Cambridge IGCSE Science - Combined 0653 — 2010 May/June Paper 3 · Variant 2

This document consists of 20 printed pages. IB10 06_0653_32/4RP © UCLES 2010 [Turn over *2591061649* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/32 Paper 3 (Extended) May/June 2010 1 hour 15 minutes 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 20. 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 2010 0653/32/M/J/10 For Examiner's Use 1 (a) Fig. 1.1 shows four fruits. P Q R S Fig. 1.1 (i) Give the letters of two fruits which are adapted for wind dispersal. and [1] (ii) Name the part of a flower from which the fruit develops. [1] (iii) Explain the importance of fruits in the life cycle of a plant. [2] (b) Cacao trees produce many pink and white flowers from which the fruits develop. The seeds inside the pods (fruits) are used to make chocolate. Wild cacao trees grow in rainforests in warm, humid climates. Most kinds of trees cultivated by humans, such as rubber trees or oil palms, grow best on cleared land, but cacao trees grow best underneath other rainforest trees. Most cacao trees are grown without the use of fertilisers or pesticides. (i) Suggest how the flowers of the cacao tree are pollinated, giving a reason for your answer. [1]

3 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (ii) Explain why cultivating cacao trees may cause less damage to rainforests than cultivating other trees. [3]

4 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 2 (a) A teacher placed a small piece of potassium into a container filled with chlorine gas. Fig. 2.1 shows what the class observed. clouds of particles made of a white solid container initially full of chlorine gas flames potassium Fig. 2.1 (i) Suggest the name of the white solid formed when potassium and chlorine react. [1] (ii) Fig. 2.2 shows a potassium atom and a chlorine atom. × × × × × × × × × × × × × × × × × potassium atom chlorine atom Fig. 2.2

5 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use Describe and explain, in terms of electronic structures, what happens when potassium and chlorine atoms react with each other. You may draw diagrams in the space below if it helps you to answer the question. [4] (b) Metallic potassium can be produced by electrolysis of molten potassium chloride. In this process, potassium forms at the cathode. (i) Explain why potassium ions travel to the cathode and not the anode during electrolysis. [1] (ii) Describe, in terms of electrons, what happens when potassium ions collide with the surface of the cathode. [2]

6 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 3 (a) Fig. 3.1 shows an astronaut on a space walk. His space suit is designed to stop dangerous electromagnetic radiation from the Sun reaching the astronaut’s body. Fig. 3.1 (i) Name two types of electromagnetic radiation that can harm the body. 1 2 [1] (ii) State one way in which electromagnetic radiation can harm the body. [1] (iii) All electromagnetic waves travel at the same speed. What is the value of this speed? [1] (b) The astronaut has a mass of 96 kg. The gravitational field strength on the Moon is about one sixth of that on the Earth. State the difference, if any, between (i) the mass of the astronaut on the Earth and on the Moon, [1] (ii) the weight of the astronaut on the Earth and on the Moon. [1]

7 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (c) The astronaut stands on the surface of the Moon and drops a ball. The graph in Fig. 3.2 shows the speed of the ball over a period of 1.6 seconds. 2.5 2.0 1.5 1.0 0.5 0 speed / m per s 1.6 0.4 0 0.8 1.2 1.4 0.2 0.6 1.0 time / s Fig. 3.2 (i) On the same graph, sketch a line to show the speed of the same ball if it was dropped on Earth. [1] (ii) Explain your answer to (c)(i). [1]

8 © UCLES 2010 0653/32/M/J/10 For Examiner's Use (d) A rock on the Moon weighs 6 N. The astronaut lifts it up by 2 metres. (i) Calculate the work done on the rock. State the formula that you use and show your working. formula working [2] (ii) If the rock was lifted in 2 seconds, calculate the power used. State the formula that you use and show your working. formula working [2]

9 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use 4 Fig. 4.1 shows a section through a human heart, seen from the front. A B C D Fig. 4.1 (a) (i) Name the type of tissue found in the walls of the heart, as shown in the shaded parts in Fig. 4.1. [1] (ii) Describe how this tissue is supplied with oxygen. [2] (iii) Give the letters of the two labelled blood vessels that contain oxygenated blood. and [1] (b) Plants also have transport systems in which liquids flow through vessels. However, they do not have a pump like the heart. (i) Explain what makes water flow up through the xylem vessels in a plant. [2] (ii) Describe how sugars, made in a plant's leaves, are transported to its roots. [2]

