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

This document consists of 30 printed pages and 2 blank pages. IB13 06_0654_33/4RP © UCLES 2013 [Turn over *8364803695* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/33 Paper 3 (Extended) May/June 2013 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. Electronic calculators may be used. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 32. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

2 © UCLES 2013 0654/33/M/J/13 For Examiner's Use 1 Fig. 1.1 shows an experimental car powered by solar panels. Fig. 1.1 (a) The speed / time graph in Fig. 1.2 shows the motion of the car over a short time. 0 10 20 30 time / s speed / m per s 40 50 60 10 8 6 4 2 0 Fig. 1.2 (i) On Fig. 1.2, label A at a point when the car was accelerating. [1] (ii) Calculate the total distance travelled by the car. Show your working. [2]

3 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (b) The energy output from the solar panels was measured during one day. Fig. 1.3 is a graph of the results. midnight 2am 4am 6am 8am 10am noon time of day 2pm 4pm 6pm 8pm 10pm midnight 3.0 2.5 2.0 1.5 1.0 0.5 0 energy output in kJ / s Fig. 1.3 (i) Explain why the energy output from the solar panels varies during the day. [1] (ii) The motor in the car needs 2000 J / s to move the car at 7 m / s. Use Fig. 1.3 to calculate the number of hours in the day for which the solar cells generate sufficient electricity to run the car at this speed. hours [1] (iii) The solar cells are 20% efficient. Calculate the solar energy input required to produce 2000 J / s. State the formula that you use and show your working. formula working [2]

4 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (iv) The mass of the car is 750 kg. Calculate the kinetic energy of the car when it is travelling at 7 m / s. State the formula that you use and show your working. formula working [2] (c) Fig. 1.4 shows a small photovoltaic cell (solar cell) being investigated. A resistor photovoltaic cell lamp Fig. 1.4 (i) A voltmeter is added to the circuit to measure the voltage across the photovoltaic cell. Using the correct symbol, draw the voltmeter in the correct position on Fig. 1.4. [1] (ii) The voltmeter reading is 2.5 V when the ammeter reading is 0.2 A. Calculate the power output of the photovoltaic cell. State the formula that you use and show your working. formula working [2]

5 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use 2 Petroleum (crude oil) contains hydrocarbon molecules that have a very wide range of relative formula masses. Gasoline obtained from petroleum is in great demand for car fuel. Petroleum as it exists in the Earth’s crust does not contain enough gasoline to meet this demand. The yield of gasoline from petroleum can be increased by the process of catalytic cracking. Fig. 2.1 shows a simplified diagram of catalytic cracking. solid catalyst in the form of a fine powder mixture of smaller hydrocarbon molecules mixture of large saturated hydrocarbon molecules Fig. 2.1 (a) Catalytic cracking produces a mixture of hydrocarbons that contains a higher proportion of gasoline. Suggest the full name of a process that could be used to separate this gasoline from the other hydrocarbons in the mixture. [1] (b) (i) Decane, C10H22, may be cracked in apparatus like that shown in Fig. 2.1. A symbolic equation for the cracking of decane is C10H22 one molecule of X + C2H4 Deduce the formula of a molecule of compound X. Explain your answer briefly. formula of molecule X explanation [2]

6 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (ii) Complete a bonding diagram for ethene to show • the chemical symbols of each atom, • how the bonding electrons are arranged in each atom. [2] (c) In a combustion experiment, a chemist reacts ethene with excess oxygen. The balanced symbolic equation for the combustion reaction is C2H4 + 3O2 2CO2 + 2H2O The chemist finds that 480 cm3 of carbon dioxide, measured at room temperature, have been produced. (i) Calculate the number of moles of carbon dioxide that were produced. The volume of one mole of carbon dioxide at room temperature has a volume of 24 dm3. Show your working. [2]

7 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (ii) Calculate the mass of ethene that the chemist used in his experiment. Show your working. [3]

