Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2013 May/June Paper 2 · Variant 2

This document consists of 27 printed pages and 1 blank page. IB13 06_0654_22/4RP © UCLES 2013 [Turn over *6597812837* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/22 Paper 2 (Core) 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 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.

2 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 1 (a) Fig. 1.1 shows some of the elements in Group 1 of the Periodic Table. Na K Li Fig. 1.1 (i) Name the alkali that is produced when potassium reacts with water. [1] (ii) Describe how the rate of reaction between water and the metals in Fig. 1.1 changes as you go down the group. [1] (b) Fig. 1.2 shows some of the elements in Group 7 of the Periodic Table. Br I Cl Fig. 1.2 (i) Describe how the melting point of the elements in Fig. 1.2 changes as you go down the group. [1] (ii) A solution of potassium bromide is colourless and a solution of chlorine is almost colourless. Describe and explain briefly what would be seen when these solutions are mixed. what would be seen explanation [3]

3 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use 2 (a) An elephant of mass 5000 kg exerts a constant force to push a tree trunk along at a steady speed of 1.5 m / s. State the two quantities that would need to be measured to calculate the work done by the elephant. and [2] (b) The volume of the elephant is 5 m3. Its mass is 5000 kg. Calculate the density of the elephant. State the formula that you use and show your working. formula working kg / m3 [2] (c) An elephant can communicate with other elephants using infrasound. This is a very low frequency vibration which it is usually impossible for a human to hear. (i) Suggest a possible frequency for this vibration and explain why you chose your answer. frequency Hz explanation [2] (ii) State the meaning of the term frequency. [1]

4 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 3 Fig. 3.1 shows an animal cell, just before it divides. cell membrane cytoplasm chromosome Fig. 3.1 (a) Define the term chromosome. [2] (b) Some cattle have horns, but other cattle do not. This is determined by a gene. The allele of the gene that produces horns, h, is recessive. (i) Complete Table 3.1 to show the phenotypes of cattle with each of the possible genotypes for this gene. Table 3.1 genotype phenotype HH no horns Hh hh [1]

5 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (ii) A farmer has a bull with no horns. He wants to make sure that the bull does not have the recessive allele, h, for horns. He breeds the bull with a cow that has horns. Complete the genetic diagram to show the possible offspring if the bull does have the allele for horns. parents genotype of parents gametes bull with no horns Hh and cow with horns hh gametes from cow gametes from bull [3] (iii) Explain how the results of the cross can help the farmer to decide whether the bull has the allele h or not. [2] (iv) Cows usually give birth to one or two calves each time. Explain why the farmer needs to cross the bull with the cow several times before he can be sure whether the bull has the allele h or not. [2]

6 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 4 Fig. 4.1 shows a microwave oven. Fig. 4.1 (a) Microwaves cook food by transferring energy to the food. Choose words from the list to complete the sentences below. You may use each word once, more than once or not at all. chemical conduction convection potential radiation thermal Microwaves are absorbed by the outer layers of food. The microwave energy is transferred to water and fat molecules in these layers, increasing the energy of these layers. energy is mostly transferred to the centre of solid food by . [2]

7 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (b) A student heated some water in a microwave oven for five minutes. Fig. 4.2 shows how the temperature of the water changed. 100 50 0 0 1 2 time / minutes temperature / °C 3 4 5 Fig. 4.2 The temperature of the water stops increasing after two minutes. Explain what happened to the water molecules during the five minutes. [3] (c) The microwave oven is made of solids. The water is a liquid. Complete Fig. 4.3 to show the arrangement of particles in a liquid. The diagram for a solid has been done for you. solid liquid Fig. 4.3 [2]

8 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 5 (a) Sodium is a reactive metal that forms compounds with non-metals. (i) Name the compounds which are formed when sodium reacts with chlorine, oxygen. [1] (ii) Fig. 5.1 shows diagrams of a sodium atom and a chlorine atom. Na Cl Fig. 5.1 When sodium reacts with chlorine, the atoms shown in Fig. 5.1 first change into electrically charged atoms known as ions. Describe what happens when sodium and chlorine atoms change into ions. [2] (iii) State why the ions formed by sodium and chlorine attract each other. [1] (iv) Describe two differences between the properties of a typical ionic compound and a typical covalent compound. 1 2 [2]

