Cambridge IGCSE Science - Combined 0653 — 2016 Oct/Nov Paper 3 · Variant 2

This document consists of 20 printed pages. DC (ST/FD) 123042/3 © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 9 3 3 2 8 4 7 5 7 0 * COMBINED SCIENCE 0653/32 Paper 3 (Extended) October/November 2016 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 an HB 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 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.

2 0653/32/O/N/16 © UCLES 2016 1 Fig. 1.1 shows a wireless doorbell to alert people inside a building that someone has come to visit. bell unit bell push inside the house outside the house ding dong Fig. 1.1 When the button in the bell push is pressed, a radio signal is sent to the bell unit, and the bell sounds. (a) Table 1.1 shows part of the electromagnetic spectrum. Table 1.1 X-rays ultraviolet infra-red highest frequency lowest frequency (i) Three forms of electromagnetic radiation are shown in Table 1.1. State which of these forms of electromagnetic radiation has the shortest wavelength. Give a reason for your answer. Electromagnetic radiation having the shortest wavelength is … Reason … …[1] (ii) In Table 1.1, write the name of the electromagnetic waves used for radio signals in the correct position in the electromagnetic spectrum. [1]

3 0653/32/O/N/16 © UCLES 2016 [Turn over (b) The radio signal travels at a speed of 3 × 108 m / s. (i) Suggest the speed of visible light. Give a reason for your answer. … …[1] (ii) The radio signal has a frequency of 200 MHz (200 × 106 Hz). Calculate the wavelength of the radio signal. State the formula that you use and show your working. formula working wavelength = …m [2]

4 0653/32/O/N/16 © UCLES 2016 (c) The bell unit also contains an electrical circuit. Fig. 1.2 shows two different bells, A and B, inside the bell unit. When the wireless signal is received, an arm moves and hits the two bells. bell A bell B arm Fig. 1.2 (i) Complete the sequence of useful energy transfers when someone hears the bells. from … energy to … energy to … energy. [2] (ii) Bell A emits a loud sound of frequency 500 Hz. Bell B emits a quieter sound of frequency 250 Hz. State which bell, A or B, produces the sound with the 1. higher pitch, … 2. larger amplitude. … [1] (d) The sound of the bell is transmitted through the air as a succession of compressions and rarefactions. Describe how the arrangement of molecules in the air in a compression is different from the arrangement in a rarefaction. … …[1] electrical

5 0653/32/O/N/16 © UCLES 2016 [Turn over 2 The Periodic Table lists all of the elements in order. (a) State, in terms of atomic structure, which number determines the order of the elements in the Periodic Table. …[1] (b) Part of the Periodic Table is shown in Fig. 2.1. The letters in this table are not the symbols of the elements. B C D A H I II VII VI V IV III VIII E F G Fig. 2.1 (i) Choose from letters A to H to complete the sentences below. Each letter may be used once, more than once or not at all. The most reactive element in Group I is … . The least reactive element in Group VII is … . The three elements with the same number of outer shell electrons are … , … and … . [3] (ii) Suggest two properties of the element labelled G. 1. … 2. … [2] (c) Aluminium, Al, is in Group III. Oxygen, O, is in Group VI. Deduce the charges on the aluminium ion and on the oxygen ion. aluminium ion charge … oxygen ion charge … [2]

6 0653/32/O/N/16 © UCLES 2016 (d) Magnesium ions have the formula Mg2+. Nitride ions have the formula N3–. Deduce the formula of magnesium nitride. …[1]

7 0653/32/O/N/16 © UCLES 2016 [Turn over 3 (a) Fig. 3.1 shows a plant cell as seen under the microscope. Draw lines to label the parts of the plant cell that carry out the functions shown. controlling centre of the cell controls what enters and leaves the cell where respiration takes place Fig. 3.1 [3] (b) (i) With reference to Fig. 3.1 describe how the contents of the cell enable it to carry out photosynthesis. … … … … …[2] (ii) Write the balanced symbol equation for photosynthesis. …[2]