8 © UCLES 2013 0654/33/M/J/13 For Examiner's Use 3 (a) Fig. 3.1 shows a food chain in a forest. The numbers show the energy in three trophic levels in an area of 1 m2 of forest. producers 10 000 kJ herbivores 1000 kJ carnivores 100 kJ Fig. 3.1 (i) State the form in which energy is transferred from the producers to the herbivores. [1] (ii) Calculate the percentage of the energy in the producers that is transferred to the carnivores. % [1] (iii) Describe two ways in which energy is lost from the food chain. 1 2 [2] (b) Explain how deforestation can contribute to global warming. [3]

9 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use 4 A student added excess magnesium ribbon to dilute hydrochloric acid as shown in Fig. 4.1. excess magnesium ribbon dilute hydrochloric acid thermometer Fig. 4.1 The student observed that a gas was given off and that the temperature of the mixture increased. (a) (i) Write the balanced symbolic chemical equation for the reaction between magnesium and dilute hydrochloric acid. [3] (ii) Explain why the increase in temperature of the mixture is evidence that a chemical change may have occurred. [2]

10 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (b) The student then set up the apparatus shown in Fig. 4.2. She investigated the effect of changing temperature on the rate of reaction between magnesium ribbon and dilute hydrochloric acid. gas syringe barrel of the syringe slides out as gas enters thermometer water bath to control the temperature of the mixture excess dilute hydrochloric acid magnesium ribbon Fig. 4.2 In each experiment, the student timed how long it took for 25.0 cm3 of gas to collect in the gas syringe. Some of her measurements are shown in Table 4.1. Table 4.1 temperature / °C mass of magnesium / g acid concentration / mol per dm3 time to collect 25.0 cm3 gas / s 10 0.5 1.0 83 22 0.5 1.0 38 32 0.5 1.0 19 40 0.5 1.0 10 (i) Calculate the average rate at which gas was produced at 40 °C. Show your working. cm3 / s [1]

11 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (ii) State and explain, in terms of the motion of particles, the effect of changing temperature on rate of reaction. [3]

12 © UCLES 2013 0654/33/M/J/13 For Examiner's Use 5 (a) Visible light and γ-(gamma) radiation are two regions of the electromagnetic spectrum. (i) State the speed, in km / s, of all electromagnetic waves when travelling through a vacuum. km / s [1] (ii) Name a region of the electromagnetic spectrum that is used in remote control devices for televisions. [1] (iii) State one way in which the waves in different regions of the electromagnetic spectrum differ from each other. [1] (b) Three of the following statements are true. Tick the correct statements. Both α-(alpha) radiation and β-(beta) radiation pass easily through the body. α-radiation damages cells in a very localised area of the body. Ionisation does not always kill cells – sometimes it causes them to mutate. Cancer occurs when a large number of cells are killed. The dose of radiation received depends on the length of exposure. [2]

13 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (c) Fig. 5.1 shows how the activity of a radioactive isotope varies with time. 70 60 50 40 30 20 10 0 activity / mega becquerels 0 1 2 3 time / hours 4 5 6 Fig. 5.1 Use Fig. 5.1 to estimate the half-life of this radioactive isotope. Give your answer in minutes. Show your working. minutes [2]

14 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (d) Table 5.1 shows the half-life and type of radiation given out by four different radioactive isotopes. Table 5.1 radioactive isotope half-life / days radiation given out bismuth-210 5.0 β polonium-210 138.0 α and γ radon-222 3.8 α iodine-131 8.0 β and γ (i) A sample of each isotope has the same count rate on day 1. Which sample will have the highest count rate on day 30? Explain your answer. isotope because [1] (ii) Which isotopes in Table 5.1 give out radiation which is the most ionising? Explain your answer. isotopes and because [1] (e) A radioactive source has a half-life of 6 hours. For which of the following uses might this source be suitable? Explain your answer. A to monitor the thickness of paper as it is made in a factory. B to inject into a person as a medical tracer. C to make a smoke alarm work. use(s) explanation [3]

15 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use 6 Fig. 6.1 shows a fetus and the placenta, through which it obtains oxygen and nutrients from the mother's blood. fetus maternal blood lining of uterus maternal vein D maternal artery A placenta umbilical vein B capillary network in placenta umbilical artery C Fig. 6.1 (a) Using your knowledge of arteries and veins, draw arrows on Fig. 6.1 to show the direction of blood flow in vessels A, B, C and D. [2] (b) Inside the placenta, the mother’s blood is brought close to the fetus’s blood. This allows substances to move between the mother and the fetus. (i) Name one substance that passes from the fetus's blood to the mother's blood. [1] (ii) Name two useful substances, other than oxygen, that pass from the mother’s blood to the fetus’s blood. 1 2 [2]