10 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 5 (a) Some fuels are listed below. animal dung coal wood State one reason why coal is an example of a fossil fuel whereas the other two are not. [1] (b) Fig. 5.1 shows a simplified diagram of fractional distillation and catalytic cracking which are both carried out at an oil refinery. Compounds leaving the fractional distillation column at M move into the catalytic cracker. L fractional distillation column M N catalytic cracker strong heat Fig. 5.1 (i) Name the raw material which enters at L. [1] (ii) Describe briefly two ways, other than colour and odour, in which the mixture of compounds at M differs from the mixture of compounds at L. [2] (iii) Describe briefly two ways in which the mixture of compounds at N differs from the mixture of compounds at M. 1 2 [2]

11 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (iv) Some of the compounds in the mixture at N can be used in addition polymerisation. Explain why addition polymers can be made from molecules in the mixture at N but not from molecules in the mixture at M. You may draw a diagram if it helps you to answer this question. [2] (c) A student investigated the combustion products of the liquid fuel ethanol. He observed that a gas and a colourless liquid were produced. (i) The student applied a chemical test to the colourless liquid and found that it was water. Describe a suitable chemical test for water and its result. [2] (ii) Complete the equation below for the combustion of ethanol. C2H6O + → 2CO2 + 3H2O [2]

12 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 6 Fig. 6.1 shows a cube. 2 cm 2 cm 2 cm Fig. 6.1 (a) The mass of the cube is 21.6 g. Calculate the density of the cube. State the formula that you use and show your working. formula working [3] (b) The solid cube is made up of very small particles. Fig. 6.2 shows their arrangement. Fig. 6.2

13 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (i) Complete the diagrams below to show the arrangement of particles in a liquid and in a gas. liquid gas [2] (ii) Explain your answer to (b)(i) in terms of forces between particles. [2] (c) Explain, in terms of particles, why a solid expands when heated. [1] (d) Describe one problem caused by a solid metal expanding when it gets hot. [2]

14 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 7 (a) A student peeled a layer of cells from the inside of an onion bulb. He placed them in a drop of water on a microscope slide and covered them with a coverslip. Fig. 7.1 shows what he saw when viewing the cells through a microscope. Fig. 7.1 (i) The cells in Fig. 7.1 are similar to each other. Give the name for a group of similar cells. [1] (ii) State two ways in which the cells in Fig. 7.1 differ from animal cells. 1 2 [2] (b) The student replaced the water on the slide with a drop of concentrated sugar solution. He waited for five minutes and then looked at the cells through the microscope again. Fig. 7.2 shows what he saw. Fig. 7.2

15 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (i) On Fig. 7.2, label a partially permeable membrane. [1] (ii) Using your knowledge of osmosis, explain what has happened to the cells in Fig. 7.2. [3] (c) Onion cells often contain stores of starch. When a person eats an onion, the starch is digested. Describe how starch is digested in the human alimentary canal. [3]

16 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 8 (a) A student used the apparatus in Fig. 8.1 to investigate the rate of a reaction. piston moves out as gas enters the syringe 0.1 g magnesium gas syringe excess dilute hydrochloric acid bung side-arm test-tube Fig. 8.1 The student dropped the magnesium into the acid contained in the side-arm test-tube and put in the bung. A stopwatch was used to time how long it took for 50 cm3 of gas to collect in the syringe. The student carried out four experiments A, B, C and D, and the results are shown in Table 8.1. Table 8.1 experiment time for 50 cm3 of gas to collect in the gas syringe / seconds A 36 B 18 C 144 D 72 (i) Explain how the results show that experiment B had a higher rate of reaction than experiment A. [1] (ii) The only variable (factor) which was different between the four experiments A, B, C and D was the concentration of the dilute hydrochloric acid. Using the letters A, B, C and D, list the experiments in order of decreasing acid concentration. (highest concentration) (lowest concentration) [1]