8 0653/32/O/N/16 © UCLES 2016 4 Fig. 4.1 shows an electric iron for smoothing clothes. An electric heater inside the iron is connected to the mains electricity supply. mains electricity cable Fig. 4.1 (a) The heating element inside the electric iron is made of two long thin wires that have equal resistance. The two wires • are made of the same material, • are equal in diameter. (i) State another property that must be the same for the wires to have equal resistance. …[1] (ii) The wires are connected in parallel with each other, and connected to the mains a.c. power supply through a fuse and a switch. Draw a circuit diagram for this arrangement. Use the resistor symbol to represent each of the wires. [4]

9 0653/32/O/N/16 © UCLES 2016 [Turn over (b) In an electric steam iron, the element heats water inside the iron. When the water boils, the steam comes out through holes in the bottom of the iron. Explain, in terms of the distances between water molecules, why the steam is forced out from the holes in the bottom of the iron. … … … …[2] (c) Fig. 4.2a and Fig. 4.2b show another switch included inside the iron to control the temperature. This type of switch uses a bimetallic strip, made of two different metals, brass and steel, joined together. Fig. 4.2a shows the switch when the iron is cold. Fig. 4.2b shows the switch when the iron has reached the correct temperature for ironing. brass steel on cold to a.c. power supply to heater Fig. 4.2a brass steel off hot to a.c. power supply to heater Fig. 4.2b Explain why this bimetallic strip switches off the heating element when the temperature increases. … … … …[2]

10 0653/32/O/N/16 © UCLES 2016 5 A student investigates the speed of the reaction between excess dilute hydrochloric acid and powdered calcium carbonate. The equation for the reaction is shown below. 2HCl(aq) + CaCO3(s) CaCl2(aq) + H2O(l) + CO2(g) Fig. 5.1 shows some of the apparatus she uses. conical flask powdered calcium carbonate hydrochloric acid digital balance Fig. 5.1 (a) Name one other piece of apparatus that is needed to investigate the speed of this reaction. …[1] (b) The student plots the mass of the conical flask and its contents, as shown in Fig. 5.2. mass / g time / s 0 0 Fig. 5.2 (i) Explain why the mass decreases, … … the mass becomes constant. … … [2]

11 0653/32/O/N/16 © UCLES 2016 [Turn over (ii) On Fig. 5.2, draw a line to show the results obtained when the experiment is repeated at a higher temperature. [2] (iii) State and explain, in terms of particle collisions, the effect of increasing the concentration of the acid on the speed of the reaction. effect … explanation … … …[2] (c) The student repeats the experiment using excess powdered calcium carbonate. Suggest two further processes that are used to obtain calcium chloride crystals from the mixture formed in this reaction. first process … second process … [2] (d) Pure calcium chloride is an ionic substance that can be melted and electrolysed. Predict the substances that form at the electrodes during this electrolysis. at the anode … at the cathode … [2]

12 0653/32/O/N/16 © UCLES 2016 6 (a) Fig. 6.1 is a diagram of an alveolus in the lungs. wall of capillary plasma red blood cell alveolus oxygen Fig. 6.1 (i) An arrow in Fig. 6.1 shows the diffusion of oxygen. Draw another arrow to show the diffusion of carbon dioxide. [1] (ii) Describe two ways in which the structure of the alveolus is adapted for efficient gas exchange. 1. … … 2. … … [2] (b) A student uses a machine to measure the volume of air breathed in and out of his lungs. The machine produces a graph showing the results. Fig. 6.2 shows how the volume of his lungs changes as he breathes in and out while resting. 2.0 0 5 time / s 10 2.5 3.0 volume of lungs / dm3 3.5 4.0 Fig. 6.2

13 0653/32/O/N/16 © UCLES 2016 [Turn over (i) State the volume of air he breathes in with each breath. volume = … dm3 [1] (ii) Calculate the total volume that he breathes in during ten seconds. Show your working. total volume = … dm3 [1] (c) The student then does a running exercise. His breathing pattern changes. Fig. 6.3 shows the graph of his breathing while exercising. 0 2.0 1.5 2.5 3.0 3.5 volume of lungs / dm3 5 time / s 10 Fig. 6.3 (i) Describe two ways in which the student’s breathing changes when he starts to exercise. 1. … 2. … [2] (ii) Explain in detail why the student’s breathing needs to change during exercise. … … … … … …[3]

