Cambridge IGCSE Science - Combined 0653 — 2010 May/June Paper 2 · Variant 1

This document consists of 22 printed pages and 2 blank pages. IB10 06_0653_21/6RP © UCLES 2010 [Turn over *7983516015* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/21 Paper 2 (Core) May/June 2010 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 24. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 1 Fig. 1.1 shows some of the animals and plants that live in or close to a pond. water vole heron water snail bream pike insect larva not to scale pond weed Fig. 1.1 (a) Choose the correct term from the list below for each of the following descriptions. community decomposer ecosystem habitat photosynthesis population all the animals and plants that live in and around the pond all the water voles living in and around the pond all the living things, and their environment, interacting with each other [3]

3 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (b) The pond weed is a producer. Water snails and water voles are primary consumers. The heron and pike are secondary consumers. Complete the diagram of a food web that includes only these five organisms. pond weed [3] (c) The pond is at the bottom of a sloping field which was ploughed. During very heavy rain, a lot of soil from the field was washed into the pond. It made the water cloudy and stopped the light from reaching the leaves of the water plants, so that the plants died. After a while, the fish and other animals also died. Give two reasons why the fish and other animals died. 1 2 [2]

4 © UCLES 2010 0653/21/M/J/10 For Examiner's Use (d) Fig. 1.2 shows a cell from the pond weed. B A C D F E Fig. 1.2 (i) Give the letter of the part of the cell that controls what enters and leaves the cell, is the place where photosynthesis happens, contains DNA. [3] (ii) Describe two ways in which a cell from the heron would look different from the cell in Fig. 1.2. 1 2 [2]

5 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use 2 (a) Alpha, beta and gamma are three types of radiation emitted during radioactive decay. Name a suitable detector for these three types of radiation. [1] (b) State two hazards to the human body from exposure to radiation. 1 2 [2] (c) (i) Complete the table to compare alpha, beta and gamma radiations. Tick one box in each of the two rows in the table. alpha beta gamma most penetrating most ionising [2] (ii) State which type of radiation consists of particles with the greatest mass, consists of electromagnetic waves. [2]

6 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 3 Aluminium, iron and sodium are metallic elements. Aluminium and iron are widely used, but no useful objects can be made out of metallic sodium. aluminium alloys are used in aircraft iron is used to make steel for cars (a) (i) State one property of a metallic element which is different from a non-metallic element. [1] (ii) Use your knowledge of the metals in Group I of the Periodic Table to state one reason, other than cost, why no useful objects can be made out of metallic sodium. [1] (b) Aluminium and iron are mainly found as their oxides in rocks. (i) In order to obtain metallic iron, iron oxide is heated strongly in a furnace with carbon monoxide. One reaction which occurs in the furnace has the symbolic chemical equation shown below. Fe2O3 + 3CO → 2Fe + 3CO2 Explain whether or not this equation is balanced. [2] (ii) State the formula of the compound which has been reduced in the equation in (i). Explain your answer. formula explanation [2]

7 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (c) Aluminium is produced by electrolysis in which the electrolyte contains molten aluminium oxide. Aluminium oxide is a compound of a metal with a non-metal. (i) Name the type of chemical bonding found in aluminium oxide. [1] (ii) State the meaning of the term electrolyte. [1] (iii) State the type of energy which must be supplied to decompose molten aluminium oxide. [1] (iv) Name one other metal which is produced industrially by electrolysis. [1]

8 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 4 Fig. 4.1 shows part of the human nervous system. spinal cord Fig. 4.1 (a) The spinal cord is part of the central nervous system. (i) On Fig. 4.1, label and name one other part of the central nervous system. [1] (ii) Complete the sentences below. When a receptor receives a stimulus, signals pass along to the central nervous system. They then pass to which respond to the stimulus. [2] (b) Messages can also be passed from one part of the body to another in the form of hormones. Name the type of gland that produces hormones. [1] (c) A hormone secreted by the pancreas helps to keep blood sugar levels constant. (i) On Fig. 4.1, write the letter P to show the position of the pancreas in the body. [1] (ii) Name the hormone that reduces the blood sugar level if it gets too high. [1] (iii) Which body organ removes extra glucose from the blood when the blood sugar level gets too high? [1]

9 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (iv) Suggest why it is harmful to the body if the blood sugar level falls very low. [2]

10 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 5 Fig. 5.1 shows two dolphins communicating with each other using sound waves. Fig. 5.1 (a) How does a sound wave travel through water? [1] (b) Sound travels at different speeds through different substances. substance speed of sound (m/s) air 340 steel 5200 water 1500 (i) Does sound travel fastest in a solid, a liquid or a gas? [1] (ii) It takes 0.5 seconds for the sound wave to travel from one dolphin to the other. Calculate the distance between the two dolphins. State the formula that you use and show your working. formula working m [2]

