Cambridge IGCSE Science - Combined 0653 — 2010 May/June Paper 3 · Variant 1

This document consists of 24 printed pages. IB10 06_0653_31/4RP © UCLES 2010 [Turn over *6686015037* 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 0653/31 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 24. 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 0653/31/M/J/10 For Examiner's Use 1 Fig. 1.1 shows some of the animals and plants that live in or close to a pond. water vole heron water snail bream pike insect larva not to scale pond weed Fig. 1.1 (a) Give the correct term for each of the following. all the animals and plants that live in and around the pond all the living things, and their environment, interacting with each other [2] (b) The pond weed is a producer. Water snails and water voles are primary consumers. The heron and pike are secondary consumers. Draw a food web that includes only these five organisms. [3]

3 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (c) The pond is at the bottom of a sloping field which was ploughed. During very heavy rain, a lot of soil from the field was washed into the pond. It made the water cloudy, and stopped the light from reaching the leaves of the water plants, so that the plants died. After a while, the fish and other animals also died. (i) Give two reasons why the fish and other animals died. 1 2 [2] (ii) Suggest one way in which the farmer could stop the soil erosion from the field. [1]

4 © UCLES 2010 0653/31/M/J/10 For Examiner's Use 2 (a) Fig. 2.1 shows a bicycle with a front lamp and a rear lamp powered by a battery. Fig. 2.1 Fig. 2.2 shows how the lamps are connected. front lamp rear lamp Fig. 2.2 (i) What name is given to this type of circuit? [1] (ii) The resistance of each lamp in the circuit is 4 Ω. Calculate the combined resistance of the two lamps. State the formula that you use and show your working. formula working [3]

5 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (b) Fig. 2.3 shows a metal nut on a bicycle wheel which is difficult to unscrew. Fig. 2.3 Explain why a long spanner is better than a short spanner to unscrew the nut. [2] (c) As the bicycle moves along the road at 4 m/s, the brakes are suddenly applied. The bicycle comes to a stop after 10 m. The average frictional force stopping the bicycle is 250 N. As the bicycle slows down, work is done. Calculate the work done as the bicycle slows down from 4 m/s to a stop. State the formula that you use and show your working. formula working [2]

6 © UCLES 2010 0653/31/M/J/10 For Examiner's Use 3 Aluminium, iron and sodium are metallic elements. Aluminium and iron are widely used, but no useful objects can be made out of metallic sodium. aluminium alloys are used in aircraft iron is used to make steel for cars (a) Use your knowledge of the alkali metals to state one reason why no useful objects can be made out of metallic sodium. [1] (b) The diagram in Fig. 3.1 shows a cross section through a blast furnace in which iron is extracted from iron oxide. Symbolic equations for three important chemical reactions which occur in the blast furnace are also shown in Fig. 3.1. One of these equations is not balanced. hot air molten iron raw materials including iron oxide and carbon Fe2O3 + CO
2Fe + CO2 CO2 + C
2CO C + O2
CO2 Fig. 3.1 (i) Balance the incorrect equation in Fig. 3.1 by writing the required numbers in the equation on the diagram. [1]

7 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (ii) The three equations in Fig. 3.1 all represent redox reactions. State two substances shown in Fig. 3.1 which have been reduced. Explain your answer briefly. [2] (c) Aluminium is produced from aluminium oxide using electrolysis as shown in Fig. 3.2. – + molten aluminium molten electrolyte containing aluminium oxide carbon cathode carbon anode Fig. 3.2 (i) The lining of the apparatus acts as the cathode in this process. Describe what happens to aluminium ions when they meet the cathode surface. [2] (ii) Explain why aluminium cannot be extracted in a blast furnace in the same way as iron. [2]

8 © UCLES 2010 0653/31/M/J/10 For Examiner's Use (iii) The chemical formula of aluminium oxide is Al2O3 and the electrical charge of an oxide ion is -2. Deduce the electrical charge of an aluminium ion. Explain your answer. [2]

9 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use 4 Fig. 4.1 shows samples of three of the elements in Group VII (Group 7) of the Periodic Table. X Y Z Fig. 4.1 (a) The elements in Fig. 4.1 are at the same temperature. One element is a solid, one is a liquid and one is a gas. (i) State which element, X, Y or Z, has the highest melting point. [1] (ii) Suggest the names of the elements, X, Y and Z. X Y Z [1] (b) An atom of fluorine has a proton (atomic) number of 9 and a nucleon (mass) number of 19. (i) State the number of neutrons in one atom of fluorine. [1] (ii) Calculate the relative molecular mass of a fluorine molecule. [1]

