unsaturated. test result [2] (ii) Ethene can be made to undergo complete combustion in an exothermic reaction with oxygen, O2. Deduce the balanced symbol equation for this reaction. [2]

30 © UCLES 2013 0654/33/O/N/13 For Examiner's Use 12 (a) Fig. 12.1 shows a light ray entering an optical fibre. optical fibre light ray Fig. 12.1 The light ray travels all the way through the optical fibre. Explain why the light ray is able to stay inside the optical fibre. You may draw on the diagram if it helps your answer. [3] (b) Fig. 12.2 shows an observer’s eye looking at an object in a mirror. observer’s eye object mirror Fig. 12.2 (i) On Fig. 12.2 complete the ray diagram to show how the two rays of light from the object enter the eye of the observer. [1] (ii) On Fig. 12.2 show how the observer sees rays of light which appear to come from the image behind the mirror. Label the position of the image with an X. [2]

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32 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 2013 0654/33/O/N/13 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

CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2013 series 0654 CO-ORDINATED SCIENCES 0654/33 Paper 3 (Extended Theory), maximum raw mark 120 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 should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2013 series for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level components. www.XtremePapers.com

Page 2 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 1 (a) A to cell membrane / membrane round vacuole ; B to nucleus ; C to cell wall / large vacuole ; [3] (b) functions are uptake of water / mineral ions ; partially permeable membrane allows (water to enter by) osmosis ; has large surface area ; increases (rate of) uptake (of water / mineral ions) ; [max 3] (c) phloem has been removed / prevents phloem transport ; phloem transfers substances from leaves (to roots) ; reference to sucrose ; roots have no sucrose / short of nutrients ; [max 3] [Total: 9] 2 (a) any two from oxygen, sulfur, fluorine ; both non-metals ; [2] (b) PH3 ; hydrogen atoms have electron configuration of 1 / need to gain 1 electron for filled outer shell ; atoms share (pairs) of electrons ; so that each has filled shells ; [max 3] (c) (i) any three from barium, magnesium, chloride, hydrogen ; [1] (ii) 0.75 × 50.0 ; (0.75 × 50.0) ÷ 1000 = 0.0375 or 0.038 ; [2] (iii) 0.0375 or 0.038 ; [1] (iv) Mr barium sulfate = 233 ; 0.0375 × 233 = 8.74 (g) ; [2] [Total: 11]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 3 (a) decreases and decreases ; [1] (b) length ; diameter / cross-sectional area / thickness / width ; [2] (c) (i) (power =) voltage × current ; = 3 × 0.6 = 1.8 W ; [2] (ii) work = force × distance and (power =) work/time or (P=)Fx/t ; = 40 × 1.2/36 ; 1.3(3) W ; [3] (iii) energy lost / wasted (as heat / sound) ; [1] (iv) efficiency = 1.33/1.8 × 100 ; 73.88% (allow 0.74 or 0.72) ; [2] (d) (i) negative ; [1] (ii) alpha is positive / opposite charge to beta ; gamma has no charge ; [2] [Total: 14] 4 (a) (i) bacteria / Lactobacillus / Streptococcus ; [1] (ii) to speed up the production of yoghurt ; microorganisms work faster (at higher temperature) ; reproduction rate of microorganisms is faster ; [max 2] (b) (i) increased ; use of data e.g. from 0.15% to 0.31% ; description of variation in rate e.g. rate of increase slowed after six hours ; [max 2] (ii) added sugar increases the amount of lactic acid / use of data to illustrate this ; microorganisms convert sugar to lactic acid ; more sugar increases rate of production of lactic acid ; [2]

Page 4 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 (c) area too small to support populations / reduction in biodiversity / extinction / species become endangered / lack of opportunity to find new medicines ; due to reduction of habitat ; flooding / leaching of minerals ; due to rain falling directly on soil / lack of protection of tree canopy / increased runoff ; soil erosion ; due to lack of tree roots ; drought ; due to lack of transpiration by trees to form rain (leading to desertification) ; CO2 levels in the atmosphere increase ; due to fewer trees to photosynthesise / less photosynthesis to remove carbon dioxide ; also due to burning trees produce CO2 / rotting trees produce CO2 by respiration of microbes ; carbon dioxide reduces rate of loss of heat from the Earth’s surface / increases global warming ; due to trapping long-wave radiation / infra-red / heat / thermal energy / being a greenhouse gas ; [max 4] [Total: 11] 5 (a) oxidation is loss of electrons / reduction is gain in electrons ; iron atoms have lost electrons / copper ions have gained electrons ; [max 2] (b) (i) oxygen ; [1] (ii) hydrogen ; [1] (iii) Q G P ; Q more reactive than G because able to remove oxygen from it / owtte ; P less reactive than G since unable to separate oxygen from it / owtte ; [3] (c) air / oxygen and water react with iron / steel to form rust ; zinc provides barrier between iron and environment ; (if zinc layer damaged) zinc corrodes / oxidises rather than iron / owtte ; because zinc more reactive than iron ; [4] [Total: 11]

