Cambridge IGCSE Science - Combined 0653 — 2008 Oct/Nov Paper 2 · Variant 1

This document consists of 18 printed pages and 2 blank pages. IB08 11_0653_02/3RP © UCLES 2008 [Turn over *3172895510* 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 COMBINED SCIENCE 0653/02 Paper 2 (Core) October/November 2008 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 20. 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 2008 0653/02/O/N/08 For Examiner's Use 1 Fig. 1.1 shows a food web. mice pigeons insects small birds hawks plant seeds plant leaves caterpillars Fig. 1.1 (a) (i) State what the arrows in Fig. 1.1 represent. [1] (ii) State the numbers of different producers and consumers named in this food web. producers consumers [1] (iii) No decomposers are shown in the food web. Which organisms in the web provide food for decomposers? [1]

3 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use (b) The plant seeds that a mouse eats are digested in its alimentary canal. (i) Explain what digestion is, and why digestion is necessary. [2] (ii) State two ways by which food is digested in the alimentary canal. 1 2 [2] (c) When an insect respires, it releases carbon dioxide into the air. Describe how this carbon dioxide could become part of a glucose molecule in a plant leaf. [2]

4 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 2 (a) An inflatable ball is floating on the sea without moving. air sea ball Fig. 2.1 (i) On Fig. 2.1 draw arrows to represent the two forces acting. Label each force with its name. [2] (ii) Are these two forces balanced or unbalanced? Explain your answer. [1] (b) Three waves reach a nearby beach in ten seconds. State the frequency of the waves. Hz [1] (c) The power of the waves can be used as a renewable source of energy. (i) Suggest how the motion of the waves could be converted into electrical energy. [2] (ii) Suggest one other renewable source for generating electricity. [1]

5 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use (d) People on the beach are exposed to many forms of electromagnetic radiation. Which type of electromagnetic radiation causes the skin to tan? [1] (e) Someone has left a glass bottle on the beach. The curved glass acts like a lens focussing the sun’s rays. Complete the light rays on Fig. 2.2 to show what happens to rays of light after they have passed through a convex lens. Fig. 2.2 [2]

6 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 3 (a) Fig. 3.1 shows two cars A and B. Car A produces exhaust gases which appear black. The exhaust gases from car B cannot be seen. Both cars have engines which use diesel (gas oil) which is a hydrocarbon fuel. car A car B Fig. 3.1 (i) Name the raw material from which hydrocarbon fuels like diesel are obtained. [1] (ii) Gasoline (petrol) is another liquid hydrocarbon fuel used in cars. Gasoline and diesel are obtained by the process of fractional distillation. State one difference between the properties of diesel and of gasoline which allows them to be separated by fractional distillation. [1] (iii) Name two compounds which are produced when hydrocarbons undergo complete combustion. 1 2 [2] (iv) Describe briefly how exhaust gases are thought to be contributing to climate changes. [2]

7 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use (b) The energy needed to move cars is provided by the combustion of the fuel. Air must be supplied to the engine for this combustion to occur. Fig. 3.2 shows a bar chart of the main gases in a sample of dry air. 90 80 70 60 50 40 30 20 10 0 % by volume R S argon carbon dioxide gases Fig. 3.2 (i) Name gases R and S in Fig. 3.2. gas R gas S [2] (ii) Air contains small amounts of the gases argon and carbon monoxide. The amount of argon is typically much greater than that of the toxic gas carbon monoxide. Explain why the argon in air is not harmful to humans. [2]

8 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 4 A girl is competing in a 100 m race. (a) (i) The girl completes the race in 14.4 seconds. Calculate her average speed. State the formula that you use and show your working. formula working m / s [2] (ii) During the first three seconds of the race the girl runs with constant acceleration from a speed of 0 m / s to a speed of 5 m / s. Calculate her acceleration. State the formula that you use and show your working. formula working m / s2 [2] (b) The girl then competes in the high jump. Just before she reaches the bar she begins to move upwards. Describe the energy changes that take place between the girl taking off and landing after the jump. [3]