10 © UCLES 2010 0653/31/M/J/10 For Examiner's Use (c) Hydrogen chloride gas may be produced by combining the gases hydrogen and chlorine. (i) Fig. 4.2 shows the chemical bonding in hydrogen and chlorine molecules. In the space in Fig. 4.2 draw a similar diagram to show the bonding in one molecule of hydrogen chloride. H H hydrogen molecule × × × × × × Cl × × × × × × × × Cl chlorine molecule hydrogen chloride molecule Fig. 4.2 [2] (ii) Hydrochloric acid is produced when hydrogen chloride gas reacts with water. Write the symbol and electrical charge of an ion which forms in the mixture when hydrogen chloride gas reacts with water. [1]

11 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (d) A student is asked to try and produce some bromine by mixing two solutions chosen from the list below. potassium bromide potassium chloride potassium iodide chlorine iodine When the student mixed her chosen solutions, she successfully produced bromine. (i) State which solutions the student chose. [1] (ii) Explain your answer to (i). [1]

12 © UCLES 2010 0653/31/M/J/10 For Examiner's Use 5 An investigation was carried out in Tamil Nadu, India, into the best conditions for growing tomatoes. The tomato plants were grown in unheated glasshouses or outside. Netting was used to provide shade in one of the glasshouses. glasshouse A glasshouse B outside no shade all four side walls shaded with netting no shade In each glasshouse, and outside, the mean temperature in each month between January and October was measured. Fig. 5.1 shows the results. 44 42 40 38 36 34 32 30 28 Jan Feb Mar Apr May Jun Jul Aug Sep Oct mean temperature / °C month glasshouse A glasshouse B outside Fig. 5.1 (a) State the month in which the highest mean temperature was reached in glasshouse A, outside. [1]

13 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (b) Light from the Sun passes through the glass of the glasshouse, into the air inside. The soil and other surfaces in the glasshouse re-emit some of this radiation as longer wavelength, infra-red, radiation. Some of this radiation cannot pass through glass. (i) Use this information to explain why the air inside the glasshouses became warmer than the air outside. [2] (ii) Use your knowledge of convection to explain why the air inside the glasshouses stayed warmer than the air outside. [2] (c) Table 5.2 shows the mass of tomatoes produced by each plant in the two glasshouses and outside. Table 5.2 mass of tomatoes produced per plant / g glasshouse A 1020 glasshouse B 2310 outside 1380 (i) Tomatoes are a fruit, produced from the fertilised flowers of tomato plants. Tomato flowers are pollinated by bees. Use the information in Fig. 5.1 to suggest why the plants produced more tomatoes in glasshouse B than in glasshouse A. [2] (ii) Suggest two factors, other than temperature, that could be different in the glasshouses compared to outside, and that could have affected the results. 1 2 [2]

14 © UCLES 2010 0653/31/M/J/10 For Examiner's Use (d) (i) Tomato fruits are red and juicy. Explain how this helps tomato seeds to be dispersed away from the parent plant. [2] (ii) Explain why it is useful to plants for their seeds to be dispersed away from the parent plant. [2]

15 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use 6 Fig.6.1 shows two dolphins communicating with each other using sound waves. Fig. 6.1 (a) Sound travels at 1500 m/s though water. It takes 0.5 seconds for the sound wave to travel from one dolphin to the other dolphin. Calculate the distance between the two dolphins. State the formula that you use and show your working. formula working [2]

16 © UCLES 2010 0653/31/M/J/10 For Examiner's Use (b) Fig. 6.2 shows the motion of a dolphin travelling through water for 30 seconds. time / s speed / m per s 2.0 1.5 1.0 0.5 0 0 20 5 25 10 30 15 Fig. 6.2 (i) On the graph, use a letter A to label a period when the dolphin was accelerating. [1] (ii) Describe the motion of the dolphin between 5 and 15 seconds. [1] (iii) Calculate the total distance travelled by the dolphin. Show your working. [2]

17 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (c) Rays of light from the Sun hit the surface of the water. Some light rays are refracted at the surface and some are reflected. The incident and refracted rays are shown on the diagram in Fig. 6.3. incident ray refracted ray air surface water Fig. 6.3 (i) On Fig. 6.3 use a ruler to draw a ray which is reflected from the surface. [1] (ii) Label clearly the angle of incidence, i, and angle of reflection, r. [1]

