Cambridge IGCSE Science - Combined 0653 — 2005 May/June Paper 3 · Variant 1

Centre Number Candidate Number Name UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/03 Paper 3 May/June 2005 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 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. 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 20. For Examiner’s Use 1 2 3 4 5 6 7 8 9 Total This document consists of 20 printed pages. IB05 06_0653_03/2RP  UCLES 2005 [Turn over 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. www.XtremePapers.com

2 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 1 (a) Fig. 1.1 shows the structure of a wind-pollinated flower. P Fig. 1.1 Explain one way in which the structure of this flower increases the chance of successful pollination. [2] (b) Fig. 1.2 shows the structure of a cell that is found inside the plant’s leaves. Q Fig. 1.2 (i) Suggest one way in which the structure of this cell differs from a cell in the part labelled P in Fig. 1.1. Explain the reason for your suggestion. [2]

3 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (ii) Describe the function of the part labelled Q in Fig. 1.2. [2] (c) The leaf cell shown in Fig. 1.2 requires a steady supply of water. (i) Name the tissue in which water is transported from the roots to the leaves. [1] (ii) Describe how water is lost from leaf cells, and how this water leaves the leaf and enters the air around it. [3]

4 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 2 Fig 2.1 shows what is observed when a piece of potassium reacts in a container of chlorine. chlorine flames potassium clouds of potassium chloride particles Fig. 2.1 (a) (i) Write the word equation for the reaction. [1] (ii) State which observation in Fig. 2.1 shows that the reaction is exothermic. [1] (b) Potassium chloride can also be made by reacting potassium hydroxide solution with dilute hydrochloric acid. Write a balanced symbolic equation for this reaction. [2]

5 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (c) The apparatus shown in Fig. 2.2 can be used to separate potassium chloride into its elements. + _ A heat molten potassium chloride Fig. 2.2 (i) Explain why potassium ions move towards the cathode. [2] (ii) Describe how potassium ions change into potassium atoms at the cathode. [2]

6 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 3 (a) An elephant can communicate with other elephants using infra-sound. This is a very low frequency vibration, which is usually impossible for a human to hear. (i) Suggest a possible frequency for this vibration. [1] (ii) Explain what is happening when these vibrations travel through the air. You may use a diagram to help you to answer this question. [2] (b) A spider climbs vertically upwards along a thread. (i) The spider weighs 0.02N. Calculate the work done when it climbs 21 cm up the thread. Show your working and state the formula that you use. formula used working [2]

7 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (ii) Calculate the power generated by the spider as it climbs up the thread. It climbs 21 cm in 7 seconds. Show your working and state the formula that you use. formula used working [2] (iii) The mass of the spider is 2g. It begins to move up the thread with an acceleration of 2cm / s2. Calculate the resultant force causing this acceleration. Show your working and state the formula that you use. formula used working [3] (c) A polar bear is a large white furry mammal that lives on the Arctic ice. Suggest and explain one way in which the polar bear is adapted to reduce heat loss in this cold climate. [2]

8 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 4 In the 1950s, many people in London used coal to heat their houses. In early December 1952, the weather was foggy. The sulphur dioxide released from the burning of the coal stayed trapped in the fog. (a) Fig. 4.1 shows the concentration of sulphur dioxide in the air, and also the number of people who died, from December 1st to December 15th. 1000 800 600 400 200 0 1000 800 600 400 200 0 1st 3rd 5th 7th 9th 11th 13th 15th deaths per day sulphur dioxide / parts per million date in December Fig. 4.1 (i) How many more people died on December 8th than on December 1st? [1] (ii) Explain how the information in the graph in Fig. 4.1 supports the idea that sulphur dioxide is harmful to health. [1] (iii) Suggest why the numbers of deaths were still high on December 15th, even though the concentration of sulphur dioxide had returned to a low level. [1]

9 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (b) Explain how the emission of sulphur dioxide into the atmosphere can lead to the formation of acid rain. [2] (c) The combustion of coal also releases soot particles into the atmosphere. Some of these may fall onto plant leaves, forming a coating over them and blocking their stomata. Explain how this could reduce the rate of growth of the plants. [2]

10 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 5 (a) The full chemical symbols of four elements are shown below. H 1 1 O 16 8 Mg 24 12 Ar 40 18 Use this information to answer (i) to (iii) below. (i) Name the element which does not react with any of the others, and explain your answer. name explanation [1] (ii) Name a pair of elements which combine together to form an ionic compound. and [1] (iii) Name two elements whose atoms have electrons in three energy levels (shells) and [1] (b) Magnesium reacts with oxygen to form magnesium oxide. 2Mg + O2 2MgO A student found that when 4.8g of magnesium were completely oxidised, 8.0g of magnesium oxide were formed. (i) Calculate the mass of oxygen which combined with 4.8g of magnesium. [1] (ii) The student then burned 2.4g of magnesium in a vessel containing 5.0g of oxygen. Calculate the mass of oxygen left over after all the magnesium had reacted. Show your working. [2] (c) A student investigated factors affecting the rate of reaction between magnesium and dilute hydrochloric acid. She wanted to investigate the effects of changing • the surface area of the magnesium, • the temperature of the hydrochloric acid. The apparatus she used is shown in Fig. 5.1.

