IGCSE Combined Science Paper2b 2003

This document consists of 15 printed pages and 1 blank pages. SP (BR/PW) S42588/2 © UCLES 2003 [Turn over CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/02 Paper 2 October/November 2003 1 hour 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 in the spaces provided on the Question Paper. 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. Answer all questions. 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. A copy of the Periodic Table is printed on page 16. Centre Number Candidate Number Name If you have been given a label, look at the details. If any details are incorrect or missing, please fill in your correct details in the space given at the top of this page. Stick your personal label here, if provided. For Examiner’s Use 123456789 Total2 0653/02/O/N/03 1 Windfarms are areas of land containing many wind turbines. Four thousand wind turbines can produce the same power as one coal-fired power station. (a) (i) State the main energy change that takes place in a wind turbine. ............................... energy → ............................... energy [1] (ii) Complete the sequence of energy changes in a coal-fired power station. → → → [2] (b) Wind power is said to be a renewable source of energy. Explain what the term renewable means. ......................................................................................................................................... .....................................................................................................................................[1] (c) Nuclear fission is used to produce electricity in nuclear power stations. The Sun’s energy is produced by nuclear fusion. Explain the difference between nuclear fission and nuclear fusion. ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[2] For Examiner’s Use .................. energy heat energy kinetic energy .................. energy3 0653/02/O/N/03 [Turn over 2 A boy went to his doctor because he felt tired all the time. His doctor took a sample of his blood. The doctor tested the blood. She found that the boy did not have enough red blood cells. The doctor told the boy that he was suffering from anaemia. She explained to the boy that he should eat more iron in his diet. (a) (i) What do red blood cells do? .................................................................................................................................. ...............................................................................................................................1] (ii) Explain why not having enough red blood cells made the boy feel tired. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] (b) (i) Explain why eating more iron would help the boy to increase the number of red blood cells in his body. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] (ii) The boy asked his doctor to tell him which kinds of foods he should eat, in order to get more iron. Name two foods that she might have suggested. ...............................................................................................................................2] For Examiner’s Use4 0653/02/O/N/03 3 (a) (i) The formula of chlorine molecules is Cl2. Explain what this formula means. .................................................................................................................................. ...............................................................................................................................1] (ii) An atom of chlorine has a proton number of 17 and a nucleon number of 35. A diagram of this chlorine atom is shown in Fig. 3.1. Complete the labelling of the diagram. [3] Fig. 3.1 (b) Explain why chlorine is sometimes used to treat drinking water before it is supplied to homes. ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[2] X XX X XX X X X X X X X XX XX nucleus containing 17 and neutrons For Examiner’s Use5 0653/02/O/N/03 [Turn over 4 Fig. 4.1 shows an electrical device. Fig. 4.1 (a) Name this device. .....................................................................................................................................[1] (b) Calculate the output voltage. Show your working and state any formula that you use. formula working ................................................ volts [2] (c) Electricity is transmitted for long distances through cables. Why does the voltage need to be high for transmission over long distances? ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[2] (d) An electricity supply is 240 V a.c. The frequency of the electricity supply is 50 Hz. Explain the meaning of the following terms. (i) a.c. ........................................................................................................................... ...............................................................................................................................2] (ii) Hz ............................................................................................................................ ...............................................................................................................................1] primary coil 10 turns 24V a.c. secondary coil 200 turns For Examiner’s Use6 0653/02/O/N/03 5 The words on the left in Fig. 5.1 are ecological terms. (a) Match each word with its definition by drawing a line between them. One has been done for you. Fig. 5.1 [2] ecosystem community consumer population all living organisms in a habitat all the organisms of one species in a habitat living organisms and their environment an organism that feeds on other organisms For Examiner’s Use7 0653/02/O/N/03 [Turn over (b) A student investigated the population of snails in a wood. She collected 50 snails, and measured the shell length of each one. She also recorded the number of stripes on their shells. Fig. 5.2 shows the graphs that she drew to display her results. Fig. 5.2 (i) The student thought that the variation in the length of the snail shells could be caused by their environment. Suggest one environmental factor that could cause the variation in the length of the snail shells. ...............................................................................................................................1] (ii) The student thought that the variation in the number of stripes was probably caused by the snails’ genes. The student was able to keep the snails for many months in order to investigate this. What should she do, and what result should she look for? .