Page 5 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 6 (a) (i) links in the left column: 3 correct = 2 marks and 1 correct = 1 mark ;; links in the right column: 3 correct = 2 marks and 1 correct = 1 mark ;; [4] (ii) (wave) speed ; transverse waves ; do not require a medium ; [max1] (b) (i) flask B because temperature drops most (over a period of time) ; [1] (ii) black surfaces are good emitters of radiation; [1] (iii) need two answers volume of water shape / size of flask starting temperature of water / ambient temperature ; [1] [Total: 8] 7 (a) neither allele is, dominant / recessive ; [1] (b) phenotype ; [1] (c) (parents' genotypes) ANAN and ANAB ; gametes AN from one parent, AN and AB from the other ; offspring genotypes ANAN and ANAB ; relates genotypes to phenotypes / equal numbers of normal and cinnamon ; [4] (d) breed black snake with a normal snake (to give cinnamon offspring) ; then breed cinnamon offspring, with each other / with the black snake ; [2] [Total: 8] uses type of radiation effects on tissue screening luggage security marking satellite communication seeing activates sensitive cells in retina kills cancerous cells heats water in tissues causes tanning of skin X-rays microwave ultra violet visible light

Page 6 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 8 (a) calcium ions are Ca2+ ; reference to need for charge balance (so two nitrate ions required) ; formula is Ca(NO3)2 ; [3] (b) (i) the greater the acid concentration the higher the rate ; reference to direct proportionality ; [2] (ii) reference to reaction occurring as the result of particle collisions ; higher concentration means higher frequency / probability of collision ; [2] (iii) temperature affects rate of reaction ; so control needed so rate investigation data is valid / reference to fair test ; additional collision theory detail related to rate ; [max 2] [Total: 9] 9 (a) (i) 50/10 (= 5 m / s) ; 20–10 (working could be on graph) [1] (ii) (KE =) ½ mv2; = ½ × 400 × 5 × 5 = 5000 J ; [2] (iii) not moving ; [1] (iv) (acceleration =) change in speed / time ; = 2/5 = 0.4 m / s2 ; [2] (b) (i) particles move faster / have more energy, so more frequent collisions with tyre (wall) ; particles move faster / have more energy, so more forceful collisions with tyre (wall) ; [max 1] (ii) heat transferred from body to sweat / heat absorbed by sweat from athlete’s body / heat energy in body reduced by sweating ; kinetic energy of water molecules increases / water molecules move faster ; faster moving / more energetic (water) molecules escape / leave the surface / water (sweat) molecules turn to gas / vapour ; reference to break bonds / break forces of attraction between molecules ; (KE) / energy of (remaining) water molecules (in sweat) decreases ; [max 2] (iii) liquid – most particles touching, irregular arrangement, particles of similar size ; gas – particles far apart, irregular arrangement, particles of similar size ; [2] [Total: 11]

Page 7 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 10 (a) more / further ; ciliary ; contract / shorten ; decreases ; decreases ; [5] (b) F on retina ; [1] (c) (i) fast / automatic, response to a stimulus ; [1] (ii) (either) transmits nerve impulse ; (sensory neurone) from retina, to brain ; (motor neurone) from brain to muscle (in iris) / effector ; [3] (d) (i) so that light can pass through them / blood would absorb light ; [1] (ii) for respiration ; for release of energy ; ref. to use of energy, e.g. protein synthesis, cell division, cell contraction, passage of nerve impulses ; [max 2] [Total: 13] 11 (a) (i) C8H18 ; [1] (ii) it is a hydrocarbon containing only single bonds / a saturated hydrocarbon ; [1] (b) (i) molecules in gasoline (on average) are smaller / lighter ; so (attractive) forces between molecules in gasoline are lower ; so less energy needed to separate molecules (in gasoline) ; so are less entangled (than in diesel) ; [max 2] (ii) gasoline is a mixture / not a single compound / different compounds in gasoline all have different boiling points ; [1] (c) (i) bromine / bromine water / potassium permanganate ; changes from orange to colourless / purple to colourless ; [2] (ii) C2H4 + 3O2 → 2CO2 + 2H2O ;; [2] [all formulae then look for balanced] [Total: 9]

Page 8 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 33 © Cambridge International Examinations 2013 12 (a) waves are reflected along fibre / by reflection ; total internal (reflection) ; angle (of incidence) is greater than critical angle ; (a well-drawn diagram of an internally reflecting ray with accurate angles of incidence and reflection can be awarded the first two marking points) [3] (b) (i) two rays reflected at the mirror entering the eye and angles approx. correct ; [1] (ii) two lines drawn back from the mirror locating X ; X labelled in correct position ; [2] [Total: 6]