Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2011 May/June Paper 2 · Variant 1

This document consists of 24 printed pages. IB11 06_0654_21/4RP © UCLES 2011 [Turn over *8820570979* 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 CO-ORDINATED SCIENCES 0654/21 Paper 2 (Core) May/June 2011 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 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 2011 0654/21/M/J/11 For Examiner's Use 1 A student carried out an experiment to find which substances in the environment caused nails made of mild steel to become rusty. She selected three identical nails and placed them in sealed test-tubes, A, B and C, as shown in Fig. 1.1. dry air only A air and water vapour B nitrogen gas and water vapour C water Fig. 1.1 The student observed that only the nail in test-tube B became rusty. (a) Mild steel is an alloy. Describe briefly how the composition of mild steel is different from iron. [1] (b) (i) Explain why the nail in test-tube B in Fig. 1.1 rusted but the nails in the other two tubes did not. [3] (ii) Name the type of chemical reaction which occurs when mild steel rusts. [1]

3 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (iii) Objects made mainly of iron have been recovered from sunken ships which have lain on the sea-bed for many years. Suggest why such objects have not rusted away. [1] (c) Bicycle chains that are made of steel are usually kept covered in oil made of hydrocarbon molecules, which help to prevent rusting. steel chain (i) Explain which of the chemical formulae, V to Z, shown below, represent hydrocarbons. V H2OC W C2H2 X C6H12O6 Y C10H22 Z HCN chemical formulae explanation [2] (ii) Suggest one property of a hydrocarbon oil which makes it suitable for use as a barrier to prevent rusting. [1]

4 © UCLES 2011 0654/21/M/J/11 For Examiner's Use (d) Most bicycle tyres are made of rubber which is a natural material made of polymer molecules. Describe briefly how a polymer molecule differs from a simple molecule. You may draw a diagram to help you to answer this question. [1]

5 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use 2 (a) Fig. 2.1 shows how radar is used to detect aircraft. Radar uses microwaves with a frequency of about 10 000 MHz. Short microwave pulses are sent from the transmitter, reflected from the aircraft and received. The time it takes for the wave pulse to make the journey there and back is measured. Microwave pulses travel at 300 000 000 m / s. transmitter and receiver Fig. 2.1 (a) (i) Explain the meaning of the term frequency. [1] (ii) A radar transmitter sends a microwave pulse which is reflected from the aircraft. The microwave pulse returns to the receiver 0.000 027 s after transmission. Calculate the distance of the aircraft from the radar transmitter. State the formula that you use and show your working. formula used working m [3]

6 © UCLES 2011 0654/21/M/J/11 For Examiner's Use (b) The mass of the aircraft is 140 000 kg. Calculate the kinetic energy of the aircraft as it travels at 100 m / s. State the formula that you use and show your working. formula used working J [2] (c) Fig. 2.2 shows four forces acting on the aircraft as it flies at a constant speed and altitude. B D A C Fig. 2.2 (i) Name forces C and D. C D [1] (ii) Explain how you know that forces B and D must be equal and opposite. [1]

7 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (d) As the aircraft lands, it is travelling at 85 m / s. It moves along the runway and decelerates at a uniform rate for 40 s until it stops. Calculate the deceleration of the aircraft along the runway. State the formula that you use and show your working. formula used working m / s2 [2]

8 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 3 The smell of food cooking is detected by special cells in a person's nose. The salivary glands may respond to this stimulus by secreting saliva. (a) Name the receptor and the effector in this response. receptor effector [2] (b) When food has been taken into a person's mouth, it is mixed with saliva. Saliva contains the enzyme amylase. (i) What is an enzyme? [2] (ii) Describe the function of amylase. [2]

9 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) Fig. 3.1 shows a section through a molar tooth. enamel dentine pulp cavity Fig. 3.1 (i) Describe how the molar teeth help in the digestion of food. [2] (ii) If food is left on or between the teeth, they may start to decay. Describe how tooth decay happens. [3] (iii) Explain why a diet containing milk and other dairy foods can help to form strong teeth. [2]

10 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 4 (a) In older television sets there is a tube which contains three heated wires (filaments). The picture on the screen is produced when emissions from these wires are made to hit the screen. (i) Name the particles emitted by these hot wires. [1] (ii) State the charge on these particles. [1] (iii) The heated wire has an electrical resistance. State two factors which affect the resistance of a piece of wire. 1 2 [2] (b) The picture on the television screen is composed of many tiny dots of light. The dots of light consist of the three primary colours of light. (i) Name these three colours. 1 2 3 [2] (ii) Suggest why only three colours are needed. [1]