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] number of snails 25 20 15 10500 2 4 6 8 10 12 14 shell length/mm number of snails 25 20 15 1050 0 2 number of stripes 1 3 For Examiner’s Use8 0653/02/O/N/03 6 In a car engine, fuel containing hydrocarbons reacts with oxygen from the air. The products of this reaction enter the air with the exhaust gases. (a) (i) Name the element that makes up nearly 79 % of the air. ...............................................................................................................................1] (ii) The gas argon is present in air. Explain why argon does not react with the hydrocarbon fuel in the car engine. .................................................................................................................................. ...............................................................................................................................1] (iii) Explain why it is very dangerous to leave a car engine running inside a closed building. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] (b) The energy needed to launch a space shuttle is released when a mixture of hydrogen and oxygen react to form the compound water. (i) The symbolic equation for this reaction is shown below. 2H2+O2→2H2O This equation is said to be balanced. Explain what this means. .................................................................................................................................. ...............................................................................................................................1] (ii) Describe one way in which a mixture of two gaseous elements is different from a compound of the same elements. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................1] car exhaust gases air drawn into the car engine For Examiner’s Use9 0653/02/O/N/03 [Turn over (c) Suggest why the use of hydrogen as a car fuel would cause less air pollution than the use of hydrocarbon fuels. ......................................................................................................................................... ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[2] [Question 7 can be found on page 10] For Examiner’s Use10 0653/02/O/N/03 7 Fig. 7.1 shows a racing car. It is designed to accelerate rapidly and to go very fast. Fig. 7.1 (a) The car took 1.2 hours to complete a race of 288 kilometres. Calculate the average speed of the car in kilometres per hour. Show your working and state any formula that you use. formula working ................................... km /h [2] For Examiner’s Use11 0653/02/O/N/03 [Turn over (b) A speed/time graph for the car is shown in Fig. 7.2. It shows the motion of the car over a 26 second period. Fig. 7.2 (i) At which point is the car not moving? ...............................................................................................................................1] (ii) State one part of the graph when the car was travelling at a constant speed. Explain your answer. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] (iii) State one part of the graph when the car was slowing down. ...............................................................................................................................1] 120 100 80 60 40 2000 2 4 6 8 10 12 14 16 18 20 22 24 26 28 speed m per s time/s B C D E F G A For Examiner’s Use12 0653/02/O/N/03 8 Fig. 8.1 shows the structure of the contents of the human thorax (chest). Fig. 8.1 (a) On Fig. 8.1, draw label lines to each of the following structures and label them with the appropriate letter. A a pleural membrane B a bronchus C the place where gas exchange takes place D the heart [4] For Examiner’s Use13 0653/02/O/N/03 (b) The lining of the trachea contains • goblet cells and • cells with cilia. (i) Describe how these cells help to keep the lungs clean. .................................................................................................................................. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] (ii) Explain how smoking can lead to the development of bronchitis. .................................................................................................................................. .................................................................................................................................. .................................................................................................................................. ...............................................................................................................................2] [Question 9 can be found on page 14] For Examiner’s Use [Turn over14 0653/02/O/N/03 For Examiner’s Use 9 (a) Choose words from the list below to complete the passage. Each word is used once or not at all. aluminium electrolyte positive anode iron solution cathode negative sulphur Electrolysis is a process used in industry to make important elements such as ................................ . In electrolysis a pair of electrodes dip into a liquid called an ................................. . Metal ions have a ............................. charge and are attracted towards the ............................ . [4] (b) (i) Describe one observation that would be made during the electrolysis of copper chloride solution. .................................................................................................................................. ...............................................................................................................................1] (ii) In electrolysis, compounds are split into their elements. Complete the word chemical equation for the reaction that occurs in the electrolysis of copper chloride solution. copper chloride→ [1]15 0653/02/O/N/03 BLANK PAGE16 0653/02/O/N/03 Group DATA SHEET The Periodic Table of the Elements 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.). aX b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series †90-103 Actinoid series