16 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (c) Oxygen passes from the mother’s blood to the fetus’s blood in the placenta. (i) Describe how oxygen is carried in the mother’s blood. [2] (ii) In an adult, oxygen enters the blood from the alveoli in the lungs. Table 6.1 shows information about the gas exchange surface in the lungs and in the placenta. (1 µm = 0.001 mm) Table 6.1 feature lungs placenta distance across the surface / µm 0.5 3.5 total surface area / m2 55 16 rate of blood flow / cm3 per minute 5000 600 (mother’s side) 300 (fetus’s side) Explain why more oxygen can be absorbed per minute across the lungs than across the placenta. Use your knowledge of gas exchange surfaces, and the information in Table 6.1, in your answer. [4]

17 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use 7 (a) Explain briefly why copper is sometimes found uncombined in the Earth’s crust but metals like sodium and magnesium are never found uncombined. [2] (b) Fig. 7.1 shows a simple diagram of the structure of bronze. tin atom copper atom Fig. 7.1 (i) State the general name of materials such as bronze. [1] (ii) Predict and explain briefly whether bronze would be a harder or a softer material than copper. prediction [2] (iii) Suggest, with a reason, whether bronze should be described as a mixture or as a compound. [1]

18 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (c) Fig. 7.2 shows two electrolysis processes (cells) connected in series with a d.c. electrical power supply. bubbles of gas d.c. power supply copper sulfate solution S T U V Fig. 7.2 Electrode S is a steel spoon which is being electroplated with a thin layer of metallic copper. Electrodes U and V are made of carbon in the form of graphite. The electrolyte in both processes is aqueous copper sulfate, which contains copper ions, Cu2+ and sulfate ions, SO4 2-. (i) Describe and explain, in terms of ions, electrons and atoms, what happens to cause a layer of copper atoms to build up on the surface of electrode S. [4] (ii) Name a gas that is contained in the bubbles rising from the surface of electrode V. [1]

19 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (iii) Electrode T is made of a piece of copper which shows no visible change during the time that electrode S is being electroplated. A student knows, however, that electrode T slowly dissolves. Suggest how the student could obtain experimental evidence that some of the copper in electrode T had dissolved. [2]

20 © UCLES 2013 0654/33/M/J/13 For Examiner's Use 8 Fig. 8.1 shows a washing machine. When the door is closed and the machine is switched on, an electric motor rotates the drum and clothes. drum door Fig. 8.1 (a) The instruction booklet for the washing machine contains this information. wash cycle average power during wash cycle / kW time taken to run cycle / minutes fast 1.1 40 cool 1.2 90 hot 1.5 110 (i) Use the information to calculate the energy transferred in joules to the washing machine during the fast wash cycle. State the formula that you use and show your working. formula working J [3]

21 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (ii) Explain why reducing the amount of energy used by washing machines could reduce the amount of carbon dioxide emitted into the atmosphere. [2] (b) (i) A current of 3 A passes through the heating element when the voltage across it is 220 V. Calculate the resistance of the heating element. State the formula that you use and show your working. formula working [2] (ii) The heating element uses this current for 12 minutes. Calculate the electric charge which passes through the heating element in this time. State the formula that you use and show your working. formula working [2]

22 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (c) Inside the washing machine, some of the water evaporates when the washing machine is being used. (i) During evaporation, water changes state from liquid to gas. Complete the diagrams to show the arrangement of particles in a liquid and in a gas. liquid gas [3] (ii) Explain, in terms of particles, the process of evaporation. [3]

23 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use 9 Fig. 9.1 shows a pitcher plant, which grows in Malaysia and Indonesia. green leaf slippery rim of pitcher pitcher (shown in section) spines solution containing partly-digested insects Fig. 9.1 (a) The leaves of pitcher plants carry out photosynthesis, using carbon dioxide and water to make carbohydrates. They obtain carbon dioxide and water in the same way as other plants. (i) Describe how the leaves obtain carbon dioxide. [3] (ii) Describe how the leaves obtain water. [3]

