Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2016 Oct/Nov Paper 3 · Variant 1

This document consists of 32 printed pages. DC (CW/FD) 119529/8 © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 0 0 9 9 1 2 5 0 4 2 * CO-ORDINATED SCIENCES 0654/31 Paper 3 (Extended) October/November 2016 2 hours 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 32. 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 0654/31/O/N/16 © UCLES 2016 1 Scientists can estimate the concentration of carbon dioxide in the Earth’s atmosphere in past centuries. They drill into the thick ice near the poles to remove samples of ice that contain trapped air. The ice is thousands of years old, with the oldest ice at the deepest levels. They sample at different levels and measure the concentration of carbon dioxide in the trapped air. (a) Table 1.1 shows some results. Table 1.1 year carbon dioxide concentration / % 1000 0.0280 1200 0.0275 1400 0.0280 1600 0.0270 1800 0.0280 2000 0.0345 (i) In the year 2000, the carbon dioxide concentration in the trapped air was 0.0345%. State the two gases that make up most of the rest of the atmosphere. 1 … 2 … [2] (ii) Using the information in Table 1.1, describe how the carbon dioxide concentration in the Earth’s atmosphere changed between the year 1000 and the year 2000. … … … …[3] (b) Name a biological process that (i) releases carbon dioxide into the atmosphere, …[1] (ii) removes carbon dioxide from the atmosphere. …[1]

3 0654/31/O/N/16 © UCLES 2016 [Turn over (c) Suggest two reasons why the carbon dioxide concentration in the Earth’s atmosphere changed between 1800 and 2000 as shown in Table 1.1. 1 … 2 … [2] (d) A scientist suggested that, when air gets trapped in the ice, its carbon dioxide concentration might change. Suggest what measurements could be taken to check whether this happens. … … …[2] (e) Explain how an increase in carbon dioxide concentration in the Earth’s atmosphere could cause global warming. … … … …[2]

4 0654/31/O/N/16 © UCLES 2016 2 Five test-tubes containing different substances are labelled A, B, C, D and E as shown in Fig. 2.1. Dilute sulfuric acid is added to each of the five substances. barium nitrate solution A B C D E dilute sulfuric acid dilute sulfuric acid copper copper carbonate magnesium sodium hydroxide solution dilute sulfuric acid dilute sulfuric acid dilute sulfuric acid Fig. 2.1 (a) (i) Suggest the letter of the test-tube containing a substance that releases a gaseous element when the dilute sulfuric acid is added. Name the gaseous element. test-tube … gaseous element …[1] (ii) Suggest the letter of the test-tube containing a substance that releases a gaseous compound when the dilute sulfuric acid is added. Name the gaseous compound. test-tube … gaseous compound …[1] (iii) Suggest the letter of the test-tube containing a substance in which there is no chemical change. Explain your answer in terms of the reactivity series. test-tube … explanation … …[1]

5 0654/31/O/N/16 © UCLES 2016 [Turn over (iv) Dilute sulfuric acid contains sulfate ions. Suggest the letter of the test-tube containing a substance that produces a white precipitate. State the name of the precipitate. test-tube … white precipitate …[1] (b) Sulfuric acid is made industrially in the Contact process. Vanadium oxide acts as a catalyst in this process. (i) The chemical symbol for vanadium is shown. 51 23V State • the number of neutrons in the nucleus of this atom, … • the number of electrons in a vanadium atom. … [2] (ii) State the name of the collection of metals in the Periodic Table to which vanadium belongs. …[1]

6 0654/31/O/N/16 © UCLES 2016 (iii) Fig. 2.2 shows part of the Contact process. Boxes X and Y contain diagrams that represent the molecules involved in an oxidation reaction catalysed by vanadium oxide. X Y key Z vanadium oxide catalyst reaction vessel atom of sulfur atom of oxygen Fig. 2.2 In box Z in Fig. 2.2, draw one molecule to represent the product of the oxidation reaction. Use the key to draw the atoms of the molecule. [1] (iv) Write a balanced chemical equation for the oxidation reaction that occurs in the reaction vessel to produce the product in box Z. …[2]

7 0654/31/O/N/16 © UCLES 2016 [Turn over 3 (a) Three identical kettles have each been filled with the same volume of water at 25 °C. Fig. 3.1 shows the three kettles a few minutes later. A B C heating element Fig. 3.1 Kettle A contains water that remains at 25 °C. Kettle B contains water that is just starting to boil at 100 °C. Kettle C contains water that has been boiling for a few minutes but is still at 100 °C. (i) Explain why the water volume in kettle B is now different to that in kettle C. … …[1] (ii) Explain why energy is required to boil the water in kettle C even though the temperature remains at 100 °C. … … …[1] (iii) Describe two differences between evaporation and boiling. 1 … … 2 … … [2]

