Cambridge IGCSE Science - Combined 0653 — 2014 Oct/Nov Paper 3 · Variant 3

This document consists of 24 printed pages. DC (SJF/CGW) 89405/3 © UCLES 2014 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 2 6 6 6 9 8 8 3 5 6 * COMBINED SCIENCE 0653/33 Paper 3 (Extended) October/November 2014 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 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 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.

2 0653/33/O/N/14 © UCLES 2014 1 (a) A student performs some experiments to find out what makes iron rust. (i) Fig. 1.1 shows his first experiment. 100 80 60 40 water air cotton wool iron filings 20 Fig. 1.1 Fig. 1.2 shows the apparatus after one week. The iron has rusted and the water has risen up the cylinder. 80 60 40 water air cotton wool iron filings 20 100 Fig. 1.2 Explain why the water has risen up the cylinder. … …[1]

3 0653/33/O/N/14 © UCLES 2014 [Turn over (ii) The student repeats the experiment using helium in the cylinder instead of air. Fig. 1.3 shows the results after one week. 100 80 60 40 water helium cotton wool iron filings 20 Fig. 1.3 The iron has not rusted and the water has not risen up the cylinder. Explain why the water has not risen up the cylinder. … …[1]

4 0653/33/O/N/14 © UCLES 2014 (b) The student writes in his notebook: “When sodium burns in ch lorine it forms ions that are like neon atoms.” (i) State two similarities in the arrangement of electrons in a sodium ion and a neon atom. The Periodic Table on page 24 may help you to answer this question. 1 … … 2 … …[2] (ii) Complete the diagram of the electronic structure of a sodium atom. Na [1] (iii) Describe what happens when a sodium atom becomes a sodium ion. … …[1] (iv) Some sodium chloride is dropped into a container filled with chlorine. Predict whether or not the sodium ions in sodium chloride would react with chlorine atoms. Explain your answer. … …[1]

5 0653/33/O/N/14 © UCLES 2014 [Turn over (c) Name a noble gas. State and explain a use for this noble gas. name … use … explanation … …[2]

6 0653/33/O/N/14 © UCLES 2014 2 (a) Fig. 2.1 shows a man paddling a canoe across a lake. The man is paddling hard to gain speed from rest. R T S U Fig. 2.1 (i) State two forces from R, S, T and U that are equal and opposite. … and … [1] (ii) Explain which force from R, S, T and U is the result of a gravitational field acting on the combined mass of the canoe and man. … …[2] (iii) The canoe moves across the lake from rest to maximum speed with decreasing acceleration, then continues across the lake at a constant speed. Sketch a speed/time graph for this journey. speed time [3]

7 0653/33/O/N/14 © UCLES 2014 [Turn over (b) The man’s energy is transferred to the canoe as it gains speed. The kinetic energy gained by the canoe is less than the energy transferred from the man. The principle of energy conservation applies to these energy transfers. State what happens to the man’s energy that is not transferred into kinetic energy of the canoe. …[1] (c) The man paddles the canoe at a steady speed of 2 m / s. The canoe and man together have a mass of 250 kg. Calculate the kinetic energy of the canoe. State the formula you use and show your working. formula working kinetic energy = … J [2]

8 0653/33/O/N/14 © UCLES 2014 3 (a) Fig. 3.1 shows a diagram of the uterus in a pregnant female. Y Fig. 3.1 (i) Using label lines, label the placenta and cervix on Fig. 3.1. [2] (ii) Complete the sentences using words or phrases from the list. You may use each word or phrase once, more than once or not at all. bacteria carbon dioxide cells glucose viruses The placenta allows dissolved nutrients such as … to pass through to the baby. Other small molecules such as … are also able to pass through the placenta. [2] (iii) Name the liquid found at position Y and state its function. name … function … …[2]

9 0653/33/O/N/14 © UCLES 2014 [Turn over (b) Some of the nutrients that pass through the placenta result from the chemical digestion of large food molecules in the digestive system of the mother. (i) Complete Table 3.1 with ticks (✓) and crosses (✗) to predict whether the digesting enzymes amylase (starch-digesting enzyme) and protease (protein-digesting enzyme) are active in the parts of the digestive system shown. Table 3.1 type of enzyme in the small intestine in the large intestine key ✓ = enzyme active ✗ = enzyme inactive amylase protease [2] (ii) Explain your answers to part (b)(i). … … …[2] (c) The human immunodeficiency virus (HIV) can be transmitted through sexual intercourse. Describe how HIV affects the immune system. … … …[2]