9 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use 5 This article appeared in a newspaper in Pakistan in 2006. Many more people in Pakistan and India are developing diabetes. This is an illness where the regulation of blood glucose does not work properly. Doctors think that the increase in diabetes is happening because people are eating more fast food. Where they used to eat a lot of rice and lentils, they are now eating more fried foods and greasy take-aways. As well as increasing the risk of diabetes, this diet is causing an increase in obesity. This also increases the risk of heart disease. (a) (i) Name the hormone that is produced when the blood glucose level rises, and which helps to bring it back down to normal. [1] (ii) Name the gland that secretes this hormone. [1] (iii) Describe how the hormone reduces the amount of glucose in the blood. [2] (b) (i) Suggest why eating foods containing a lot of fat, rather than eating lentils and rice, can lead to a person becoming overweight. [2] (ii) An overweight person has an increased risk that a blockage will occur in a coronary artery. Explain how a blockage in a coronary artery could cause a heart attack. [2]

10 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 6 The chemical symbols for two elements are shown below. Mg 24 12 O 16 8 These symbols represent one atom of each element. (a) (i) Name the three smaller particles which make up these atoms. [1] (ii) What do the numbers 12 and 24 indicate about the structure of one atom of magnesium? [2] (b) A student used the apparatus in Fig. 6.1 to burn magnesium in air. heat crucible magnesium Fig. 6.1 As a result of the reaction, the piece of magnesium changed into a white solid. The balanced equation for the reaction is shown below. 2Mg + O2 → 2MgO (i) Write the word equation for this reaction. [1] (ii) Write the name or formula of the substance shown above in the equation which contains ionic bonds. Explain your answer briefly. substance explanation [2]

11 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use (c) The student then added some magnesium to some dilute sulphuric acid contained in test-tube A. He also added some of the white solid produced by the reaction in (b) to some dilute sulphuric acid in test-tube B as shown in Fig. 6.2. dilute sulphuric acid test-tube A test-tube B magnesium white solid Fig. 6.2 At the end of the reactions a colourless solution remained in both test tubes. (i) One of the reactions in Fig. 6.2 produced a gas. In which test-tube, A or B, were gas bubbles observed? Explain your answer. test-tube explanation [2] (ii) The formula of the gas produced in (i) is H2. State and explain whether this gas is an element or a compound. [1] (iii) After the reactions had finished, both test-tubes contained the same compounds. One of these was water. Name the other compound present in both tubes. [1]

12 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 7 (a) The radioactive emissions from a sample of radon–220 were investigated. The radiation emitted was measured every hour for 10 hours. State the apparatus needed for this. [1] (b) Radon is a gas that emits alpha radiation. Explain why alpha radiation is dangerous to human beings. [2] (c) Radioactivity can be useful to humans. Apart from the generation of electricity, describe one use of radioactivity. [2]

13 0653/02/O/N/08 [Turn over BLANK PAGE Please turn over for Question 8

14 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 8 Fig. 8.1 shows part of the male reproductive system. A B C D Fig. 8.1 (a) Give the letter of each of these parts. (i) where sperm are made (ii) where urine is stored (iii) the ureter (iv) the urethra [4] (b) On Fig. 8.1, write the letter X to show the part of the reproductive system which is cut or tied when a man has a sterilisation operation. [1]

15 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use (c) Fig. 8.2 shows a sperm. Fig. 8.2 (i) On Fig. 8.2, name and label two structures that are found in all animal cells. [2] (ii) Describe two ways in which a sperm is adapted for its function. 1 2 [2]