18 © UCLES 2010 0653/31/M/J/10 For Examiner's Use 7 The skin helps to regulate the body temperature. This is an important part of homeostasis. (a) The skin is an organ. Explain the meaning of the term organ. [1] (b) Fig. 7.1 shows the skin when the body is too cold and when it is too hot. too cold too hot sweat glands blood vessel Fig. 7.1 Explain how each of the changes shown in Fig. 7.1 helps the body to cool down when it is too hot. (i) the change in the activity of the sweat gland [2] (ii) the change in the width of the blood vessels [2]

19 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (c) Another example of homeostasis is keeping the blood sugar level constant. (i) Name the sugar that is transported in the blood. [1] (ii) Name the hormone that reduces the blood sugar level if it gets too high. [1] (iii) Suggest why it is harmful to the body if the blood sugar level falls very low. [2]

20 © UCLES 2010 0653/31/M/J/10 For Examiner's Use 8 The bar charts in Fig. 8.1 show the approximate percentages of the main gases in the atmospheres of three planets, X, Y and Z, in our solar system. carbon dioxide nitrogen oxygen other gases 100 80 60 40 20 0 % planet Y carbon dioxide nitrogen oxygen other gases 100 80 60 40 20 0 % planet Z carbon dioxide nitrogen oxygen other gases 100 80 60 40 20 0 % planet X Fig. 8.1 (a) (i) Explain briefly how the information in Fig. 8.1 shows that planet Y is not the Earth. [1] (ii) Name one of the ‘other gases’ in unpolluted air on the Earth. [1]

21 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use (b) Fig. 8.2 shows apparatus which can be used to measure the percentage of oxygen in the atmosphere of planet Z. 50 50 100 100 many small pieces of copper 100 cm3 air from planet Z piston gas syringe A B 50 50 100 100 A B Fig. 8.2 When the piston of gas syringe A is pushed in the direction of the arrow, the air flows through the pieces of copper into syringe B. The lower diagram in Fig. 8.2 shows how the apparatus appears when this is done. The pieces of copper are then heated very strongly. The air is pushed many times between A and B over the hot copper. The copper reacts with all the oxygen in the air. The apparatus is then allowed to cool to room temperature. (i) Predict the volume of gas which remains in the apparatus at the end of the experiment. Explain your answer. volume explanation [3]

22 © UCLES 2010 0653/31/M/J/10 For Examiner's Use (ii) In the experiment, many small pieces of copper, rather than a single larger piece are used. Explain, in terms of particles, the effect this has on the rate of the oxidation reaction. [3]

23 © UCLES 2010 0653/31/M/J/10 [Turn over For Examiner's Use 9 (a) Alpha, beta and gamma are three types of radiation emitted during radioactive decay. (i) State the meaning of the term radioactive decay. [1] (ii) Alpha radiation is described as ionising radiation. Explain the meaning of the term ionising radiation. [1] (b) (i) Explain why alpha radiation is deflected by an electric field but gamma radiation is not. [1] (ii) Explain why beta radiation is deflected the opposite way to alpha radiation by an electric field. [1] (iii) Explain why it is more dangerous to swallow a substance that emits alpha radiation than one that emits gamma radiation. [2] (c) We are exposed to radiation all the time and we receive it in various ways. What name is given to the radiation that is around us all the time? [1]