11 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) Fig. 4.1 shows the energy transferred each second by a television. heat 200 J sound 5 J light 95 J electrical energy 300 J Fig. 4.1 (i) Name the form of energy that is lost as waste energy by the television. [1] (ii) State the effect of the waste energy on the air around the television. [1] (iii) Calculate the energy efficiency of the television. Show your working. % [2]

12 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 5 The Earth provides raw materials which are processed into useful products. (a) Choose products from the list to complete the right hand column of Table 5.1. The first one has been done as an example. aluminium ceramics chlorine glass paper steel Table 5.1 raw material useful product iron ore steel clay rock salt sand and metal oxides wood [4] (b) Air is a mixture of elements and compounds. The gases nitrogen and oxygen can be separated from air which has been liquefied. Nitrogen dioxide, NO2, is a compound of nitrogen and oxygen. (i) State two differences between a mixture of two elements and a compound of the same elements. 1 2 [2] (ii) Nitrogen and oxygen can be separated from liquefied air because they have different boiling points. Suggest the process which is used to separate these elements from liquefied air. [1]

13 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) Nitrogen and hydrogen can be made to react together to form ammonia, NH3. At room temperature the rate of this reaction is extremely low and conditions must be chosen to increase it. Suggest two ways in which the reaction rate could be increased. 1 2 [2] (d) Ammonia is used to make salts which are used as fertilisers. State the type of substance which reacts with ammonia to make salts, and name the type of chemical reaction which occurs. type of substance type of reaction [2]

14 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 6 Fig. 6.1 shows a sperm cell. nucleus Fig. 6.1 (a) (i) State the name and number of the structures contained in the nucleus of a sperm cell. [2] (ii) On Fig. 6.1, use label lines to label and name two structures, other than the nucleus, that are found in all animal cells. [2] (iii) Describe two ways in which the shape of a sperm cell helps it to swim to an egg. 1 2 [2] (b) Name the organ in which sperm are produced. [1]

15 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) An investigation was carried out into the oxygen use of sperm while they were at rest and while they were swimming. The researchers measured the oxygen use of a group of 109 (one thousand million) sperm. The results are shown in Table 6.1. Table 6.1 oxygen use / units per 109 sperm per hour resting sperm 24 swimming sperm 83 (i) Suggest why the researchers measured the oxygen use for 109 sperm, rather than for a single sperm. [1] (ii) Explain why more oxygen is used when the sperm are swimming than when they are resting. [2]

16 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 7 (a) A house has a door bell which is operated by a switch at the door. The switch is closed when the bell push is operated. Fig. 7.1 shows the electrical circuit for this. switch bell Fig. 7.1 On Fig. 7.1, add another switch and connecting wires to enable the bell to work from another door as well. [1] (b) Fig. 7.2 shows a circuit for a two-way switch to operate a lamp. switch X switch Y Fig. 7.2 Using the circuit diagram in Fig. 7.2, complete Table 7.1. State the position of the switch and whether the lamp is off or on. Table 7.1 switch X switch Y lamp off or on up up up down down off down on [2]

17 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) Fig. 7.3 shows a hot water storage tank in the house. The water is heated by an electric immersion heater at the bottom of the tank. cold water inlet hot water outlet water tank electric immersion heater Fig. 7.3 (i) The heater is placed at the bottom of the tank and heats all the water. Explain why only some of the water would be heated if the heater is placed at the top of the tank. [2] (ii) The heater has a power output of 5 kW. How many joules of energy does the heater deliver in one second? J [1]

18 © UCLES 2011 0654/21/M/J/11 For Examiner's Use (d) Fig. 7.4 shows a circuit breaker. It is designed to switch off the current in a circuit if the current becomes too large. current current through wire electromagnet contacts pivot spring iron Fig. 7.4 Explain how the circuit breaker switches off the current if the current becomes too large. [3] (e) Fig. 7.5 shows a wind turbine outside the house, used to generate some of the electricity for the people in the house. Fig. 7.5 There are advantages and disadvantages of using wind turbines to generate electricity rather than using fossil fuels. (i) Name one example of a fossil fuel. [1]

19 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (ii) Give one advantage of generating electricity from the wind. [1] (iii) Give one disadvantage of generating electricity from the wind. [1]