16 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 9 (a) Fig. 9.1 shows part of the Periodic Table. The letters are not the chemical symbols of elements. A E F G B C D H Fig. 9.1 Choose one of the letters from A to H, which shows an element whose atoms have only one electron shell, [1] an element in the same period as element D. [1] (b) Calcium carbonate, CaCO3 , is an important compound used in many industries. A student used the apparatus in Fig. 9.2 to investigate what happens when calcium carbonate is heated strongly. strong heat calcium carbonate tube T limewater Fig. 9.2 During the experiment many gas bubbles passed through the limewater, which turned cloudy. A white solid remained in tube T after the student stopped heating. (i) Complete the word equation for the reaction. calcium carbonate → calcium oxide + [1]

17 © UCLES 2008 0653/02/O/N/08 [Turn over For Examiner's Use (ii) State the type of chemical reaction that occurs when calcium carbonate is heated strongly. [1] (iii) Describe how the student could test the solid which remained in tube T to find out if all the calcium carbonate had reacted. [3]

18 © UCLES 2008 0653/02/O/N/08 For Examiner's Use 10 (a) (i) The diagram in Fig. 10.1 shows a circuit with a two-way switch, S. S R P Q Fig. 10.1 Complete the table below to show if each lamp is on or off when switch S is in the position shown. Write ‘on’ or ‘off’ for each lamp. lamp on or off P Q R [2] (ii) Name the component in the circuit which provides the energy for the circuit. [1] (b) A student has three resistors as shown in Fig. 10.2. 2 Ω 4 Ω 6 Ω Fig. 10.2 Explain how he can combine two of these resistors to get a total resistance of 10 ohms. [2]

20 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 2008 0653/02/O/N/08 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 Sulphur 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 2008 question paper 0653 COMBINED SCIENCE 0653/02 Paper 2 (Core Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began. All Examiners are instructed that alternative correct answers and unexpected approaches in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. 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 2008 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 Syllabus Paper IGCSE – October/November 2008 0653 2 © UCLES 2008 1 (a) (i) energy transfer ; [1] (ii) 2 producers and 6 consumers ; [1] (iii) all of them ; [1] (b) (i) breaking down food / large molecules / compounds ; so that it / they can be absorbed / more easily get into the blood ; [2] (ii) by teeth / chewing / grinding / mechanical / physical digestion ; by enzymes ; (allow two marks for two enzymes with correct detail) [2] (c) carbon dioxide from air (into plant leaf) ; photosynthesis (in plant) ; combines carbon dioxide with water ; (produces glucose) in chloroplast ; [max 2] [Total: 9] 2 (a) (i) arrows vertically downward and upward ; labeled weight / gravitational pull and upthrust ; [2] (ii) balanced (no mark) ball isn’t accelerating / decelerating / changing speed ; [1] (b) 0.3 ; [1] (c) (i) (up/down) motion / kinetic / movement energy of waves (produces movement) ; which makes generator turn to produce electricity / moves magnet in a coil / moves a turbine ; [2] (ii) solar / sunlight ; HEP ; geothermal ; wind ; tides ; biomass ; [max 1] (d) UV ; [1] (e) rays are straight lines ; rays come to a focus somewhere between the line of incident rays; [2] [Total: 10]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0653 2 © UCLES 2008 3 (a) (i) crude oil / petroleum ; [1] (ii) boiling point / boiling range / other correct ; [1] (iii) carbon dioxide ; water ; [2] (iv) reference to carbon dioxide (levels increasing / out of balance) ; carbon dioxide able to trap (radiant) heat / description of process ; reference to greenhouse effect / global warming ; [2 max] (b) (i) R – nitrogen ; S – oxygen ; (allow one mark if both names given but reversed) [2] (ii) (argon is a) noble gas / unreactive (with body tissue) / stable ; atoms have full outer shell ; [2] [Total: 10] 4 (a) (i) (speed =) distance ÷ time / (S =) D ÷ T ; (accept recognised symbols but not units in the formula) (= 100/14.4) = 6.94 (m/s) ; [2] (ii) (acceleration =) change of speed ÷ time ; (accept recognised symbols but not units in the formula) (= 5 ÷ 3 =) 1.67 (m/s2) ; [2] (b) kinetic energy changes into potential (as she jumps up) ; at top of jump only potential energy ; potential energy changes to kinetic energy coming down ; kinetic energy lost as sound/heat on landing ; chemical energy to kinetic energy within a correct context ; [max 3] [Total: 7]