11 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (c) A student is measuring the density of water. (i) Name a piece of apparatus he could use to measure the volume of the water. [1] (ii) Name the piece of apparatus he could use to measure the mass of the water. [1] (iii) Complete the formula that he would use to calculate the density. density = [1]

12 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 6 Fig. 6.1 shows samples of three of the elements in Group VII (Group 7) of the Periodic Table. X Y Z Fig. 6.1 (a) The elements in Fig. 6.1 are at the same temperature. One element is a solid, one is a liquid and one is a gas. (i) State which element, X, Y or Z, has the highest melting point. [1] (ii) Suggest the names of the elements, X, Y and Z. X Y Z [2] (b) An atom of fluorine has a proton (atomic) number of 9 and a nucleon (mass) number of 19. (i) A diagram of this fluorine atom is shown in Fig. 6.2. Complete the labelling of the diagram by writing the words electrons, neutrons and protons in the spaces. × × × × × × × × × nucleus contains … and … … [1] Fig. 6.2

13 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (ii) State the number of neutrons in the fluorine atom in Fig. 6.2. [1] (iii) Explain why the nucleus of an atom has almost the same mass as the whole atom. [1] (c) Many people use solutions which contain chlorine to clean some parts of their homes. Suggest one advantage of using a solution containing chlorine rather than water alone when cleaning homes. [2]

14 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 7 An investigation was carried out in Tamil Nadu, India, into the best conditions for growing tomatoes. The tomato plants were grown in unheated glasshouses or outside. Netting was used to provide shade in one of the glasshouses. glasshouse A glasshouse B outside no shade all four side walls shaded no shade Table 7.1 shows the mean temperature, and the mass of tomatoes produced, in the two glasshouses and outside. Table 7.1 mean temperature / ºC mass of tomatoes produced per plant / g glasshouse A 38 1020 glasshouse B 36 2310 outside 34 1380 (a) Which temperature gave the greatest mass of tomatoes? ºC [1] (b) Use your knowledge of convection to explain why the air inside the glasshouses stayed warmer than the air outside. [2]

15 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (c) Tomatoes are a fruit, produced from the fertilised flowers of tomato plants. Bees are most active in temperatures between 35 ºC and 36 ºC. Suggest why the mass of tomatoes produced was greater in glasshouse B than in glasshouse A. [2] (d) Suggest two factors, other than temperature, that could account for the lower mass of tomatoes produced outside than in glasshouse B. 1 2 [2]

16 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 8 (a) (i) The air is a mixture of gases. Complete Table 8.1 to show the percentages of the two main gases in the air. Table 8.1 name of gas percentage in the air oxygen nitrogen [2] (ii) Name one other gas which is found in unpolluted air. [1] (b) Sulfur dioxide is a gas which causes air pollution. Sulfur dioxide enters the air when volcanoes erupt. (i) Write the chemical formula of sulfur dioxide. [1] (ii) Describe one environmental problem which can occur when large amounts of sulfur dioxide are released into the air. [2]

17 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (c) When gasoline burns, the two main gases which are formed are carbon dioxide and water vapour. Both of these compounds are made of non-metallic elements bonded together. (i) Name the type of chemical bonding in molecules of carbon dioxide and water. [1] (ii) The displayed (graphical) formula of a water molecule is shown below. H — O — H Draw the displayed formula of a carbon dioxide molecule. [2]

18 © UCLES 2010 0653/21/M/J/10 For Examiner's Use 9 (a) A rider on his bicycle roll down a constant slope onto level ground. The rider uses the brakes to stop the bicycle. Fig. 9.1 shows the motion of the bicycle. 0 5 10 15 8 6 4 2 0 speed / m per s time / s D A B C A B C Fig. 9.1 (i) Over which section of the graph was the speed of the bicycle constant? [1] (ii) How long did it take the bicycle to stop after the brakes were used? s [1]

19 © UCLES 2010 0653/21/M/J/10 [Turn over For Examiner's Use (b) As the bicycle moves along a level road, the brakes are suddenly applied. The bicycle comes to a stop after 10 m. When the brakes are applied, the average frictional force stopping the bicycle is 250 N. Work is done and energy is transferred. (i) Calculate the work done as the bicycle slows down to a stop. State the formula that you use and show your working. formula working J [2] (ii) Identify the energy transfer which takes place. from energy to energy [2]

20 © UCLES 2010 0653/21/M/J/10 For Examiner's Use (c) Fig. 9.2 shows a bicycle with two lamps at the front. Fig. 9.2 Fig. 9.3 shows the circuit used to power the two lamps. lamp 1 lamp 2 Fig. 9.3 (i) What name is given to this type of circuit? [1] (ii) The resistance of each lamp in the circuit is 4 Ω. State the combined resistance of the two lamps. Ω [1]