11 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use gas syringe hydrochloric acid magnesium water bath Fig. 5.1 Results of four of her experiments are shown in Table 5.1. In each experiment she used 2.0g of magnesium and 20.0 cm3 of hydrochloric acid. Table 5.1 experiment temperature of acid / oC volume of gas collected / cm3 time taken to collect gas /minutes rate of reaction / cm3 per minute 1 18 50 2 25 2 18 65 2 32.5 3 28 100 2 4 41 105 1 (i) Name the gas given off in this reaction. [1] (ii) State one other important factor (variable) which the student must keep the same in each experiment. [1] (iii) Complete the two remaining boxes in Table 5.1. [1] (iv) Suggest which pair of experiments the student carried out in order to observe the effect on reaction rate of changing the surface area of the magnesium. Explain your answer briefly. [2]

12 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 6 (a) Fig. 6.1 shows a fish tank containing one fish. Fig. 6.1 If observed from the corner, there appear to be two fish in the tank. Fig. 6.2 shows the tank from above. Fig. 6.2 (i) Two rays of light have been drawn from the fish. Continue the rays of light in Fig. 6.2 to show how the light waves reach the eye. [1] (ii) Use the diagram to explain why the observer can see two fish. You may wish to add to Fig. 6.2 to help you answer this question. [2]

13 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (b) An electric heater is designed to heat the fish tank. The circuit containing this heater is shown in Fig. 6.3. heater Fig. 6.3 The current flowing through the heater is 0.5 A and the voltage across it is 5.0 V. Calculate the resistance of the heater. Show your working and state the formula that you use. formula used working [2] (c) The electric heater is placed at the bottom of the fish tank rather than at the top. Explain why this is more effective for heating the water in the tank. [2]

14 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 7 Fig. 7.1 shows the structure of the human alimentary canal. A B stomach small intestine appendix colon anus caecum Fig. 7.1 (a) Name the parts labelled A and B. A B [2]

15 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (b) The boxes below contain the name of a nutrient, a part of the alimentary canal in which it is digested, and the name of the molecules which are formed during digestion. Draw lines to connect the nutrient to the appropriate part of the alimentary canal and to the molecules which are formed. Two lines have been drawn for you. mouth one part of alimentary canal where it is digested small intestine stomach fat type of nutrient protein starch amino acids smaller molecules formed by digestion fatty acids and glycerol glucose [2] (c) Fig. 7.1 shows that the small intestine is the longest part of the alimentary canal. Suggest how this helps it to carry out its functions effectively. [2] (d) Glucose is a good energy food. Athletes often drink liquids containing glucose to provide them with energy quickly. (i) Describe how glucose provides energy for an athlete’s muscles. [2] (ii) Describe how you can test a drink to find out if it contains a reducing sugar, such as glucose. [2]

16 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 8 (a) When it has been buried, compressed and heated underground for millions of years, wood is converted into a common type of solid fuel. Name the solid fuel formed from wood over millions of years. [1] (b) Fig. 8.1 shows an experiment carried out on some small pieces of wood. methane gas heat water (this dissolves substances from the wood) wood pieces Fig. 8.1 The wood in the experiment does not catch fire. Suggest the type of chemical reaction that is occurring. Explain your answer briefly. type of reaction explanation [2] (c) Propane, C3H8, is a gaseous hydrocarbon fuel. (i) When propane is shaken with bromine solution, the mixture remains orange. Explain what this observation shows about the bonding in propane molecules. [2]

17 © UCLES 2005 0653/03/M/J/05 [Turn over For Examiner's Use (ii) The equation below shows the complete combustion of propane. Complete the balancing of the equation. [1] C3H8 + … O2 3CO2 + … H2O (iii) Calculate the formula mass of propane. Show your working. [2]

18 © UCLES 2005 0653/03/M/J/05 For Examiner's Use 9 (a) Fig. 9.1 shows a toy bird suspended from a ceiling by a spring. A Fig. 9.1 (i) The upward force of the spring has been labelled A. Draw another arrow on the diagram to show the direction of the other force acting on the bird. Label it B. [1] (ii) The bird is not moving. What can be stated about the sizes and directions of forces A and B? [1] (b) The toy bird is made of a thin piece of aluminium. On Fig. 9.1 write the letter C where the centre of mass is likely to be. [1]

19 Every reasonable effort has been made to trace all copyright holders where the publishers (i.e. UCLES) are aware that third-party material has been reproduced. The publishers would be pleased to hear from anyone whose rights they have unwittingly infringed. University of Cambridge International Examinations is part of the University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2005 0653/03/M/J/05 For Examiner's Use (c) The mass of the toy bird is 7.5 g and its volume is 3.0 cm3. (i) Suggest how you could measure the volume of the bird. [2] (ii) Calculate the density of the bird. Show your working and state the formula that you use. formula used working [2]