20 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 8 Dung beetles live in places where large herbivores, such as elephants, buffalo or cattle, also live. The beetles collect dung produced by the herbivores and make it into a ball, which they roll away and bury. They lay eggs on the buried ball of dung, so that when their larvae hatch they can feed on the dung. The adults also feed on the dung. Fig. 8.1 shows a dung beetle rolling a ball of dung. Fig. 8.1 (a) Dung beetles are important in the carbon cycle. Use some of the words in the list to complete the sentences. carbon dioxide digestion nitrogen oxygen photosynthesis respiration roots stomata water Dung beetles digest the dung, producing sugars that are absorbed into their blood. The sugars are taken into the dung beetles' cells, where they are broken down during . This releases into the air. Plants absorb this gas through their . The gas is then combined with water to make carbohydrates by . [4] (b) Animal dung contains nitrates. Explain how nitrates can help plants to grow better. [2]

21 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) Farmers may use insecticides (pesticides that kill insects) on their land. (i) Explain why farmers use insecticides. [2] (ii) Using the information above, explain why using insecticides on land where cattle graze could reduce the amount of nitrates in the soil. [2]

22 © UCLES 2011 0654/21/M/J/11 For Examiner's Use 9 The chemical formulae for each of three compounds found in rocks are shown below. CaMg(CO3)2 dolomite KAlSi3O8 potassium feldspar SiO2 quartz (a) (i) State the total number of atoms shown combined in the formula of potassium feldspar. [1] (ii) When a flame test is carried out on one of the compounds in the list, a lilac colour is produced. Suggest with a reason which one of the compounds is being tested. compound reason [2] (iii) Two of the elements shown in the chemical formulae above are in Period 4 of the Periodic Table. State the name of one of these elements. [1] (b) Rocks on the Earth's surface are constantly being broken down into small pieces which may end up as part of the soil. (i) The Moon has no atmosphere. Suggest two reasons why rocks on the Moon do not break down in the same way as rocks on Earth. 1 2 [2] (ii) Explain briefly why the breakdown of rocks can improve the fertility of soil. [2]

23 © UCLES 2011 0654/21/M/J/11 [Turn over For Examiner's Use (c) Limestone is mainly calcium carbonate, CaCO3. When limestone is heated strongly for some time using a Bunsen flame, a chemical reaction occurs. The word equation for this reaction is calcium carbonate calcium oxide + carbon dioxide (i) State the type of chemical reaction which occurs. Explain your answer. type of reaction explanation [2] (ii) Predict whether the mass of calcium oxide which is produced in the reaction in (i) • is greater than, • or less than, • or the same as the mass of the calcium carbonate which is used. Circle your prediction. Explain your answer. [1] (iii) A student adds a little calcium oxide to some water to which has been added some full range indicator solution (Universal Indicator). State and explain the colour change which the student observes. colour change from to explanation [2]