24 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (b) Pitcher plants grow where the concentration of nitrate ions in the soil is very low. Most plants need nitrate ions to make amino acids and proteins. Pitcher plants use a different way of obtaining amino acids. They trap insects in their pitchers, and produce a solution that digests the proteins in the insects' bodies. (i) Define the term digestion. [2] (ii) Suggest what is present in the solution that the pitcher plant produces inside its pitchers, to enable digestion to take place. [2] (c) A scientist investigated why insects visit the pitchers. She took several identical Petri dishes. • She placed a piece of the rim of a pitcher, or a small amount of solution from inside the pitcher or water, on one side of the dish. • She put a small amount of water on the other side, as shown in Fig. 9.2. • She then placed either an ant or a fruit fly in the centre of the dish. She recorded which side of the dish the insect moved to. She repeated this 19 more times with each type of insect, using a different insect each time. Petri dish water piece of rim or solution from pitcher or water Fig. 9.2

25 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use Table 9.1 shows her results. Table 9.1 number of insects that moved to each side substance on left side of dish substance on right side of dish insects left right ants 16 4 piece of rim water fruit flies 14 6 ants 4 16 solution from pitcher water fruit flies 8 12 ants 10 10 water water fruit flies 9 11 (i) Suggest why the scientist placed water on both sides of some dishes. [1] (ii) Use information in Table 9.1 to describe how the responses of the insects to a stimulus help them to avoid being caught in the pitchers. [1] (iii) Pitcher plants have several features that help them to catch insects in their pitchers. Use information in Fig. 9.1 and Table 9.1 to explain how they do this. [3]

26 © UCLES 2013 0654/33/M/J/13 For Examiner's Use 10 (a) When wood is burnt, a solid material known as wood ash remains. Wood ash contains calcium carbonate and potassium compounds which can be used to improve the quality of soil. (i) Explain briefly how calcium carbonate and potassium compounds could improve the quality of soil. calcium carbonate potassium compounds [3] (ii) The chemical formula of potassium carbonate is K2CO3. Potassium is in Group 1 of the Periodic Table. Predict and explain the formula and charge of the carbonate ion. Show your working. [2]

27 © UCLES 2013 0654/33/M/J/13 [Turn over For Examiner's Use (b) Soil quality is also improved by the addition of nitrogen compounds such as ammonium nitrate. Nitrogen compounds are made industrially using ammonia, NH3, which is produced from nitrogen and hydrogen in the Haber process. Fig. 10.1 shows a simplified flow diagram of part of the Haber process. nitrogen ammonia hydrogen catalyst reaction vessel Fig. 10.1 (i) Name the main substance in the catalyst shown in Fig. 10.1. [1] (ii) Explain briefly why a catalyst is required in the reaction vessel. [1] (iii) Name the substance that neutralises ammonia to produce ammonium nitrate. [1]

28 © UCLES 2013 0654/33/M/J/13 For Examiner's Use 11 (a) Complete the graph in Fig. 11.1 to show how enzyme activity is affected by temperature. You should include a scale on the ‘temperature’ axis. rate of enzyme activity temperature / °C 0 Fig. 11.1 [3] (b) The internal body temperature of a human is kept constant, allowing enzymes to work efficiently. Fig. 11.2 outlines how receptors and effectors are involved in this process. receptors detect a change in temperature effectors act to return temperature to normal Fig. 11.2 (i) State one place in the body where receptors detect a change in body temperature. [1] (ii) Explain how the muscles can help to return a low body temperature to normal. [2]

29 © UCLES 2013 0654/33/M/J/13 For Examiner's Use (iii) This control mechanism involves negative feedback. Explain what is meant by the term negative feedback. [2]

30 © UCLES 2013 0654/33/M/J/13 BLANK PAGE

31 © UCLES 2013 0654/33/M/J/13 BLANK PAGE

32 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2013 0654/33/M/J/13 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2013 series 0654 CO-ORDINATED SCIENCES 0654/33 Paper 3 (Extended Theory), maximum raw mark 120 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the May/June 2013 series for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level components.