10 0653/33/O/N/14 © UCLES 2014 4 Fig. 4.1 shows an electric hairdryer that uses mains electricity. Fig. 4.1 A heater inside the hairdryer warms the air. A fan blows the warm air out of the hairdryer. (a) The hairdryer contains a switch, a heater to warm the air and an electric motor to drive the fan. The heater and the motor are connected in parallel. Fig. 4.2 shows the circuit symbols for a heater and an electric motor. M electric motor electric heater Fig. 4.2 Complete the circuit diagram for the hairdryer. The circuit has been started for you. mains electricity supply [2] (b) The flow of warm air dries the wet hair by evaporation. Describe in terms of molecules how the flow of warm air speeds up the drying of wet hair. … … … …[3]

11 0653/33/O/N/14 © UCLES 2014 [Turn over (c) If the heated air was not blown out sideways by a fan, it would simply move upwards. Explain why heated air rises. … … …[2] (d) Fig. 4.3 shows information on a label fixed to the hairdryer. 220 V 1100 W Fig. 4.3 (i) State the name of the unit whose symbol is W. …[1] (ii) Use the formula P = IV to show that the current in the hairdryer when in use is 5 A. Show your working. [1]

12 0653/33/O/N/14 © UCLES 2014 (e) The plug on the lead of the hairdryer is fitted with a fuse. One day, the fuse blows while the hairdryer is being used. (i) Give one possible cause for the fuse blowing. … …[1] (ii) The fuse has to be replaced. The current through the hairdryer when in use is 5 A. Several new fuses with different current ratings are available. 2 A 5 A 10 A 15 A Explain which of these four fuses should be used. Fuse … because … … … …[2]

13 0653/33/O/N/14 © UCLES 2014 [Turn over 5 (a) A student investigates the effect of gravity on the growth of a seedling. The student germinates a seed. When the radicle is clearly visible, he pins the seedling to a board, as shown in Fig. 5.1 (a). He positions the board on its side so that the radical is horizontal. The radicle continues to grow and curves downwards, as shown in Fig. 5.1 (b). radicle pin board board Fig. 5.1 (a) Fig. 5.1 (b) (i) Name the growth response shown by the seedling. …[1] (ii) Explain why this growth response is an advantage to the seedling. … … …[2]

14 0653/33/O/N/14 © UCLES 2014 (b) Fig. 5.2 shows a diagram of a radicle similar to the one in Fig. 5.1 (a). The shaded area shows the location of hormones that cause the response in (a)(i). radicle Fig. 5.2 Describe fully how the hormones act to cause the response shown by the radicle. … … …[2] (c) Roots usually get their energy from aerobic respiration. The soil around a seedling becomes waterlogged so there are no air spaces. (i) Suggest how this affects the rate of aerobic respiration. Explain your answer. … …[1] (ii) Predict and explain the effect this will have on the rate of growth of the seedling. … …[1]

15 0653/33/O/N/14 © UCLES 2014 [Turn over Question 6 begins on page 16

16 0653/33/O/N/14 © UCLES 2014 6 Dilute hydrochloric acid reacts with calcium carbonate to produce carbon dioxide gas. (a) Complete the word equation for the reaction. hydrochloric acid + calcium carbonate … + carbon dioxide + … [2] (b) Fig. 6.1 shows the apparatus a student uses to investigate the effect of changing the initial temperature of the acid on the rate of reaction. dilute hydrochloric acid balance calcium carbonate g Fig. 6.1 The student adds the calcium carbonate to excess acid at a temperature of 20 °C. She records the reading of the balance every minute for 7 minutes.

17 0653/33/O/N/14 © UCLES 2014 [Turn over Fig. 6.2 shows the results obtained in the first experiment. 200 202 204 balance reading / g 0 1 2 3 4 time / min 5 6 7 206 208 210 Fig. 6.2 (i) Explain why the mass of the apparatus decreases during the experiment. … …[1] (ii) Describe and explain how the rate of reaction changes during the experiment. … … … …[3]

18 0653/33/O/N/14 © UCLES 2014 (c) The experiment is repeated with the same mass of calcium carbonate and excess acid at a temperature of 30 °C. (i) Use the information from Fig. 6.2 to predict the final mass of the apparatus when the acid has an initial temperature of 30 °C. …[1] (ii) The student finds that the rate of reaction increases as the temperature of the acid increases. Use the idea of particle collision to explain the effect of temperature on the rate of reaction. … … …[2]