9 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (b) Fig. 5.2 shows apparatus a student used to investigate the electrolysis of dilute sulfuric acid. d.c. power supply + – dilute sulfuric acid Q P Fig. 5.2 (i) On Fig. 5.2, label the anode. [1] (ii) Name the gases P and Q. P Q [2] (iii) Choose one of the gases in (ii) and describe a test for this gas. gas description of test [2]

10 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 6 Fig. 6.1 shows a section through a blood capillary. cell A cell B Fig. 6.1 (a) Describe how cell A transports oxygen. [2] (b) Describe the function of cell B. [2] (c) Outline the functions of a blood capillary. [2]

11 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use 7 (a) A resistor of 1200 Ω is connected in series with another resistor of 2400 Ω. Calculate the combined resistance of these two resistors. State the formula that you use and show your working. formula working Ω [2] (b) (i) The diagrams below show the circuit symbols for three components of an electric torch (flashlight). On the line below each diagram state the name of the component. [2] (ii) Using only these symbols draw a circuit diagram for a torch. [1]

12 © UCLES 2013 0654/22/M/J/13 For Examiner's Use (c) Complete the sentences to describe the energy transfers which take place when the torch (flashlight) is used. Choose from the words below. You may use each word once, more than once or not at all. chemical electrical kinetic light nuclear potential sound thermal energy is stored in the cells. This is transferred into energy which passes to the lamp. The useful energy output from the lamp is energy, but much energy is wasted as energy. [2] (d) A ray of light from the torch is reflected by a mirror. This is shown in Fig. 7.1. normal a b mirror Fig. 7.1 Angle a has a value of 45°. Name angle b and write down its value. name value ° [2]

13 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use 8 (a) The ovary of a flower contains one or more ovules. The ovules contain female gametes. After fertilisation, an ovule becomes a seed containing an embryo plant. Fig. 8.1 shows a pea seed developing inside a pod. pea seed A B C Fig.8.1 (i) Explain the meaning of each of the following terms. gamete fertilisation [2] (ii) Parts A and B in Fig. 8.1 remain from the flower. State the name of part A and function of part B of these parts in the flower. name of part A function of part B [2] (iii) Suggest the part of the flower from which structure C developed. [1]

14 © UCLES 2013 0654/22/M/J/13 For Examiner's Use (b) Four sets of pea seeds were placed in Petri dishes containing either damp soil or damp filter paper. They were left in different conditions, shown in Table 8.1. Table 8.1 set conditions A damp soil cold dark B damp filter paper warm light C damp filter paper warm dark D damp soil cold light Predict which sets of seeds will germinate. Explain your answer. prediction explanation [3] (c) A pea seed was planted in a pot. When the seed had grown into a young plant, the pot was placed on its side, in a room where light was coming from all sides. Fig. 8.2 shows the young pea plant three days after the pot had been placed on its side. Fig. 8.2 (i) Name the response shown by the pea plant in Fig. 8.2. [2]

15 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (ii) Suggest how this response will help the plant to reproduce sexually. [3]

16 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 9 (a) (i) Explain why hydrogen and carbon are described as elements, but hydrocarbons such as methane and ethane are described as compounds. [2] (ii) Complete the diagram below to show one molecule of methane. H C [2] (iii) Name the material found in the Earth that is the main source of methane. [1] (b) Ethene is a colourless gas made of hydrocarbon molecules. Fig. 9.2 shows diagrams of four hydrocarbon molecules, W, X, Y and Z. H C H C H H H H C C H H H H C H H C H C H H H H C H H C H H H H C H H C H H C H H C H W X Y Z Fig. 9.2 (i) State which diagram, W, X, Y or Z, represents one molecule of ethene. [1]