17 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (iii) Fig. 8.2 shows a piece of magnesium in a beaker of dilute hydrochloric acid. The hydrogen ions, present in all aqueous acids, are shown by the symbol • . hydrogen ions H+ water magnesium Fig. 8.2 Explain, in terms of ions, why the rate of reaction will change when the concentration of the acid is changed. [3] (b) Magnesium reacts with hydrochloric acid to form magnesium chloride and hydrogen gas. The chemical formula for magnesium chloride is MgCl2. Use the Periodic Table on page 20 to calculate the relative formula mass of magnesium chloride. Show your working. [2]

18 © UCLES 2010 0653/32/M/J/10 For Examiner's Use 9 (a) Fig. 9.1 shows a teacher with a torch (flash light). He switches the torch on and points it at the mirror. Fig. 9.1 A ray of light from the torch reflects off the mirror. Use a ruler to draw a ray of light (i) from the torch to the mirror, (ii) reflecting off the mirror. [2] (b) A torch contains two cells providing a total voltage of 3.0 V across the lamp. When the torch is lit, the current flowing through the lamp is 0.3 A. (i) Calculate the resistance of the lamp. State the formula that you use and show your working. formula working [2]

19 © UCLES 2010 0653/32/M/J/10 [Turn over For Examiner's Use (ii) To measure the current through the lamp and the voltage across the lamp, the student set up the circuit in Fig. 9.2. A V Fig. 9.2 The student sketched a graph of current against voltage for the lamp. This is shown in Fig. 9.3. current voltage Fig. 9.3 Does the lamp obey Ohms Law? Explain your answer. [2]