Page 4 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0653 2 © UCLES 2008 5 (a) (i) insulin ; [1] (ii) pancreas ; [1] (iii) affects liver ; which removes glucose (from the blood) ; (liver) stores it as glycogen / changes it into glycogen (within liver) / glycogen produced ; [max 2] (b) (i) a lot of, energy / calories / kilojoules, in fat ; lentils and rice mostly carbohydrate ; less energy per gram in carbohydrates than fat ; [max 2] (ii) stops blood getting to heart muscle ; so heart muscle is short of oxygen / oxygenated blood; general ref. to respiration ; (implied heart) muscle stops working ; [max 2] [Total: 8] 6 (a) (i) protons neutrons electrons ; [1] (ii) atoms contain 12 protons ; (reject 12 electrons) and 12 neutrons ; nucleus contains 24 nucleons ; [2 max] (reject relative atomic mass is 24) (b) (i) magnesium + oxygen → magnesium oxide ; [1] (ii) magnesium oxide / MgO ; metal bonded to non-metal ; (accept description in terms of electron transfer) [2] (c) (i) (A) reaction is between metal and an acid ; which produces hydrogen gas ; [2] (ii) (element) only contains one type of atom / only one kind of chemical symbol / a compound is two or more elements joined together / has a formula with more than one chemical symbol; hydrogen / H is found in the Periodic Table ; cannot be broken down simplified ; [1 max] (iii) magnesium sulphate / (excess) sulphuric acid; [1] (accept correct formulae of these substances) [Total: 10]

Page 5 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0653 2 © UCLES 2008 7 (a) Geiger-Muller / GM tube (detector) / counter/scalar (measurer) / spark counter ; [1] (accept any detector even if non-quantitative) (b) only dangerous if breathed in or ingested / ionising radiation ; helium nuclei / large particles ; highly ionising ; (ionisation occurs when) electrons removed (from atoms or molecules) ; damages / cells / DNA / causes mutations ; causes cancer ; kills cells ; [2 max] (c) use ; description ; [2] e.g. sterilising hospital equipment ; radiation destroys germs/bacteria on instruments ; e.g. measurement of thicknesses ; thickness related to % of radiation penetrating ; e.g. use of radioisotopes in medical context / used in medicine / in hospitals ; as tracers / selectively absorbed by organs for diagnosis or cure ; (reject any ref. to weaponry) [Total: 5] 8 (a) (i) D ; (ii) B ; (iii) C ; (iv) A ; [4] (b) X on sperm duct close to testis ; [1] (allow anywhere from top of testis to where sperm duct goes behind bladder but not on urethra) (c) (i) labels to cell membrane ; nucleus ; cytoplasm ; [max 2] (ii) tail for swimming ; only 23 chromosomes / half usual number of chromosomes, so correct number after fertilisation ; small size so less energy needed to swim ; streamlined so that it can move more easily ; enzymes in head to digest a way into the egg ; [max 2] [Total: 9]

Page 6 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0653 2 © UCLES 2008 9 (a) (i) A ; H or G ; [2] (b) (i) (calcium carbonate → calcium oxide +) carbon dioxide ; [1] (CO2 not acceptable as alternative) (ii) (thermal) decomposition ; [1] (iii) add (dilute) acid / further strong heat ; bubbles of gas which turn limewater milky ; then not all calcium carbonate has reacted/ora ; [3] [Total: 7] 10 (a) (i) on off on ;; (all correct = 2, two correct = 1) [2] (ii) cell/battery ; [1] (b) 6 Ω and 4 Ω ; in series ; [2] [Total: 5]