14 0653/32/O/N/16 © UCLES 2016 7 A boy uses a catapult to launch a ball vertically upwards, as shown in Fig. 7.1. Fig. 7.1 The boy places a ball of mass 0.055 kg in the catapult. He applies a force to stretch the elastic cords before the ball is launched. This is shown in Fig. 7.2. When the elastic cords are fully stretched, the boy holds the ball at rest in the catapult. no force applied by boy stretching force applied by boy elastic cords (fully stretched) Fig. 7.2 (a) Explain why, before the boy stretches the catapult, there is a small force stretching the elastic cords. … … …[2]

15 0653/32/O/N/16 © UCLES 2016 [Turn over (b) (i) Describe how the forces in the elastic cords change as the cords stretch. … …[1] (ii) When the cords are fully stretched by a total force of 100 N, the boy holds the ball without moving the catapult. State the total upward force when the elastic cords are fully stretched. Give a reason for your answer. total upward force = … N reason … …[2] (c) The boy releases the stretched catapult and launches the ball. The ball, mass 0.055 kg, moves vertically upwards at a speed of 20 m / s. (i) Calculate the kinetic energy of the ball as it leaves the catapult. State the formula that you use and show your working. formula working kinetic energy = … J [2] (ii) Use your answer to (c)(i) to calculate the maximum height above the catapult reached by the ball. Assume there is no loss of energy to the air as the ball rises. State any formula that you use and show your working. (gravitational field strength g = 10 N / kg) formula working height = …m [2]

16 0653/32/O/N/16 © UCLES 2016 8 (a) Some fuels are listed below. coal natural gas petroleum wood State which of these four fuels is not a fossil fuel. …[1] (b) Petroleum is a mixture of hydrocarbons. It is separated by fractional distillation, as shown in Fig. 8.1. Another process, X, is also shown. petroleum fractional distillation column fraction A fraction B strong heat process X Fig. 8.1 (i) A hydrocarbon in fraction A has a different boiling point from a hydrocarbon in fraction B. Explain why these hydrocarbons have different boiling points. Use ideas about molecules in your answer. … … … … …[2]

17 0653/32/O/N/16 © UCLES 2016 [Turn over (ii) One of the fractions obtained contains octane. Fig. 8.2 shows a molecule of octane. octane key carbon atom hydrogen atom Fig. 8.2 State the formula of octane. … [1] (iii) Process X converts large hydrocarbon molecules into many shorter molecules. Name process X. …[1] (iv) The structure of propene is shown in Fig. 8.3. C H H H H C C H H Fig. 8.3 Describe a chemical test that distinguishes propene from octane. Give the results for both compounds. test … propene result … octane result … [2]

18 0653/32/O/N/16 © UCLES 2016 9 Fig. 9.1 shows a food web in a lake. algae water fleas tadpoles microscopic animals aquatic insects small fish turtles large fish Fig. 9.1 (a) Use the words or phrases in the list below to complete the following sentences. Each word or phrase can be used once, more than once, or not at all. algae consumer decomposers environment food chain nests Sun turtle water flea The source of energy for this food web is the … . The lake is the ecosystem because it contains all the organisms interacting with their … . In this food web one example of a herbivore is a … and one example of a carnivore is a … . [4]

19 0653/32/O/N/16 © UCLES 2016 (b) A food web is a network of interconnected food chains. Use this idea to explain why the small fish in the food web in Fig. 9.1 cannot be placed in just one trophic level. Include two different food chains from Fig. 9.1 in your answer. … … … …[3] (c) The actions of humans can affect the environment. A farmer uses fertiliser near to the lake. Explain what could happen if some of the fertiliser gets washed into the lake. … … … … …[2] 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. 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.

