Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2010 Oct/Nov Paper 2 · Variant 1

This document consists of 24 printed pages and 4 blank pages. IB10 11_0654_21/4RP © UCLES 2010 [Turn over *2507801115* For Examiner's Use 1 2 3 4 5 6 7 8 9 10 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/21 Paper 2 (Core) October/November 2010 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 2010 0654/21/O/N/10 For Examiner's Use 1 (a) State the word equation for photosynthesis. + + [2] (b) (i) Explain why plants need light for photosynthesis. [2] (ii) State two ways in which a plant leaf is adapted to obtain and use light for photosynthesis. 1 2 [2] (c) A student fixed a piece of black paper over a leaf, which was still attached to the plant. He left the plant in the sun for two days. He then removed the leaf from the plant and tested it for starch, after removing the black paper. (i) Use the letters given to list the correct sequence of the steps he took. A Add iodine solution to the leaf. B Place the leaf in boiling water. C Dip the leaf into water to soften it. D Place the leaf in hot ethanol. E Spread the leaf on a white tile. [3]

3 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (ii) Fig. 1.1 shows the leaf before and after he did the starch test. before testing after testing black paper Fig. 1.1 Complete the diagram of the leaf after testing in Fig. 1.1. Do not colour the diagram. Use labels to show which parts would look orange-brown and which parts would look blue-black. [2]

4 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 2 Fig. 2.1 shows the apparatus a student used to study the rate of reaction between some powdered metal and dilute hydrochloric acid. test-tube full of water water dilute hydrochloric acid conical flask 1.0 g powdered metal Fig. 2.1 When the student tilted the conical flask, the acid mixed with the powdered metal. If a reaction occurred, any gas which was produced collected in the test-tube, pushing the water out. The student measured the time taken for the test-tube to fill with gas. The student used the apparatus and method described above to compare the rates of reaction between dilute hydrochloric acid and three powdered metals, X, Y and Z. The results the student obtained are shown in Table 2.1. Table 2.1 metal mass of metal / g time for gas to fill the test-tube / seconds X 1.0 150 Y 1.0 45 Z 1.0 no gas was produced (a) (i) Name the gas produced when metals X and Y reacted with dilute hydrochloric acid. [1] (ii) Describe the test you would carry out to identify this gas. [1]

5 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (iii) Suggest and explain which metal, X, Y or Z, could have been copper. metal explanation [1] (iv) The student repeated the experiment with metal X but this time she used a single piece of metal weighing 1.0 g. State and explain how the rate of reaction would differ from the experiment in which 1.0 g of powdered metal was used. [2] (b) In another experiment, the student added powdered zinc to dilute sulfuric acid. When the bubbling stopped, there was still some powdered zinc left at the bottom of the solution. (i) Explain why the bubbling eventually stopped even though some zinc powder remained. [1] (ii) Name the salt which was left in the solution at the end of the reaction. [1]

6 © UCLES 2010 0654/21/O/N/10 (c) In areas where pollution is very low, rain falls through air which contains the gases nitrogen, oxygen and carbon dioxide. ` Chemical weathering may occur when rainwater flows over rocks. (i) Explain why rainwater which falls through unpolluted air has a pH which is slightly less than 7. [2] (ii) Describe one advantage to plants of the chemical weathering of rocks. [2]

7 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use 3 (a) Complete the sentences by choosing words from the list. Each word may be used once, more than once or not at all. expansion gas heat liquid longitudinal movement quickly slowly transverse vacuum wave Sound is a wave. Sound travels through a material by the of its particles. In a solid the particles are close together, so sound travels more than it does in a gas. Sound cannot travel through a because there are no particles present. [4] (b) Fig. 3.1 shows a mobile phone (cell phone). Energy is stored inside the mobile phone in a battery. mobile phone containing a battery Fig. 3.1 State the energy change that takes place when the battery is being charged. energy into energy [1] (c) Radio waves and visible light are forms of electromagnetic radiation. (i) Name one other form of electromagnetic radiation. [1] (ii) Give one use for the form of electromagnetic radiation you have named in (i). [1]

8 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 4 In jet engines, hydrocarbon molecules from the jet fuel mix with air and burn. This releases a large amount of energy and produces a mixture of waste gases. These waste gases pass out through the back of the jet engine into the atmosphere. jet engine air waste gases (a) Fig. 4.1 shows a molecule of octane, which is a typical hydrocarbon molecule in jet fuel. key carbon atom hydrogen atom octane Fig. 4.1 (i) State the chemical formula of octane. [1] (ii) Complete the word equation below for the complete combustion of octane. octane + + [2] (iii) Explain why the mixture of gases coming from the rear of the jet engine contains a large amount of nitrogen. [2] (iv) Explain why the metallic parts of the jet engine become hot when it is working. [1]