24 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 0653/31/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 0653/31 Paper 31 (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 31 © UCLES 2010 1 (a) community ; ecosystem ; [2] (b) all five organisms included ; arrows between them going the right away ; all links present and correct (allow one missing arrow, or heron / pike feeding on only one species / penalise any incorrect link) ; pond weed water snails water voles heron pike [3] (c) (i) no food (for primary consumers) ; no oxygen ; [2] (ii) terracing / undulations / keep plant cover / other ; [1] [Total: 8] 2 (a) (i) parallel ; [1] (ii) 1 / R = 1 / R 1 + 1 / R 2 (whole equation needed unless R1R2 ÷ R1+R2) ; 1 / R = ¼ + ¼ = ½ ; R = 2 ohms ; [3] (b) larger, turning force / moment ; because distance is larger/moment = F × d ; [2] (c) work done = force × distance ; = 250 × 10 = 2500 J ; [2] [Total: 8]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 31 © UCLES 2010 3 (a) sodium is too / very reactive / very little strength ; [1] (b) (i) Fe2O3 + 3 CO → 2Fe + 3 CO2 ; [1] (ii) two from iron oxide / carbon dioxide / oxygen / iron ions ; one relevant reference to removal of oxygen / gain of electrons ; [2] (e.g. iron (ions) because it gains (three) electrons) (c) (i) they gain electrons / are reduced / are discharged / become atoms / neutralised ; correct description of each ion gaining three electrons each ; [2] (ii) aluminium more reactive than iron ; aluminium more reactive than C or CO ; aluminium more strongly bonded to oxygen ; [max 2] (iii) +3 ; working showing the need to balance charges ; also allow discussion of how aluminium atoms gain noble gas configuration ; [max 2] [Total: 10] 4 (a) (i) Y ; [1] (ii) X – bromine Y – iodine / astatine Z – fluorine / chlorine ; [1] (b) (i) 10 ; [1] (ii) 2 × 19/38 ; [1] (ignore any units) (c) (i) × × × × × × × Cl H shared pair (showing dot and cross) ; filled chlorine shell ; [2] (if chemical symbols used they must be correct) (ii) H+ / Cl – ; [1]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 31 © UCLES 2010 (d) (i) chlorine with potassium bromide ; [1] (ii) chlorine is more reactive than bromine (reject bromide) / chlorine displaces bromine / oxidises bromide ions ; [1] (allow correct equation) [Total: 9] 5 (a) May, June ; [1] (b) (i) linking of infra-red with heat ; idea that (more) heat produced inside the glasshouse ; heat trapped inside / stays in the glasshouse ; [max 2] (ii) warm air less dense than cold ; warm air near the ground (outside) rises ; warm air cannot rise / get out of the glasshouses ; [max 2] (c) (i) too hot (in A) ; for bees (to pollinate flowers / to be active) ; for plant's, metabolic reactions / enzymes ; more water lost ; [max 2] (ii) carbon dioxide (concentration) ; wind ; water supply / humidity ; pests / animals ; weeds ; soil / availability of minerals ; (sun)light ; (reject sunshine and refs to bees) [max 2] (d) (i) attractive to animals ; eat fruit / carry fruit away ; and egest seeds in a different place ; [max 2] (ii) less competition ; for, light / space / water / minerals ; colonise new areas ; [max 2] [Total: 13]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 31 © UCLES 2010 6 (a) (distance =) speed × time ; =1500 × 0.5 = 750 m ; [2] (b) (i) A shown on any part where there is acceleration / deceleration ; [1] (ii) constant speed / uniform motion / moves at 1.5 m per s ; [1] (iii) working shown (area under graph) ; 30 m ; [2] (c) (i) straight line drawn at correct angle (angle of incidence = angle of refraction) ; [1] (ii) angle of incidence and angle of refraction ; [1] [Total: 8] 7 (a) group of tissues (performing a particular function) ; [1] (accept e.g. a muscle made of many tissues and other specific examples) (b) (i) sweat secreted (onto surface of skin) / sweat produced ; water evaporates ; using heat (from the skin) ; [max 2] (ii) capillaries / arterioles, get wider / vasodilation ; more blood flowing near surface ; more heat lost from blood (to air) ; [max 2] (c) (i) glucose ; [1] (ii) insulin ; [1] (iii) cells cannot respire ; no energy ; avp e.g. symptoms of relevant disease e.g. diabetes / damage from fainting, etc. ; [max 2] [Total: 9]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 31 © UCLES 2010 8 (a) (i) (Earth’s atmosphere) is 78–80 % N2 22-20% O2 / N2 and / or O2 too / very low / CO2 too high ; [1] (ii) water vapour / any noble gas ; [1] (b) (i) 78 – 80 cm3 ; oxygen removed by reaction (with copper) / copper oxide formed ; which has virtually no volume ; so remaining gas is nitrogen (and other gases) ; so remaining gas volume is 78-80% of 100 cm3 ; [max 3] (ii) greater surface area ; increases rate of reaction ; reference to increase of collision frequency between oxygen and copper ; [3] [Total: 8] 9 (a) (i) emission of small particles and energy from an (unstable) nucleus ; (reject breakdown of nucleus) [1] (ii) can remove electrons from atoms / can form ions ; [1] (b) (i) alpha is electrically charged and gamma has no charge ; [1] (ii) they have opposite charges / alpha is positively charged and beta is negatively charged ; [1] (iii) alpha radiation is more ionising (than gamma) ; alpha more likely to be absorbed / cannot escape ; will cause more damage internally ; [max 2] (c) background (radiation) ; [1] [Total: 7]