Page 2 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 33 © Cambridge International Examinations 2013 1 (a) (i) A labelled between 0 s and 20 s ; [1] (ii) working on graph / calculation of area under graph ; 280 m ; [2] (b) (i) energy input (to panel) from sun / energy from sun (to panel), varies ; [1] (ii) 6 hours (as graph worked) ; [1] (iii) efficiency = (useful) (energy) output / (energy) input ; energy input = 2000/0.2 = 10000 J / s ; [2] (iv) (kinetic energy =) ½ mv2 ; = ½ × 750 × 7 × 7 = 18 375 J ; [2] (c) (i) voltmeter in parallel with photocell and correct symbol ; [1] (ii) power = voltage × current ; = 2.5 × 0.2 = 0.5 W ; [2] [Total: 12] 2 (a) fractional distillation ; [1] (b) (i) C8H18 ; total number of each type of atom must be same on both sides of equation ; [2] (ii) double bond shown ; single bonds shown ; C C H H H H x x x x x x x x [2] (max 1 mark if symbols missing or incorrect) (c) (i) 480 ÷ 24 000 ; = 0.02 ; [2]

Page 3 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 33 © Cambridge International Examinations 2013 (ii) number of moles of ethene used = 0.02 ÷ 2 = 0.01 ; Mr ethene = (12 × 2) + (1 × 4) = 28 ; mass of 0.01 moles ethene = 28 × 0.01 = 0.28 g ; [3] [Total: 10] 3 (a) (i) chemical (energy) ; (accept: potential) [1] (ii) 1 (%) ; [1] (iii) respiration ; as heat ; movement / kinetic ; not all organisms eaten / not all parts of organisms eaten ; not all food digested / some lost in faeces ; [max 2] (b) less photosynthesis (as fewer trees) ; so less carbon dioxide removed / used ; trees burned ; producing carbon dioxide ; more carbon dioxide in atmosphere contributes to greenhouse effect / traps heat ; [max 3] [Total: 7] 4 (a) (i) Mg + 2HCl → MgCl2 + H2 ;;; [3] (LHS ; RHS ; and balanced ;) (ii) heat energy has been transferred / released into the mixture ; (heat released by) exothermic reaction ; chemical energy transferred into heat energy ; products have lower chemical energy content than reactants ; [max 2] (b) (i) 2.5 ; [1] (ii) the higher the temperature the higher the rate ; if temperature increases then speed / KE of molecules increases ; reactions occur when molecules collide ; if speed increases collision frequency increases ; and collision energy increases ; which leads to greater chance of reaction ; [max 3] [Total: 9] 5 (a) (i) 3 × 105 (km/s) ; [1] (ii) infra-red ; [1] (iii) wavelength / frequency ; [1]

Page 4 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 33 © Cambridge International Examinations 2013 (b) both alpha radiation and beta radiation pass easily through the body
alpha radiation damages cells in a very localised part of the body  ionisation does not always kill cells – sometimes it causes them to mutate  cancer occurs when a large number of cells are killed
the dose of radiation received depends on the length of exposure  (all five boxes correct = 2 marks, four boxes correct = 1 mark) ;; [2] (c) half-life = 90 (minutes) ; working ; [2] (d) (i) polonium –210 (no mark) largest / longest half-life ; [1] (ii) polonium and radon, (no mark) alpha is most ionising / both emit alpha ; [1] (e) use(s) B to inject into a person as a medical tracer ; explanation A and C need long half-lives to work ; B needs short half-life so that it does not remain in body / owtte ; but long enough so that it can be monitored ; [max 3] [Total: 12] 6 (a) arrow on A pointing downwards arrow on B pointing downwards arrow on C pointing upwards arrow on D pointing upwards (all four correct for two marks, two or three correct for one mark) ;; [2] (b) (i) urea / carbon dioxide ; [1] (ii) water ; one from – amino acid / glucose / fatty acid / glycerol / named relevant element / named vitamin ; antibodies ; [max 2] (c) (i) by red blood cells ; by haemoglobin ; combined with haemoglobin / as oxyhaemoglobin ; [max 2]