17 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (ii) State and explain which of the diagrams, W, X, Y or Z, represent molecules that are unsaturated. diagrams explanation [2] (c) When gaseous ethene is heated and pressurised, a white solid known as poly(ethene) is produced. (i) Describe briefly what occurs when ethene molecules react to form poly(ethene). You may wish to draw a simple diagram of a poly(ethene) molecule, using the symbol E to represent ethene. [2] (ii) State the full name of the type of chemical reaction that occurs to form poly(ethene). [2]

18 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 10 (a) Draw a straight line from each radiation to its correct use. killing cancer cells night vision glasses photographing bones γ (gamma) rays used for radiation X-rays [2] (b) X-rays and γ-rays are both examples of ionising radiation. Explain what is meant by the term ionising radiation. [1] (c) Some countries use nuclear fission in electricity power stations. What is meant by the term nuclear fission? [2]

19 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (d) The stages that take place in a nuclear power station generating electricity are shown in Table 10.1 below. Put the stages in the correct sequence by adding numbers 1, 3, 5 and 7 to the right hand column. Table 10.1 stage sequence A chain reaction happens in the core. A generator is turned. A turbine turns. 6 Electrical energy is generated. 8 Steam is produced. Thermal energy is produced. 2 Thermal energy is removed from core. Water is heated. 4 [3] (e) Which of these statements about the generation of electricity from nuclear fuel are correct? Tick (
) the two correct statements. no carbon dioxide is produced no dangerous waste is produced no fossil fuels are used no problems with the radioactive waste no thermal energy is wasted [2]

20 © UCLES 2013 0654/22/M/J/13 For Examiner's Use (f) A teacher demonstrated how the count rate detected by a Geiger-Müller tube depends on the distance between the front of the tube and a radioactive α (alpha) source. Fig. 10.1 shows how the equipment was set up. d cable to counter radioactive α source Geiger-Müller tube d = distance between source and Geiger-Müller tube Fig. 10.1 Fig. 10.2 shows a graph of the results of the experiment. 200 100 0 0 2 4 d / cm count rate / counts per minute 6 8 Fig. 10.2 (i) State the range of the alpha particles. cm [1] (ii) Describe how you would use the apparatus to obtain these results. [3]

21 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (iii) Before carrying out the experiment the teacher discussed how to reduce her exposure to radiation. Which idea below would not help reduce the radiation exposure of the teacher during the experiment? Explain your answer. idea 1 Hold the source with long tongs and wear gloves. idea 2 Place a lead shield between the source and the teacher. idea 3 Wear a photographic badge that detects radiation. idea because [2]

22 © UCLES 2013 0654/22/M/J/13 For Examiner's Use 11 Fig. 11.1 shows a food chain. The arrows show how energy flows from one organism to another, along the chain. man sheep grass Fig. 11.1 (a) Energy enters the food chain as sunlight. Plant leaves use this energy to make food. (i) Name the substance in the leaves of a plant that absorbs this energy. [1] (ii) Name the two raw materials that the plant uses to make food. 1 2 [2] (iii) Name the gas released from plant leaves during this process. [1] (b) A sheep is a herbivore. Define the term herbivore. [2] (c) Meat from the sheep contains protein. Describe the importance of protein in the diet. [2]

23 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use (d) In the cells of the plant, sheep and man, useful energy is released from the food by respiration. Some of the energy is released as heat. Explain why the following changes occur when the man's body temperature rises too high. The arterioles near the surface of his skin dilate. His sweat glands produce more sweat. [4]

24 © UCLES 2013 0654/22/M/J/13 BLANK PAGE

25 © UCLES 2013 0654/22/M/J/13 [Turn over For Examiner's Use 12 (a) A student added a solution of the same dilute acid to each of the test-tubes P to T shown in Fig. 12.1. P magnesium Q magnesium carbonate R copper carbonate S copper oxide T alkaline solution containing litmus Fig. 12.1 Complete Table 12.1 by matching the test-tubes, P, Q, R, S and T, with the observations which are made when the dilute acid reacts with the contents. Some of the observations could apply to more than one of the test-tubes. You may use each letter once, more than once or not at tall. Table 12.1 observations test-tube(s) The mixture turns red when excess acid has been added. A colourless gas is given off. A blue solution is formed. A colourless gas which pops when ignited is given off. [4]