19 0653/33/O/N/14 © UCLES 2014 [Turn over 7 Astronomers use telescopes to study the electromagnetic radiation that reaches the Earth from the stars. (a) (i) Complete the sentences below using words or phrases from the list. You may use each term once, more than once or not at all. radio waves sound waves ultra-violet visible light water waves People can see stars with their eyes because the stars emit … . Astronomers need special telescopes to see other types of electromagnetic radiation from stars. Examples of such types of radiation are … and … . [2] (ii) We are able to see the Moon, even though the Moon itself does not emit electromagnetic radiation. State a characteristic behaviour of electromagnetic radiation that enables us to see the Moon. …[1] (b) Some stars emit electromagnetic radiation with a very high frequency, such as X-rays. (i) Fig. 7.1 shows an incomplete diagram of the electromagnetic spectrum. gamma radiation microwaves Fig. 7.1 Mark with an X on Fig. 7.1 the part of the spectrum where X-rays are situated. [1] (ii) A binary consists of two stars close together. In one particular binary, one star emits mainly light, while the other emits mainly X-rays. The light and X-rays leave this binary at the same time. Tick the box next to the correct statement in the list below and give a reason for your answer. X-rays will reach the Earth first. Light will reach the Earth first. X-rays and light will reach the Earth at the same time. reason … … …[2]

20 0653/33/O/N/14 © UCLES 2014 8 (a) Fig. 8.1 shows an experiment to investigate the effect of changing light intensity on the rate of photosynthesis of a water plant called Elodea. lamp metre rule water Elodea Fig. 8.1 The light intensity is altered by changing the distance between the lamp and the plant. The number of bubbles of oxygen produced by the plant per minute is used to find the rate of photosynthesis. The results are shown in Fig. 8.2. 20 0 40 average number of bubbles of oxygen produced by the plant per minute 0 10 20 30 40 distance from lamp to plant / cm 50 60 80 Fig. 8.2 Use Fig. 8.2 to describe how the rate of photosynthesis of the plant changes as the light intensity is varied. … … …[2]

21 0653/33/O/N/14 © UCLES 2014 [Turn over (b) Fig. 8.3 shows some of the living organisms in a pond. plant P plant Q Fig. 8.3 Suggest how the rate of photosynthesis of plant P compares with plant Q. Explain your answer. … … …[2] (c) The pollution of water by fertilisers can cause eutrophication. (i) Some fertiliser is added to a pond. Describe the effect this will have on the plants that live on the surface of the pond. … …[1] (ii) Use your answer to (b)(i) to predict how eutrophication will affect plant Q in Fig. 8.3. … … …[2]

22 0653/33/O/N/14 © UCLES 2014 9 Aluminium is extracted from an ore called bauxite. Bauxite is a mixture of aluminium oxide and other compounds. The element aluminium is extracted from molten aluminium oxide by electrolysis. The element oxygen is also formed during the electrolysis. (a) Using examples taken from the sentences above, explain (i) one difference between an element and a compound, … …[1] (ii) one difference between a compound and a mixture. … …[1] (b) Aluminium oxide consists of Al 3+ ions and O2– ions. Deduce the formula of aluminium oxide. Explain your answer. …[2]

23 0653/33/O/N/14 © UCLES 2014 (c) In industry aluminium is extracted from aluminium oxide by electrolysis. Fig. 9.1 shows the apparatus used. molten mixture containing aluminium oxide molten aluminium carbon cathode lining the electrolysis cell carbon anode + – Fig. 9.1 Explain, in terms of the ions present, how aluminium is formed at one of the electrodes. … … … …[3] (d) Copper can be extracted from an ore containing copper oxide by heating it with carbon. Explain why aluminium cannot be obtained from aluminium oxide in the same way. … … …[2]

24 0653/33/O/N/14 © UCLES 2014 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. 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. Group 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 91 238 231 147 237 244 243 247 247 251 252 257 258 259 260 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 82 209 209 210 222 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 55 226 223 Ra Radium 88 a X b a = relative atomic mass X = atomic symbol b = atomic (proton) number Key DATA SHEET * 58–71 Lanthanoid series † 90–103 Actinoid series The volume of one mole of any gas is 24dm3 at room temperature and pressure (r.t.p.).

® IGCSE is the registered trademark of Cambridge International Examinations. CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International General Certificate of Secondary Education MARK SCHEME for the October/November 2014 series 0653 COMBINED SCIENCE 0653/33 Paper 3 (Extended 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 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 October/November 2014 series for most Cambridge IGCSE®, Cambridge International A and AS Level components and some Cambridge O Level components.