9 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (b) (i) A carbon atom has a proton (atomic) number 6 and a nucleon (mass) number 12. State the number of neutrons and electrons in this carbon atom. number of neutrons number of electrons [2] (ii) State the chemical symbol of another element which is in the same group in the Periodic Table as carbon. [1] (c) Table 4.1 shows information about some metallic materials. Table 4.1 material strength density mild steel very high very high aluminium low low duralumin (an aluminium alloy) very high low (i) Describe briefly how aluminium and an alloy of aluminium differ in composition. [1] (ii) Duralumin is used in the manufacture of aircraft. Explain why the properties of this material make it suitable for this purpose. [2]

10 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 5 (a) Complete the sentences about the human nervous system, using some of the words in the list. biceps brain detectors effectors nerves receptors Specialised cells in the human nervous system detect external stimuli. These cells are called . They convert the stimulus into electrical impulses in , which carry the impulse to the central nervous system. The central nervous system then sends impulses to parts of the body that respond to the stimulus, such as muscles or glands. These parts are called [3] (b) When we smell food, the salivary glands respond by secreting saliva. (i) Saliva contains the enzyme amylase. Describe the function of amylase. [2] (ii) Explain why it is necessary for most types of food that we eat to be digested. [2] (iii) Describe how food is moved through the alimentary canal, after we have swallowed it. [2]

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12 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 6 Fig. 6.1 shows a rock of mass 2 kg that is falling from the top of a cliff into the river below. cliff river falling rock Fig. 6.1 (a) Fig. 6.2 is the speed-time graph for the motion of the rock. 50 40 30 20 10 0 0 1 2 3 4 5 time / s speed m / s Fig. 6.2 (i) State the maximum speed of the rock. m / s [1] (ii) Use your answer to (i) to calculate the kinetic energy of the rock as it hits the water. State the formula that you use and show your working. formula used working J [2]

13 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (b) An observer on the top of the cliff measured the time between when he saw the rock hit the water and when he heard the sound of the splash. This time was 0.25 s. The speed of sound in air is 330 m / s. Calculate the height of the cliff. State the formula that you use and show your working. formula used working m [2] (c) The rock has a mass of 2000 g and a volume of 700 cm3. Calculate the density of the rock. State the formula that you use and show your working. State the units of your answer. formula used working [3] (d) The rock contains radioactive substances emitting high levels of ionising radiation. (i) State how the radioactivity could be detected. [1] (ii) Explain why it would be dangerous for a person to handle this rock without proper protection. [1]

14 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 7 The gray wolf, Canis lupus, is a predator that lives in North America. Fig. 7.1 shows a gray wolf. Fig. 7.1 (a) State one feature, visible on Fig. 7.1, which shows that the gray wolf is a mammal. [1] (b) The binomial for the gray wolf is Canis lupus. Another dog-like animal that lives in North America is the coyote, Canis latrans. What do these binomials tell us about the relationship between gray wolf and the coyote? [2]

15 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (c) In Wisconsin, Canada, the wolves’ diet consists mainly of white-tailed deer, beavers, and snowshoe hares. These all eat plants. (i) Construct a food web including all the organisms mentioned above. [3] (ii) State what the arrows in your food web represent. [1] (iii) With reference to your answers to (i) and (ii), suggest why wolves are rarer than white-tailed deer. [2]

16 © UCLES 2010 0654/21/O/N/10 For Examiner's Use (d) People used to shoot gray wolves. In 1978, a conservation programme for gray wolves began in Wisconsin and people were no longer allowed to shoot them. The main causes of death of wolves are disease, starvation and accidents such as collisions with vehicles. Fig. 7.2 shows the size of the gray wolf population in Wisconsin between 1986 and 2010. It also shows the predicted wolf population if the conservation programme is successful. 1985 1990 1995 2000 2005 2010 2015 2020 500 400 300 200 100 0 number of wolves year Fig. 7.2

17 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (i) Suggest why the population of gray wolves in Wisconsin is not expected to increase beyond about 500 individuals, even if they are no longer killed by humans. [2] (ii) Some people in Wisconsin are opposed to the wolf conservation programme. Explain why it is important to conserve species such as the gray wolf. [2]