26 © UCLES 2013 0654/22/M/J/13 For Examiner's Use (b) The student used the apparatus shown in Fig. 12.2 to investigate neutralisation reactions involving three acids, A, B and C. sodium hydroxide solution burette containing acid pH sensor beaker pH = tap to allow acid to run in Fig. 12.2 In each experiment, 25.0 cm3 of the same solution of sodium hydroxide were placed into a beaker. The tap on the burette was opened and acid was added slowly. The measurements made by the pH sensor were displayed on the computer screen. Some of the measurements from the three experiments are shown in Table 12.2. Table 12.2 acid source of acid volume required to produce a neutral mixture / cm3 A sample taken from an acidic lake 42.0 B sample taken from a car battery 15.0 C acid from a chemical laboratory 60.0 (i) Suggest a possible pH value of the alkali before any acid was added. [1] (ii) State, with a reason, which acid A, B or C, had the highest concentration. acid reason [1]

27 © UCLES 2013 0654/22/M/J/13 For Examiner's Use (iii) The student noticed that in all three experiments, the temperature of the mixture increased as the acid was added. Suggest why the temperature increased. [1] (iv) Complete the general word equation for the reaction which occurs between an acid and an alkali. acid alkali + + [2] (v) Sample A was taken from an acidic lake. Much of the acidity of the acidic lake is caused by sulfur dioxide gas dissolving and reacting with lake water. State two possible sources of the sulfur dioxide, one natural and one the result of human activity. natural human activity [2]

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 2013 0654/22/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 0654/22 Paper 2 (Core 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 22 © Cambridge International Examinations 2013 1 (a) (i) potassium hydroxide ; [1] (ii) rate increases down the group ; [1] (b) (i) increases down the group ; [1] (ii) mixture becomes orange ; bromine is produced ; chlorine is more reactive than bromine / chlorine displaces bromine ; [3] [Total: 6] 2 (a) force ; distance ; [2] (b) (density =) mass ÷ volume ; = 5000 / 5 = 1000 (kg / m3) ; [2] (c) (i) 20 Hz or below ; human lower threshold is about 20 Hz ; [2] (ii) number of vibrations per second ; [1] [Total: 7]

Page 3 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 22 © Cambridge International Examinations 2013 3 (a) (thread of) DNA ; contains genes ; [2] (b) (i) Hh no horns and hh horns ; [1] (ii) ;;; [3] (iii) look to see if any offspring have horns ; if they do the bull has the h allele ; [2] (iv) idea that the genetic diagrams show the chances of getting each kind of offspring ; bull could have h allele but all offspring get the H allele ; idea that the more offspring there are, the more likely that the h allele will show up ; [max 2] [Total: 10] phenotypes of parents genotype of parents gametes bull with no horns Hh and cow with horns hh gametes from cow gametes from bull H H h h h h Hh hh

Page 4 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 22 © Cambridge International Examinations 2013 4 (a) thermal ; thermal and conduction ; [2] (b) energy input throughout 5 minutes ; up to 100 °C energy increase the KE of the particles (in liquid) ; water boils at 100 °C ; energy used to separate water molecules not for more KE ; reference to Latent Heat ; [max 3] (c) random arrangement ; mostly touching ; [2] [Total: 7] 5 (a) (i) sodium chloride and sodium oxide ; [1] (ii) sodium atom loses an electron / outer shell ; chlorine atom gains an electron / fills outer shell ; [2] (iii) ions have opposite charges / opposite charges attract ; [1] (iv) ionic always solid (at room temperature), covalent can be liquids and gases ; ionic often soluble in water, covalent tend to be insoluble in water ; ionics can form electrolytes, covalent cannot be electrolytes ; [max 2] (b) (i) anode labelled ; [1] (ii) P oxygen ; Q hydrogen ; [2] (iii) (hydrogen) lighted splint ; pops ; OR (oxygen) glowing splint ; relights ; [max 2] [Total: 11]