Page 5 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 33 © Cambridge International Examinations 2013 (ii) reference to diffusion ; shorter distance to travel (therefore less time taken (for diffusion)) ; more surface area (therefore more can move across at once) ; greater, rate of more, blood flow (so oxygen taken away faster) ; idea that this maintains diffusion gradient ; comparative use of figures, e.g. distance across surface in lungs is 7 times smaller than in placenta ; [max 4] [Total: 11] 7 (a) copper unreactive / stable enough to exist as metal ; sodium and magnesium react easily with, non-metals e.g. oxygen ; [2] (i.e. 1 general reactivity mark and 1 mark for relevant extra detail) (b) (i) alloy ; [1] (ii) harder tin atoms disrupt layers of copper atoms ; making it more difficult for layers to move over each other / which means more energy required to make layers slip ; [2] (iii) mixture proportions of tin and copper can vary / no fixed chemical formula ; OR compound atoms of different elements are bonded ; some properties of bronze are different from either tin or copper ; [max 1] (c) (i) spoon / electrode S is a cathode / negatively charged ; so attracts positive copper ions ; copper ions gain electrons ; copper ions gain two electrons / are discharged / converted into copper atoms ; copper atoms bond together / stick to steel spoon ; [max 4] (ii) oxygen / carbon dioxide / carbon monoxide ; [1] (iv) weigh the electrode before and after the process ; decrease in mass provides the required evidence ; OR use micrometer to find / measure electrode thickness before and after the process ; decrease in thickness provides the required evidence; [max 2] [Total: 13]

Page 6 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 33 © Cambridge International Examinations 2013 8 (a) (i) (energy =) power × time ; 1100 × 40 × 60 ; = 2 640 000 (J) ; [3] (ii) electricity could be produced by burning fossil fuels / named example ; (fossil) fuels when burned / power stations release CO2 ; reduced demand for (fossil) fuels / electricity reduces amount of CO2 released ; [max 3] (b) (i) (R =) V/I ; R = 220 / 3 = 73 Ω ; [2] (ii) charge = current × time ; = 3 × 12 × 60 = 2160 C ; [2] (c) (i) liquid particles touching and similar size ; gas particles not touching ; random arrangement for both ; [3] (ii) faster moving molecules ; can do more work against attractive forces / can break bonds between them / owtte ; break free / separate turn into gas / leave liquid ; energy / heat (from surroundings) used for this ; [max 3] [Total: 15] 9 (a) (i) from the air ; by diffusion ; through stomata ; [3] (ii) from the soil ; absorbed by root hairs ; by osmosis (into roots / xylem) ; up xylem to leaves ; pulled up by transpiration ; [max 3] (b) (i) breakdown of large molecules; so that they can be absorbed / become soluble ; [2] (ii) enzymes ; proteases ; trypsin / pepsin ; [max 2]

Page 7 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 33 © Cambridge International Examinations 2013 (c) (i) as a control / to make sure the only variable was the substance used ; [1] (ii) they moved away from the side containing the solution from the pitcher ; [1] (iii) pitchers have slippery rim (so insects fall in) ; pitchers have downward-pointing spines (so insects can't crawl out) ; rim attracts insects ; avp ; [max 3] [Total: 15] 10 (a) (i) max 2 from either part: reduce acidity / increase pH / neutralise acids ; calcium carbonate reacts with / neutralises acids ; releases nutrients from soil ; increase plant nutrient levels / fertilises ; potassium compounds are essential for healthy plant growth / increases yield ; neutralises acids (if not credited above) ; [max 3] (ii) potassium ion is K+ / charges must balance ; so carbonate is CO3 2– ; [2] (b) (i) iron ; [1] (ii) nitrogen and hydrogen too unreactive / react too slowly (without it) ; catalyst speeds up the reaction / allows the reaction to occur ; [max 1] (iii) nitric acid ; [1] [Total: 8] 11 (a) curve goes up and then down again ; peak between 30 and 45 °C ; rate zero (by 60 °C or sensible figure) ; OR up and down (including two straight lines) ; sensible scale shown ; correct shape ending at zero ; [max 3] (b) (i) skin / brain / hypothalamus ; [1] (ii) contract / shiver ; release heat ; [2] (iii) sensor / receptor detects a change from normal / example / owtte ; brings about a response that returns factor towards normal / example ; [2] [Total: 8]