20 0653/32/O/N/16 © UCLES 2016 Group The Periodic Table of Elements 1 H hydrogen 1 2 He helium 4 I II III IV V VI VII VIII 3 Li lithium 7 4 Be beryllium 9 atomic number atomic symbol Key name relative atomic mass 11 Na sodium 23 12 Mg magnesium 24 19 K potassium 39 20 Ca calcium 40 37 Rb rubidium 85 38 Sr strontium 88 55 Cs caesium 133 56 Ba barium 137 87 Fr francium – 88 Ra radium – 5 B boron 11 13 Al aluminium 27 31 Ga gallium 70 49 In indium 115 81 Tl thallium 204 6 C carbon 12 14 Si silicon 28 32 Ge germanium 73 50 Sn tin 119 82 Pb lead 207 22 Ti titanium 48 40 Zr zirconium 91 72 Hf hafnium 178 104 Rf rutherfordium – 23 V vanadium 51 41 Nb niobium 93 73 Ta tantalum 181 105 Db dubnium – 24 Cr chromium 52 42 Mo molybdenum 96 74 W tungsten 184 106 Sg seaborgium – 25 Mn manganese 55 43 Tc technetium – 75 Re rhenium 186 107 Bh bohrium – 26 Fe iron 56 44 Ru ruthenium 101 76 Os osmium 190 108 Hs hassium – 27 Co cobalt 59 45 Rh rhodium 103 77 Ir iridium 192 109 Mt meitnerium – 28 Ni nickel 59 46 Pd palladium 106 78 Pt platinum 195 110 Ds darmstadtium – 29 Cu copper 64 47 Ag silver 108 79 Au gold 197 111 Rg roentgenium – 30 Zn zinc 65 48 Cd cadmium 112 80 Hg mercury 201 112 Cn copernicium – 114 Fl flerovium – 116 Lv livermorium – 7 N nitrogen 14 15 P phosphorus 31 33 As arsenic 75 51 Sb antimony 122 83 Bi bismuth 209 8 O oxygen 16 16 S sulfur 32 34 Se selenium 79 52 Te tellurium 128 84 Po polonium – 9 F fluorine 19 17 Cl chlorine 35.5 35 Br bromine 80 53 I iodine 127 85 At astatine – 10 Ne neon 20 18 Ar argon 40 36 Kr krypton 84 54 Xe xenon 131 86 Rn radon – 21 Sc scandium 45 39 Y yttrium 89 57–71 lanthanoids 89–103 actinoids 57 La lanthanum 139 89 Ac lanthanoids actinoids The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.) actinium – 58 Ce cerium 140 90 Th thorium 232 59 Pr praseodymium 141 91 Pa protactinium 231 60 Nd neodymium 144 92 U uranium 238 61 Pm promethium – 93 Np neptunium – 62 Sm samarium 150 94 Pu plutonium – 63 Eu europium 152 95 Am americium – 64 Gd gadolinium 157 96 Cm curium – 65 Tb terbium 159 97 Bk berkelium – 66 Dy dysprosium 163 98 Cf californium – 67 Ho holmium 165 99 Es einsteinium – 68 Er erbium 167 100 Fm fermium – 69 Tm thulium 169 101 Md mendelevium – 70 Yb ytterbium 173 102 No nobelium – 71 Lu lutetium 175 103 Lr lawrencium –

® IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 6 printed pages. © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education COMBINED SCIENCE 0653/32 Paper 3 Extended Theory October/November 2016 MARK SCHEME Maximum Mark: 80 Published 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 2016 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 2016 0653 32 © UCLES 2016 1 (a) (i) X-rays (no mark) reference to highest frequency / v = fλ / as f increases, λ decreases ; [1] (ii) X- rays ultra- violet infra- red radio waves radio (waves) in correct box ; [1] (b) (i) 3 × 108 m/s because all e/m waves travel at same speed ; [1] (ii) v = fλ ; λ = 3 × 108 / 200 x 106 = 1.5 (m) ; [2] (c) (i) kinetic ; sound ; [2] (ii) (higher pitch) A and (larger amplitude) A ; [1] (d) closer together in compression / further apart in rarefaction ; [1] 2 (a) atomic / proton (number) ; [1] (b) (i) F ; H ; B, E, F (any order) ; [3] (ii) high density ; high melting point ; coloured compounds ; (act as) catalysts ; (also allow any general metal property) [max 2] (c) 3+ / Al3+ ; 2– / O2- ; [2] (d) Mg3N2 ; [1]