20 © UCLES 2005 0653/03/M/J/05 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 June 2005 question paper 0653 COMBINED SCIENCE 0653/03 Paper 3 (Extended Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and students, to indicate the requirements of the examination. It shows the basis on which Examiners were initially instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began. Any substantial changes to the mark scheme that arose from these discussions will be recorded in the published Report on the Examination. 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 discussion or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the June 2005 question papers for most IGCSE and GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Grade thresholds for Syllabus 0653 (Combined Science) in the June 2005 examination. minimum mark required for grade: maximum mark available A C E F Component 3 80 54 30 20 16 The threshold (minimum mark) for B is set halfway between those for Grades A and C. The threshold (minimum mark) for D is set halfway between those for Grades C and E. The threshold (minimum mark) for G is set as many marks below the F threshold as the E threshold is above it. Grade A* does not exist at the level of an individual component.

June 2005 IGCSE MARK SCHEME MAXIMUM MARK: 80 SYLLABUS/COMPONENT: 0653/03 COMBINED SCIENCE Paper 3 (Extended Theory)

Page 1 Mark Scheme Syllabus Paper IGCSE – JUNE 2005 0653 3 © University of Cambridge International Examinations 2005 1 (a) stamens/anthers, dangling/outside flower; wind can catch pollen; or stigma, dangling/outside flower; can catch pollen from air; or stigma feathery; can catch more pollen; max [2] (b) (i) this cell has chloroplasts/P does not have chloroplasts; this cell photosynthesises/P does not photosynthesise; [2] (ii) contains, chromosomes/genes/DNA; (which contain) inherited information; controls activities of cell; ref. to protein synthesis ; max [2] (c) (i) xylem; [1] (ii) out of cell by osmosis; evaporation (from cell wall); diffusion; as water vapour; through stomata; max [3] 2 (a) (i) potassium + chlorine = potassium chloride; [1] (ii) flames; [1] (b) KOH + HCl → KCl + H2O; [2] (c) (i) potassium ions are positive; and are attracted to the negative (cathode); [2] (ii) gain electrons; one electron each; ions discharged; max [2] 3 (a) (i) 20 Hz or lower; [1] (ii) vibration passes from one particle to the next; compressions and rarefactions; longitudinal waves/description; max [2] (b) (i) work = force x distance; 0.02 x 21/100 = 0.0042 J; [2] (ii) power = work/time; 0.0042/7 = 0.0006 W; [2] (iii) force = mass x acceleration; 0.002 x 0.02; 0.00004 N; [3]

Page 2 Mark Scheme Syllabus Paper IGCSE – JUNE 2005 0653 3 © University of Cambridge International Examinations 2005 (c) white fur; poor emitter of radiation; fur traps air; good insulator; much fat; good insulator; max [2] 4 (a) (i) 650 [1] (ii) as sulphur dioxide goes up, deaths go up; [1] (iii) idea of delay between exposure and death; [1] (b) dissolves in water; forms sulphuric acid/sulphurous acid; [2] (c) prevents/reduces, entry of carbon dioxide/absorption of light; so less photosynthesis; [2] 5 (a) (i) argon, is noble gas/inert gas/full outer shell; [1] (ii) magnesium and, oxygen/hydrogen; [1] (iii) magnesium and argon; [1] (b) (i) 3.2 g; [1] (ii) 4.8 g magnesium reacts with 3.2 g oxygen, so 2.4 g reacts with 1.6 g; 5.0 - 1.6 = 3.4 g; [2] (c) (i) hydrogen; [1] (ii) concentration of acid; [1] (iii) 50 and 105; [1] (iv) 1 and 2; temperature/all other variables, were kept constant; [2] 6 (a) (i) straight lines bending at interface and reaching eye ; [1] (ii) lines extended backwards; light appears to travel in straight lines; [2] (b) resistance = voltage/current; 10 ohms; [2] (c) convection; hot water rises/cold water sinks; hot water less dense/cold water more dense; max [2] 7 (a) A oesophagus; B rectum; [2]

Page 3 Mark Scheme Syllabus Paper IGCSE – JUNE 2005 0653 3 © University of Cambridge International Examinations 2005 (b) line from mouth to starch and starch to glucose; line from small intestine to fat and protein to amino acids; [2] (c) function is digestion/absorption; more time for these to take place; larger surface area for absorption; max [2] (d) (i) respiration; glucose and oxygen; changed to carbon dioxide and water; ref. to ATP; [2] (ii) add Benedict’s and heat; yellow/red, colour if present; [2] 8 (a) coal; [1] (b) (thermal) decomposition; small molecules being formed from larger ones; [2] (c) (i) propane has only single bonds/no double bonds; between carbon atoms; if double bonds present bromine decolourises; max [2] (ii) C3H8 + 5O2 → 3CO2 + 4H2O; [1] (iii) (12 x 3) + (8 x 1); 44; [2] 9 (a) (i) arrow points downwards; [1] (ii) forces are equal and opposite; [1] (b) C in suitable position; [1] (c) (i) use measured volume of water; submerge toy and calculate change in level/volume of water displaced; [2] (ii) density = mass/volume; 7.5/3.0 = 2.5 g/cm3; [2]