8 0654/31/O/N/16 © UCLES 2016 (iv) When the water boils, some becomes water vapour in the air. Fig. 3.2 shows the arrangement of particles in a gas, liquid and solid. A B C Fig. 3.2 State and explain which diagram, A, B or C, best represents: water at 25 °C, … explanation … … water vapour. … explanation … … [2] (b) Explain why the electric kettles shown in Fig. 3.1 have the heating element at the bottom of the kettle. … … …[2]

9 0654/31/O/N/16 © UCLES 2016 [Turn over (c) A kettle rated at 2000 W is connected to a 250 V supply. Show that the current in the heating element is 8 A. State the formula you use and show your working. formula working [2]

10 0654/31/O/N/16 © UCLES 2016 4 A gardener increases the number of trees by taking cuttings. The gardener cuts off part of a stem (the cutting) and places it in water, as shown in Fig. 4.1. cutting removed cutting placed in water water Fig. 4.1 The cutting develops roots as shown in Fig. 4.2. The gardener then plants the cutting in the ground. developing roots cutting water Fig. 4.2 (a) Name the type of cell division by which the roots are produced. … [1]

11 0654/31/O/N/16 © UCLES 2016 [Turn over (b) Suggest how the cutting will compare to the parent tree in (i) its genotype, … …[1] (ii) its overall appearance once it is fully grown. … …[1] (c) Before the roots develop on a cutting, the gardener encloses the cutting in a plastic bag, as shown in Fig. 4.3. string cutting plastic bag Fig. 4.3 Suggest why the gardener places the plastic bag over the cutting before the roots develop. … … …[2]

12 0654/31/O/N/16 © UCLES 2016 (d) As the cutting grows, it needs nitrate ions and magnesium ions for healthy growth. Describe the effect on the cutting of (i) a deficiency of nitrate ions, … …[1] (ii) a deficiency of magnesium ions. … …[1]

13 0654/31/O/N/16 © UCLES 2016 [Turn over 5 A student studies the relative reactivity of four metals. She adds small pieces of different metals to solutions of metal salts. The metals and solutions she uses, together with her results, are shown in Table 5.1. Table 5.1 zinc sulfate solution copper sulfate solution silver nitrate solution metal M salt solution zinc 3 3 3 copper 7 3 7 silver 7 7 7 metal M 7 3 3 key 3 shows that a metal displacement reaction occurs 7 shows that a reaction does not occur (a) (i) Zinc reacts with copper sulfate solution because zinc is more reactive than copper. Describe and explain one change of colour which is observed when zinc and copper sulfate solution react. observation … … explanation … … [2] (ii) Use the results in Table 5.1 and the Periodic Table to suggest the proton number of metal M from the list. 11 20 26 Explain your answer. proton number of metal M … explanation … … … … [2]

14 0654/31/O/N/16 © UCLES 2016 (b) The reaction between zinc and silver nitrate solution is shown by the balanced ionic equation. Zn(s) + 2Ag+(aq) Zn2+(aq) + 2Ag(s) (i) State the meaning of the state symbol (aq). …[1] (ii) Use the information in the ionic equation to explain why the reaction between zinc atoms and silver ions is an example of a redox reaction. … … … …[2] (c) In another experiment, shown in Fig. 5.1, the student adds magnesium ribbon to excess copper sulfate solution. She measures the temperature of the solution for ten minutes. thermometer insulated beaker copper sulfate solution magnesium ribbon lid Fig. 5.1

15 0654/31/O/N/16 © UCLES 2016 [Turn over Fig. 5.2 shows a graph of her results. 0 1 2 3 4 5 time / minutes temperature 6 7 8 9 10 Fig. 5.2 Complete the sentences below using suitable words. During the first three minutes of the experiment the temperature rises. The speed of the particles in the solution … . The temperature rises because the reaction is … and … energy is transferred into thermal energy. [3]

16 0654/31/O/N/16 © UCLES 2016 6 Fig. 6.1 shows a train. Fig. 6.1 The train starts from rest and accelerates with constant acceleration. The train reaches 45 m / s after 60 seconds. The train then continues at this constant speed for 150 seconds. (a) (i) On the grid below sketch a speed / time graph for the train. 0 0 20 40 60 80 10 30 50 70 50 100 time / s speed m / s 150 200 250 [2] (ii) Describe how you could calculate the distance travelled by the train from the speed / time graph. … …[1]