3 4 Page 3 3 (a) from the the the (b) (i) (ii) 4 (a) (i) (ii) (b) dist refe (c) met bra so b Ca m the top, la nucleus ; cell memb cytoplasm contains c which con which trap and turn li 6CO2 + 6 formulae ; balancing length ; a.c. supply (any 2 cor resistors i supply, sw tance betwe erence to in tals expand ass expands bends and ambridge I abel lines g rane ; ; chloroplasts ntain chlorop p sunlight / a ght energy 6H2O Æ C6 ; ; y, fuse, res rrect, 1 mar n parallel ; witch, fuse a een molecu ncrease in (s d on heating s more than breaks con Mark Sc GCSE – Oc © oing to s ; phyll ; absorb light into chemic 6H12O6 + 6 istor, switch k; all 4 corr all in series, ules in gas g steam) pres g ; n steel ; tact ; cheme ctober/Nov © UCLES 201 energy ; cal energy ; 6O2 h symbols ;; rect 2 marks , fuse contro greater than ssure / press vember 201 16 ; ; s) olling both p n in liquid ; sure forces 6 parallel bran steam out ; Syllabus 0653 nches ; ; s Paper 32 [3 [max 2 [2 [ [4 [2 [max 2 3] 2] 2] 1] 4] 2] 2]

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 32 © UCLES 2016 5 (a) stopwatch / timer ; [1] (b) (i) CO2 / gas produced / lost from the reaction ; CaCO3 used up / no CaCO3 left ; [2] (ii) steeper initial line starting at same point ; levels off at same mass ; [2] (iii) increases ; more effective / successful collisions between particles / particles collide more often / more chance of collisions ; [max1] if no reference to both particles and collisions [2] (c) (1st) filtration ; (2nd) evaporation / heating / crystallisation ; [2] (d) (1st) chlorine and calcium identified ; (2nd) at correct electrodes ; [2] 6 (a) (i) arrow drawn going from plasma into alveolus ; [1] (ii) thin wall ; good blood supply / many capillaries ; large surface area (of alveolus) ; moist surface ; [max 2] (b) (i) 0.6 dm3 ; [1] (ii) (0.6 × 3 =) 1.8 (dm3) ; [1] (c) (i) became faster ; became deeper / owtte ; [2] (ii) to get more oxygen (to the cells) ; for respiration ; to release energy / for muscle contraction ; to remove carbon dioxide more quickly ; [max 3]

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 32 © UCLES 2016 7 (a) weight of ball (+ cords) ; effect of Earth’s gravitational field (accept gravity) on mass of ball etc ; (allow both marks if second point is made without first) [2] (b) (i) (total) upward force increases in proportion to / with extension / in accordance with Hooke’s Law ; [1] (ii) 100 (N) ; when cords are fully stretched, no further movement / change in length / forces balanced ; [2] (c) (i) (KE =) ½ mv2 / ½ × 0.055 × (20)2 ; = 11 (J) ; [2] (ii) PE gained = KE lost = mgh / h = 11 ÷ (0.055 × 10) ; = 20 (m) ; [2] 8 (a) wood ; [1] (b) (i) reference to difference in molecular size ; reference to difference in intermolecular forces (of attraction) ; [2] (ii) C8H18 ; [1] (iii) cracking ; [1] (iv) test bromine / bromine water ; propene result decolourises and octane result no change ; [2]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 32 © UCLES 2016 9 (a) Sun ; environment ; water flea ; turtle ; [4] (b) two food chains correctly written (at least as far as the small fish) showing small fish in different trophic levels ;; ref. to small fish at level 3 or 4 in the chosen food chains ; [3] (c) eutrophication ; reference to increased algal / surface plant growth ; restricted light ; failure of photosynthesis (in underwater plants) ; death / decomposition of underwater plants ; removal of oxygen from water (by respiring decomposers) ; death / suffocation of underwater animals ; [max 2]