Page 5 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 22 © Cambridge International Examinations 2013 6 (a) reference to haemoglobin ; haemoglobin combines with oxygen ; picks up oxygen in lungs and drops it in tissues ; [max 2] (b) protection against disease / destroys invading microorganisms; phagocytosis ; takes in and digests bacteria ; [max 2] (c) delivers, oxygen / nutrients ; removes waste materials / carbon dioxide ; to / from, body tissues / cells ; [max 2] [Total: 6] 7 (a) R = R1 + R2 ; = 1200 + 2400 = 3600 (Ω) ; [2] (b) (i) lamp cell switch (3 correct = 2 marks 2 correct = 1 mark) ;; [max 2] (ii) correct series circuit and all symbols correct ; [1] (c) chemical ; electrical ; light ; thermal ; (any two for 1 mark) [max 2] (d) angle of reflection ; 45° ; [max 2] [Total: 9] 8 (a) (i) (gamete) a sex cell ; (fertilisation) joining of nuclei of, male and female gametes / sex cells ; [2] (ii) sepal ; produces pollen / male gametes ; [2] (iii) ovary (wall) ; [1] (b) B and C ; they have warmth ; they have water ; light is not needed ; [max 3]

Page 6 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 22 © Cambridge International Examinations 2013 (c) (i) tropism ; (negative) geotropism / gravitropism ; [2] (ii) reference to photosynthesis ; leaves can get more light ; flowers held up ; where insects can reach them ; [max 3] [Total: 13] 9 (a) (i) H and C / elements contain only one type of atom ; compound contains different atoms that are bonded ; elements shown in Periodic Table compounds not shown ; [max 2] (ii) 1 × C and 4 × H ; correctly bonded ; [2] (iii) natural gas ; [1] (b) (i) Z ; [1] (ii) X, Z ; unsaturated molecules contain double bonds ; [2] (c) (i) ethene molecules link together ; to form (long) chains ; [2] (clear diagram could score both marks) (ii) addition ; polymerisation ; [2] [Total: 12] 10 (a) gamma – killing cancer cells ; X-rays – photographing bones ; [2] (b) removes electrons from atoms / turns atoms into ions ; [1] (c) breaking up / splitting ; of nucleus (of atom) ; [2]

Page 7 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 22 © Cambridge International Examinations 2013 (d) stage order A chain reaction happens in the core. 1 A generator is turned 7 A turbine turns 6 Electrical energy is generated. 8 Steam is produced. 5 Thermal energy is produced. 2 Thermal energy is removed from core. 3 Water is heated. 4 1 in first box ; 7 in second box ; [3] 5 in third box and 3 in fourth box ; (e) no carbon dioxide is produced √ no dangerous waste produced no fossil fuels are used √ no problems with the radioactive waste no thermal energy is wasted ;; [2] (f) (i) 5 cm ; [1] (ii) measure separation and record count rate ; measure count for one minute ; repeat reading and take mean ; change separation distance and repeat ; reference to dealing with background radiation ; [max 3] (iii) idea 3 ; this detects radiation (but does not reduce exposure) ; [2] [Total: 16]

Page 8 Mark Scheme Syllabus Paper IGCSE – May/June 2013 0654 22 © Cambridge International Examinations 2013 11 (a) (i) chlorophyll ; [1] (ii) carbon dioxide ; water ; [2] (iii) oxygen ; [1] (b) an animal that gets its energy ; (from) only eating plants ; [2] (c) growth / repair ; for making, cell membranes / cytoplasm ; for making enzymes / haemoglobin / antibodies / other specific substance ; [max 2] (d) (arterioles dilate) (max 2) more blood carried close to the skin surface ; allows more heat to be lost ; by radiation ; AND (more sweat produced) (max 2) water in sweat evaporates ; reference to latent heat of evaporation ; heat lost ; [max 4] [Total: 12] 12 (a) T ; P Q R ; R (S) ; P ; [4] (b) (i) 8 – 14 ; [1] (ii) (B) took the least volume to neutralise the alkali ; [1] (iii) reaction was exothermic / heat energy transferred to mixture ; [1] (iv) salt ; + water ; [2] (v) volcanic activity ; burning (fuel containing) sulfur compounds ; [2] [Total: 11]