18 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 8 Fig. 8.1 shows an electric heater being used to heat up 0.5 kg of water in a beaker. to power supply beaker of water heater Fig. 8.1 (a) What is the main process by which energy is transferred through the water? [1] (b) The specific heat capacity of the water is 4200 J / kg °C. (i) Explain what is meant by the term specific heat capacity. [1] (ii) The electrical energy supplied to the heater in 10 minutes was 70 000 J. Calculate the power supplied to the heater. State the formula that you use and show your working. formula used working W [2]

19 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (c) The electrical energy for the heater has been generated by burning a fossil fuel in a power station. (i) Name one suitable fossil fuel. [1] (ii) Describe one problem with the burning of fossil fuels to generate electricity. [1] (iii) State one alternative energy resource to fossil fuels, which could have been used to generate the electricity. [1]

20 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 9 (a) Copper metal reacts with oxygen gas to form copper oxide. State why this reaction is an example of oxidation. [1] (b) Table 9.1 shows information about two different types of copper oxide. Table 9.1 name colour chemical formula copper(II) oxide black CuO copper(I) oxide red Cu2O (i) Describe briefly the difference in chemical composition of these two types of copper oxide. [2] (ii) Copper is a transition metal. State one property, shown in Table 9.1, which is typical of transition metals. [1]

21 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use (c) Fig. 9.1 shows apparatus used in the electrolysis of copper chloride solution. power supply – + Fig. 9.1 (i) On the diagram, clearly label the anode and the electrolyte. [2] (ii) Copper chloride solution is a mixture of copper ions and chloride ions in water. State briefly one difference between a chlorine atom and a chloride ion. [1] (iii) When the electrolysis reaction in Fig. 9.1 is occurring, bubbles of gas appear at the surface of the anode. Describe a safe test and its result to confirm that this gas is chlorine. [2] (iv) Name the substance which forms at the cathode. [1]

22 © UCLES 2010 0654/21/O/N/10 For Examiner's Use 10 (a) A student investigated the relationship between the potential difference across a lamp and the current passing through it. She used the following apparatus: ammeter connecting wires lamp power supply voltmeter (i) Draw a suitable circuit diagram for this investigation. [4]

23 © UCLES 2010 0654/21/O/N/10 [Turn over For Examiner's Use The graph in Fig. 10.1 shows her results. 0 2 4 6 8 10 12 0.6 0.5 0.4 0.3 0.2 0.1 0 potential difference / V current / A × × × × × × × Fig. 10.1 (ii) What is the current when the potential difference is 6 V? A [1] (iii) Calculate the resistance of the lamp when the potential difference is 6 V. State the formula that you use and show your working. formula used working ohms [2]

24 © UCLES 2010 0654/21/O/N/10 For Examiner's Use (b) A student was given two bar magnets and a bar of soft iron. She carried out the following experiments. (i) She brought the magnets close together with opposite poles facing. N S N S State what she observed. [1] (ii) She brought the magnets close together with like poles facing. N S S N State what she observed. [1] (iii) She brought the soft iron bar towards one of the magnets. N S iron bar State what she observed. [1]

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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 2010 0654/21/O/N/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 October/November 2010 question paper for the guidance of teachers 0654 CO-ORDINATED SCIENCES 0654/21 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 October/November 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 – October/November 2010 0654 21 © UCLES 2010 1 (a) (i) + → + one mark for each side correct ;; [2] (b) (i) (provide) energy ; (light) allows carbon dioxide to combine with water ; [2] (ii) large surface area ; thin ; many chloroplasts / contains chlorophyll ; other valid point ; [max 2] (c) (i) B, D, C, E, A ;;; (all five correct for 3 marks, any four in correct sequence 2 marks, any three in correct sequence 1 mark) [3] (ii) area covered by paper shown on diagram ; orange-brown where paper was, blue-black elsewhere ; [2] [Total: 11] 2 (a) (i) hydrogen ; [1] (ii) lighted splint pops ; [1] (iii) (Z) copper does not react with dilute (hydrochloric) acid / is unreactive ; [1] (iv) reaction would be slower / lower collision frequency ; (single piece) has lower surface area ; [2] (b) (i) the acid had all reacted / been used up ; [1] (ii) zinc sulfate ; [1] (c) (i) carbon dioxide dissolves (and reacts) ; carbon dioxide is a non-metal oxide ; causes rain to become (slightly) acidic ; [max 2] (ii) minerals / compounds dissolve (from the rock) ; provide nutrients / essential minerals / substances needed for (healthy) growth ; [2] [Total: 11] carbon dioxide water glucose / starch / carbohydrate / sugar oxygen