Page 2 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 33 © Cambridge International Examinations 2014 1 (a) (i) iron has reacted with oxygen in the air / water takes the place of oxygen that has reacted with the iron ; [1] (ii) iron has not reacted with helium / helium is unreactive ; [1] (b) (i) same number of electrons ; same number of electron shells ; full electron shells / reference to complete outer shell ; [max 2] (ii) 2,8,1 configuration ; [1] (iii) sodium atom has lost an electron ; [1] (iv) (no reaction) sodium ions have electron configuration with full outer shell / sodium ions do not gain or lose electrons ; [1] (c) name and use of noble gas ; property related to use ; [2] [Total: 9] 2 (a) (i) R, T ; [1] (ii) T ; T is the weight of canoe and man / description of downward force due to gravity / the Earth; [2]

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Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 33 © Cambridge International Examinations 2014 4 (a) complete circuit + switch ; correct parallel connection ; [2] (b) water molecules move faster / has increased kinetic energy as they are heated by warm air / owtte ; attraction forces between more water molecules are broken ; more water molecules have enough energy to escape (from water / hair) / owtte ; air flow removes escaped molecules so cannot return to hair / owtte ; [max 3] (c) air molecules further apart as temperature rises ; (heated) air becomes less dense (than surrounding air), so rises ; [2] (d) (i) watt(s) ; [1] (ii) I = (P/V) = 1100/220 (= 5 A) ; [1] (e) (i) short circuit (accept other reasonable ideas which might lead to fuse melting) ; [1] e.g. too much current flowing in the circuit ; (ii) 10 A (no mark) 2 A and 5 A fuses would blow / 10 A is the smallest fuse which will not flow ; 15 A fuse gives less protection than 10 A ; [2] [Total: 12] 5 (a) (i) geotropism ; [1] (ii) makes sure roots grow downwards / does not matter which way up the seed is planted (the roots will always grow downwards) ; to anchor plant ; absorbs mineral ions / water ; [max 2] (b) auxins / the hormones inhibit slow down growth ; retarded cell elongation where shaded / at bottom of the root ; cells at top grow/expand normally / reference to differential growth ; [max 2]

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 33 © Cambridge International Examinations 2014 (c) (i) no oxygen therefore slows or stops respiration ; [1] (ii) slows growth due to less / no energy being released ; [1] [Total: 7] 6 (a) calcium chloride ; water ; [2] (b) (i) carbon dioxide lost from apparatus ; carbon dioxide gas has mass ; [max 1] (ii) rate decreases ; quickly at first then more slowly / stops at mass 203 g / after 6 minutes ; (because) acid concentration decreases ; (because) surface area of calcium carbonate decreases ; reference to reduced collision frequency ; [max 3] (c) (i) 203 g ; [1] (ii) particles have more (kinetic) energy / move faster at higher temperature ; collide more frequently ; increased chance of successful collision ; [max 2] [Total: 9] 7 (a) (i) visible light ; radio waves (and) ultra-violet (both required for mark) ; [2] (ii) reflection ; [1] (b) (i) gamma radiation X ; microwaves [1] (ii) X-rays and light will reach the Earth at the same time ; all electromagnetic radiation travels at same speed (in vacuo) ; [2] [Total: 6]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 33 © Cambridge International Examinations 2014 8 (a) as the light intensity decreases the rate of photosynthesis decreases / ora ; not a linear / proportional relationship / numbers taken from graph to illustrate relationship ; [2] (b) faster rate with plant P (than plant Q) or vice versa because it gets more light ; water / plants / debris prevent some light from reaching plant Q ; [2] (c) (i) causes surface plants / algae to grow faster ; [1] (ii) reduces light to plant Q ; little or no photosynthesis ; (leading to) reduced growth of plant / plant dies ; [max 2] [Total: 7] 9 (a) (i) aluminium / oxygen is an element because it / an element, consists of one type of atom ; aluminium oxide is a compound because it / a compound contains different atoms / elements bonded together ; [max 1] (ii) bauxite is a mixture because it has a variable composition / can be separated ; aluminium oxide is a compound because it contains a fixed proportion of elements / can only be separated by chemical methods ; [max 1] (b) Al2O3 ; idea of balanced charges ; [2] (c) aluminium ions migrate / move to / go to are attracted to the negative electrode / cathode ; electrons flow from cathode to each aluminium ion ; 3 electrons / aluminium ions are discharged ; [max 3] (d) carbon is less reactive than aluminium / below aluminium in the reactivity series / aluminium is more reactive than carbon / above carbon in the reactivity series / copper is less reactive than carbon ; carbon will not react with / reduce / remove oxygen from aluminium oxide / carbon will not displace aluminium ; [2] [Total: 9]