21 © UCLES 2010 0653/21/M/J/10 For Examiner's Use (d) Fig. 9.4 shows a metal nut on the bicycle wheel which is difficult to unscrew. Fig. 9.4 Explain why a long spanner is better than a short spanner to unscrew the nut. [2]

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24 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2010 0653/21/M/J/10 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2010 question paper for the guidance of teachers 0653 COMBINED SCIENCE 0653/21 Paper 21 (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, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2010 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 21 © UCLES 2010 1 (a) community ; population ; ecosystem ; [3] (b) all five organisms included and no others ; arrows between them going the right way ; all links present and correct (allow one missing arrow, or heron / pike feeding on only one species) ; pond weed water snails water voles heron pike [3] (c) no food (for primary consumers) ; no oxygen ; [2] (d) (i) C ; B ; E ; [3] (ii) no cell wall / no part A ; no chloroplasts / no part B ; no (large) vacuole / no part F ; not rectangular ; [max 2] [Total: 13] 2 (a) Geiger counter / Geiger (Müller) tube / scintillation counter / spark chamber / cloud chamber / photographic film ; [1] (b) burns ; eye damage / cataracts ; cancer ; mutation (of cells ) / damage to DNA ; radiation sickness ; [max 2]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 21 © UCLES 2010 (c) (i) alpha beta gamma most penetrating
most ionising
;; [2] (ii) alpha ; gamma ; [2] [Total: 7] 3 (a) (i) (good) conductor of electricity / (good) conductor of heat / greater density / lustrous / sonorous / malleable / ductile / high melting point ; [1] (ii) sodium is too reactive / very little strength ; [1] (b) (i) (it is balanced) idea of same number on both sides ; of atoms of each element / numbers stated ; [2] (ii) Fe2O3 ; reduction is loss of oxygen / O removed from Fe2O3 ; [2] (c) (i) ionic/electrovalent ; [1] (ii) solution/compound in liquid form which, conducts electricity / contains free ions ; [1] (iii) electrical ; [1] (iv) any Group 1 or Group 2 metal / zinc ; [1] [allow copper] [Total: 10] 4 (a) (i) brain labelled ; [1] (ii) nerves / nerve cells / neurones ; effectors / muscles / glands ; [2] (b) endocrine ; [1]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 21 © UCLES 2010 (c) (i) P written within area shown ; spinal cord P [1] (ii) insulin ; [1] (iii) liver / muscles ; [1] (iv) ref. to respiration ; no energy (for cells) ; other correct, e.g. hypoglycaemic shock ; [max 2] [Total: 9] 5 (a) vibration of (water) particles / discussion of compressions and rarefactions ; [1] (b) (i) solid ; [1] (ii) (distance =) speed × time ; = 1500 × 0.5 = 750 (m) ; [2] (c) (i) measuring cylinder / graduated beaker ; [1] (ii) balance / scales ; [1] (iii) mass / volume ; [1] [Total: 7]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 21 © UCLES 2010 6 (a) (i) Y ; [1] (ii) X – bromine Y – iodine / astatine Z – fluorine / chlorine (all correct = 2 marks, two or one correct = 1 mark) ;; [2] (b) (i) all correct for 1 protons, neutrons, electrons ; [1] (ii) 10 ; [1] (iii) only protons and neutrons have mass / electrons have no mass ; [1] (c) chlorine solution kills bacteria ; may help to prevent disease / other acceptable benefit ; removes stains more easily / reference to bleaching ; [max 2] [Total: 8] 7 (a) 36 ; [1] (b) warm air less dense than cold ; warm air near the ground (in open field) rises ; warm air cannot get out of the glasshouses ; [max 2] (c) too hot (in glasshouse A) ; ref. to pollination (by bees); less pollination in glasshouse A ; so fewer tomatoes produced ; [max 2] (d) carbon dioxide (concentration) ; wind ; water supply / humidity; pests / pesticides / animals ; weeds ; soil / availability of minerals ; light ; [max 2] [Total: 7]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0653 21 © UCLES 2010 8 (a) (i) 22 – 20 % ; 78 – 80 % ; [2] (ii) carbon dioxide / water vapour / any noble gas ; [1] (b) (i) SO2 ; [1] (ii) leads to acid rain ; which may damage buildings / harm aquatic ecosystems / organisms ; breathing the gas may cause respiratory distress / detail ; [max 2] (c) (i) covalent ; [1] (ii) O = C = O 2 × O bonded to central C ; by double bonds ; [2] (so 2 × C bonded to central O by double bonds scores 1 mark) [Total: 9] 9 (a) (i) B – C ; [1] (ii) 5 s ; [1] (allow 4.8 – 5) (b) (i) (work done =) force × distance ; = 250 × 10 = 2500 J ; [2] (ii) kinetic / movement ; heat / sound ; [2] (c) (i) series ; [1] (ii) 8 (ohms) ; [1] (d) larger (turning force) / moment ; [2] because distance is larger/moment = F × d ; [Total: 10]