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 2011 0654/21/M/J/11 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 2011 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. • Cambridge will not enter into discussions or correspondence in connection with these mark schemes. Cambridge is publishing the mark schemes for the May/June 2011 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 2011 0654 21 © University of Cambridge International Examinations 2011 1 (a) steel / an alloy is a mixture (of metals and other elements) / contains more than one element ; (mild steel) contains carbon (mixed with iron) ; [max 1] (b) (i) in B, air / oxygen and water are present (together) / air and water needed for rusting ; no water in A ; no air / oxygen in C ; [3] (ii) oxidation ; [1] (iii) not enough air / oxygen present / only water present ; [1] (c) (i) W and Y ; contain only hydrogen and carbon ; [2] (ii) does not mix with water / air / oxygen ; sticks to chain / steel ; [max 1] (d) polymer molecule much larger / longer / heavier ; idea that polymer is made from simple molecules / monomers linked into chain ; [max 1] [Total: 10] 2 (a) (i) number of waves per second ; [1] (ii) (distance =) speed × time ; = 300 000 000 × 0.000 027 = 8100 (m) ; so distance = 4050 (m) ; [3] (b) (KE = ) ½ mv2 ; = ½ × 140 000 × 100 × 100 = 7 × 108 (J) ; [2] (c) (i) C = weight, D = drag / friction / air resistance ; [1] (ii) constant speed / no acceleration (means balanced forces) ; [1] (d) (deceleration =) change in velocity / time ; = 85/40 or 2.125 (m / s2) ; [2] [Total: 10]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0654 21 © University of Cambridge International Examinations 2011 3 (a) (receptor) nose / cells in nose ; (effector) salivary glands ; [2] (b) (i) catalyst ; protein ; speeds up / controls / catalyses, metabolic reactions ; [max 2] (ii) to break down / digest starch to ; sugar / maltose ; that can be absorbed / that can move from gut into the blood ; [max 2] (c) (i) grinding / crushing ; increase surface area of food ; idea of easier access for enzymes ; [max 2] (ii) bacteria (on food residues) ; produce acids ; (acids) dissolve / react with, enamel ; make holes through which bacteria can reach, dentine / pulp cavity / living cells ; [max 3] (iii) contains calcium ; needed to form enamel ; [2] [Total: 13] 4 (a) (i) electrons ; [1] (ii) negative ; [1] (iii) length ; temperature ; cross sectional area / width / diameter ; material / resistivity / conductivity ; [max 2] (b) (i) red, green and blue ;; [2] (ii) other colours produced by a combination of these ; [1] (c) (i) heat / thermal ; [1] (ii) increase temperature / produce convection current ; [1] (iii) efficiency = useful energy output / energy input = 100 / 30 ; = 33(%) ; [2] [Total: 11]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0654 21 © University of Cambridge International Examinations 2011 5 (a) ceramics ; chlorine ; glass ; paper ; [4] (b) (i) compound has formula / fixed proportions of elements ; compound has different elements bonded together ; compound has different properties from constituents ; (significant) energy change when compound formed ; (or corresponding statements for mixture) [max 2] (ii) fractional distillation ; [1] (c) increase temperature ; increase pressure ; use catalyst ; [max 2] (d) acid ; neutralisation ; [2] [Total: 11] 6 (a) (i) 23 ; chromosomes ; [2] (ii) label to cell membrane ; label to cytoplasm ; [2] (iii) pointed head, reduces friction / streamlined ; tail for swimming ; [2] (b) testis/testicle ; [1] (c) (i) oxygen use by one sperm / single sperm quantities too small to measure ; [1] (ii) respiration ; oxygen combined with sugar to release energy ; more energy used when swimming ; [2 max] [Total: 10]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0654 21 © University of Cambridge International Examinations 2011 7 (a) diagram showing second switch in parallel with first ; [1] (b) switch X switch Y lamp off or on up up on up down off down up off down down on ;; [2] (c) (i) heated water rises / cold water sinks ; by convection ; hot water less dense / cold water more dense ; [max 2] (ii) 5000 (J) ; [1] (d) (large current produces) strong electromagnet ; (strong enough to) attract iron (on pivot) ; contacts break ; [3] (e) (i) coal / oil / gas / peat ; [1] (ii) no CO2 emissions / no addition to global warming / no use of fossil fuels / renewable ; [1] (iii) turbines unsightly / turbines noisy / can’t work if too windy / not enough wind / wildlife destroyed ; [1] [Total: 12]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0654 21 © University of Cambridge International Examinations 2011 8 (a) respiration ; carbon dioxide ; stomata ; photosynthesis ; [4] (b) nitrates absorbed by plant roots ; used for making proteins ; proteins used for making new cells ; [max 2] (c) (i) to kill / destroy, insects ; which eat / damage, crop / grass for grazing ; increase yields ; [max 2] (ii) kill dung beetles ; so dung not buried / nitrates in dung do not get into soil ; [2] [Total: 10] 9 (a) (i) 13 ; [1] (ii) potassium feldspar ; lilac shows potassium ; [2] (iii) calcium / potassium ; [1] (b) (i) no wind for sandblasting ; no water for freeze / thaw ; no water for chemical weathering ; no plants / animals for biological weathering ; [max 2] (ii) salts / minerals are released into the soil ; which plants need for healthy growth / maintenance ; [2] (c) (i) (thermal) decomposition ; (heating) causes a substance to break down into simpler ones / a large substance is broken down into smaller ones / calcium oxide (and carbon dioxide) is (are) simpler substances than calcium carbonate ; [2] (ii) (calcium oxide has lower mass) mass due to carbon dioxide has been lost / part of the calcium carbonate has been lost / calcium oxide is only a part of calcium carbonate ; [1] (iii) green to blue / purple ; reaction produces an alkali / alkaline solution / calcium hydroxide ; [2] [Total: 13]