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 21 © UCLES 2010 3 (a) longitudinal ; movement ; quickly ; vacuum ; [4] (b) electrical energy into chemical energy ; [1] (c) (i) microwaves, infra-red, ultraviolet, X-rays, gamma ; [1] (ii) correct use ; [1] [Total: 7] 4 (a) (i) C8H18 ; [1] (ii) + + (octane) oxygen water carbon dioxide RHS ; LHS ; [2] (iii) nitrogen is in the air / enters with the air / owtte ; nitrogen does not burn / react / change / is unreactive ; [2] (iv) heat comes from the burning fuel / combustion of the fuel is exothermic / there is an exothermic reaction (inside engine) / heat is conducted from where the fuel is burning ; [1] (b) (i) 6 ; 6 ; [2] (ii) Si / Ge / Sn / Pb ; [1] (c) (i) alloy contains more than one element / is a mixture / other correct ; [1] (ii) high strength for safety / resist breakage / because high forces on airframe in flight ; low density to reduce weight / reduce fuel cost ; [2] [Total: 12]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 21 © UCLES 2010 5 (a) receptors ; nerves ; effectors ; [3] (b) (i) changes starch ; to maltose / sugar ; [2] (ii) produces small molecules (from large ones) ; so that the (small) molecules / particles / nutrients can be absorbed ; into blood / through gut wall ; so they can be used by cells / builds new cells ; [max 2] (iii) peristalsis ; ref. to muscle contraction / circular and longitudinal muscles ; [2] [Total: 9] 6 (a) (i) 40 (m / s) ; [1] (ii) KE = ½ mv2 ; = ½ × 2 × 1600 = 1600 (J) ; (ecf) [2] (b) distance = speed × time ; 330 × 0.25 seconds = 82.5 (m); [2] (c) density = mass / volume ; = 2000 / 700 = 2.86 ; g / cm3 ; (or 2860 kg / m3) [3] (d) (i) Geiger counter / Geiger-Müller tube / any other suitable ; [1] (ii) causes ionisation within cells ; mutation ; cancer ; radiation burns / burns skin ; damages / kills cells / damages DNA ; radiation sickness ; [max 1] [Total: 10]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 21 © UCLES 2010 7 (a) fur ; [1] (b) they belong to the same genus ; but different species ; they are closely related ; they cannot breed together ; [max 2] (c) (i) white-tailed deer plants beavers gray wolf snowshoe hares all organisms at correct levels (allow if upside down) ; all organisms correctly connected ; all arrows shown in correct directions ; [3] (ii) energy (flow / transfer) ; [1] (iii) energy lost along food chains ; only 10 % of energy passed on ; less energy available for, higher trophic levels / for wolves ; [max 2] (d) (i) ref. to limiting factors ; not enough food ; more disease ; competition ; [max 2] (ii) maintain biodiversity ; any ethical or moral reason ; idea that loss of one species affects others in ecosystem ; prevent wolves becoming extinct ; [max 2] [Total: 13]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 21 © UCLES 2010 8 (a) convection ; [1] (b) (i) amount of energy needed to heat up one kilogram of (water / a material) by one degree (Celsius) ; [1] (ii) (power =) energy / time ; = 70000 / 600 = 117 (W) ; [2] (c) (i) coal / oil / gas ; [1] (ii) running out / carbon dioxide emissions / sulfur dioxide ; [1] (iii) solar / wind / tides / hydroelectric power / waves etc. ; [max 1] [Total: 7] 9 (a) (definition) e.g. oxidation refers to reaction with / bonded with oxygen ; (context) e.g. oxygen has reacted / bonded with copper / copper gains oxygen ; [max 1] (b) (i) CuO shows there is one copper atom for every oxygen atom ; Cu2O shows there are two copper atoms for every oxygen atom ; there are twice as many copper atoms for every oxygen atom in Cu2O ; [max 2] (ii) coloured compounds / variable valency / ionic charge / oxidation state ; [1] (c) (i) anode and electrolyte clearly labelled ; [2] (ii) atom uncharged, ion charged ; ion has filled outer shell, atom outer shell not complete ; atom proton number equal to electron number – unequal in ion ; [max 1] (iii) damp litmus / indicator paper ; is bleached ; [2] (iv) copper ; [1] [Total: 10]

Page 7 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 21 © UCLES 2010 10 (a) (i) correct symbols for lamp, voltmeter, ammeter, power supply ; voltmeter in parallel ; ammeter in series ; everything else correct ; [4] (ii) 0.47 (A) ; [1] (iii) (resistance =) voltage / current ; = 6 / 0.47 = 12.8 (Ω); [2] (b) (i) magnets attract ; [1] (ii) magnets repel ; [1] (iii) iron bar attracted to magnet ; [1] [Total: 10]