20 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 2010 0653/32/M/J/10 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 2010 question paper for the guidance of teachers 0653 COMBINED SCIENCE 0653/32 Paper 32 (Extended Theory), maximum raw mark 80 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 2010 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 2010 0653 32 © UCLES 2010 1 (a) (i) Q and R ; [1] (ii) ovary ; [1] (iii) they contain / protect, seeds / implied ; disperse seeds / specific mechanism ; so plant can spread to new areas / reduces competition with parent plant ; [max 2] (b) (i) insects / birds / bats / animals / reason: coloured (petals attract) ; [1] (ii) does not require (all) forest trees to be cut down ; so less likelihood of habitat loss (for animals) ; so less chance of soil erosion ; so less chance of reduction in rainfall ; so less reduction in species diversity; does not use, fertilisers / pesticides ; fertilisers might mean some plants outgrow native ones ; pesticides might kill other species ; [max 3] [Total: 8] 2 (a) (i) potassium chloride ; [1] (ii) outer electron lost from K atom ; outer shell of chlorine atom fills/gains one electron ; K forms positive ion / K+ / Cl forms negative ion / Cl – ; reference to ions having filled outer shells ; reference to KCl have greater stability / lower energy than uncombined atoms ; reference to ions attracting (to form KCl) ; [max 4] (b) (i) K ion is positive, cathode is negative / opposite charges attract ; [1] (ii) ions gain electron(s) ; (each ion gains) one electron / is discharged / becomes an atom ; [2] (K+ + e- → K = 2 marks) [Total: 8]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 32 © UCLES 2010 3 (a) (i) IR / UV / X Rays / gamma / microwave ; (1 mark for two correct answers from list) [1] (ii) burns skin ; damages eyes / cataracts ; reference to cancer ; (ionisation leading to) mutation / DNA damage / cell damage ; [1] (iii) 3 × 108 m / s ; [1] (any correct value with unit) (b) (i) no difference ; [1] (ii) weight is 6 times greater on Earth (accept answers showing numbers) ; [1] i.e. weight on Earth is 960 N weight on moon is 160 N (reject weight Earth is 96 kg and on moon 16 kg) (c) (i) line higher ; [1] (allow curves arising from effects of air resistance) (ii) gravity / force / acceleration is greater ; [1] (d) (i) (work =) force / weight × distance ; = 6 × 2 = 12 J ; [2] (ii) power = work (energy) / time ; = 12 / 2 = 6W (or J / s) ; [2] (allow ecf from (i)) [Total: 11]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 32 © UCLES 2010 4 (a) (i) (cardiac) muscle ; [1] (ii) coronary arteries ; ref to red blood cells ; ref to haemoglobin ; diffusion out of capillaries / blood vessels into tissue ; [max 2] (reject by diffusion alone) (iii) C and D ; [1] (b) (i) (evapo) transpiration / loss of water from leaves ; (transpiration) reduces pressure / reduces water potential ; water moves down pressure gradient / from high to low pressure / from high to low water potential ; [max 2] (ii) in phloem ; as sucrose ; in solution ; [max 2] [Total: 8] 5 (a) (coal has) taken much longer to form / has required action of pressure / heat / bacterial action / formed underground / under rocks / within the Earth ; been made from dead plants ; [max 1] (b) (i) crude oil / petroleum ; [1] (ii) (at M) mixture is simpler / has larger proportion of smaller molecules ; is less viscous / more flammable / less dense ; has lower boiling range / point / is at a lower temperature ; [max 2] (iii) (at N) mixture contains smaller molecules / lower boiling point / lower viscosity / lower density ; mixture contains (much greater proportion of) unsaturated compounds ; [2] (iv) description of (addition) polymerisation / polymer reasonably shown by diagram ; reference to unsaturated molecules reacting or shown in diagram ; no (significant amounts of) unsaturated compounds at M ; [max 2] (c) (i) cobalt chloride paper ; blue to pink ; anhydrous / white copper sulfate ; (white to) blue ; [2] (ii) + 3O2 (formula and balance) ;; [2] [Total: 12]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 32 © UCLES 2010 6 (a) volume = 8 cm3 ; density = mass / volume ; 21.6 / 8 = 2.7 g / cm3 ; [3] (b) (i) liquid most particles touching and irregular arrangement ; gas – spaces between particles and irregular arrangement ; [2] (ii) reference to forces of attraction ; a comparative statement showing forces greater in liquids ; [2] (c) particles slightly further apart / vibrate more and so require more space ; [1] (d) problem e.g. bridges / rail tracks / rulers expand ; amplification – can be consequence e.g. causes damage / become inaccurate ; or solution e.g. gaps / rubber filled gaps are included ; [max 2] [Total: 10]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 32 © UCLES 2010 7 (a) (i) tissue ; [1] (ii) they have cell walls ; they have, vacuoles / cell sap ; [2] (b) (i) p.p.m. [1] (ii) water has gone out of cells ; because concentration of solution outside cell is greater than inside or because 'concentration' of water is greater inside cells than outside or because water potential is greater inside cells than outside ; e.g. water moves from low concentration to high concentration / but water moves from high to low – must specify water concentration (so) volume of, cytoplasm / vacuole, has decreased or cell contents have shrunk ; cell membrane has pulled away from cell wall ; ref to plasmolysis ; [max 3] (c) amylase ; in, saliva / pancreatic juice ; breaks down starch to sugar ; in, mouth / duodenum / small intestine ; [max 3] [Total: 10]

Page 7 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 32 © UCLES 2010 8 (a) (i) (in B) it took less time to (collect the same amount / volume of gas) ; [1] (ii) B (highest) A D C (lowest) ; [1] (iii) (may do this generally or in terms of increased or decreased conc.) (when concentration changes) different number of ions present / per unit volume / near the magnesium ; ions are in (constant random) motion / collide with magnesium ; different numbers of ions mean different collision frequency / OWTTE ; rate of reaction affected by collision frequency ; [max 3] (reference to numbers of particles = 1 mark reference to motion and or collisions = 1 mark linking collision to rate = 1 mark) (b) 24 + (35.5 × 2) ; = 95 ; [2] (e.c.f. from use of proton numbers, so 20 scores 1 mark) [Total: 7] 9 (a) straight lines with correct arrows ; angles approx correct ; [2] (b) (i) (resistance =) PD / current ; also V ÷ I / voltage ÷ I = 3.0 / 0.3 = 10 Ω ; [2] (ii) (no) not a straight line / not (directly) proportional / current and voltage not proportional ; resistance increases with voltage / not a constant ; [2] [Total: 6]