17 0654/31/O/N/16 © UCLES 2016 [Turn over (b) The train has a mass of 6.0 × 105 kg. Calculate the kinetic energy of the train 120 seconds after the train starts from rest. State the formula you use and show your working. formula working kinetic energy = … J [3] (c) During one part of the journey the train accelerates at 0.75 m / s2. Calculate the force required to cause this acceleration. State the formula you use and show your working. formula working force = … N [2]

18 0654/31/O/N/16 © UCLES 2016 7 (a) Use the terms in the list to complete the sentences about homeostasis. Each term may be used once, more than once, or not at all. against away from concentration environment negative positive temperature towards within Homeostasis is defined as the maintenance of a constant internal … . Homeostasis depends on … feedback, where a change … a set point causes a change … the set point. [3] (b) Fig. 7.1 shows how the glucose concentration of a person’s blood changes over a period of three hours during the middle of the day. 11:00 3 4 5 blood glucose concentration in mMol / litre 6 7 12:00 13:00 time of day / hours 14:00 Fig. 7.1 (i) State the time at which the person’s blood glucose concentration is highest. … [1] (ii) Suggest why the person’s blood glucose concentration rises immediately after the first hour. …[1]

19 0654/31/O/N/16 © UCLES 2016 [Turn over (iii) Suggest two processes in the cells of the body that may cause the glucose concentration to decrease. 1 … 2 … [2] (c) Describe the role of the liver in the control of the glucose concentration in blood. … … … … …[3]

20 0654/31/O/N/16 © UCLES 2016 8 (a) Fig. 8.1 represents the electron arrangement in an atom of sulfur. key electron nucleus Fig. 8.1 (i) State the charge of the ion that forms from a sulfur atom. Explain this charge in terms of the number of protons and the number of electrons. charge … explanation … … … [3] (ii) Zinc is extracted from rocks containing zinc sulfide, ZnS. Use this formula and your answer to (a)(i) to predict and explain the charge of an ion of zinc. charge … explanation … … … [2]

21 0654/31/O/N/16 © UCLES 2016 [Turn over (b) Zinc is produced by the electrolysis of a concentrated solution of zinc sulfate. Fig. 8.2 shows the apparatus used to produce zinc by this method. d.c. power supply positive electrode negative electrode electrolyte containing zinc sulfate Fig. 8.2 During electrolysis, the cathode becomes covered by a layer of zinc atoms. Describe why zinc atoms form on the cathode. … … …[2] (c) A layer of zinc on the surface of a steel object prevents the object from rusting. (i) State the word that is used to describe steel that is protected from rusting by a layer of zinc. … [1] (ii) Explain why a layer of zinc will continue to protect steel from rusting even when the zinc layer is damaged to expose the steel. … … …[2]

22 0654/31/O/N/16 © UCLES 2016 (d) Brass is an alloy of zinc and copper. Many types of brass are less malleable than zinc or copper. State the meaning of the term malleable. … …[1]

23 0654/31/O/N/16 © UCLES 2016 [Turn over 9 (a) A nuclear power station uses the energy from nuclear fission to generate electricity. Plutonium-239 can be used in nuclear fission. (i) Describe the difference between nuclear fission and nuclear fusion. … … …[1] (ii) Plutonium-239, 239 94 Pu, decays by alpha (α) emission to produce an isotope of uranium. Use the correct nuclide notation to write a symbol equation for this decay process. 239 94 Pu … + … [3] (b) The voltage in a power station is increased using a transformer before transmitting electrical power. (i) Explain the benefit of transmitting electrical power at a high voltage. … … …[1]

24 0654/31/O/N/16 © UCLES 2016 (ii) Fig. 9.1 shows a simple transformer. core primary coil secondary coil Fig. 9.1 The transformer increases the voltage from 25 000 V to 600 000 V. The number of turns in the primary coil is 5000. Calculate the number of turns in the secondary coil. State the formula you use and show your working. formula working number of turns = … [3]

25 0654/31/O/N/16 © UCLES 2016 [Turn over (c) An overhead power cable transmits electrical power from the power station to a town 10 km away. The resistance of the cable is 6.5 Ω. (i) Predict the resistance of a cable which has twice the cross-sectional area. resistance = … Ω [2] (ii) State one way of changing the resistance of the cable, other than changing its cross-sectional area. …[1] (iii) Apart from the increased cost, suggest and explain one negative effect of doubling the cross-sectional area of the cable. … … …[2]

26 0654/31/O/N/16 © UCLES 2016 10 (a) Fig. 10.1 shows a fetus developing in the uterus. Z X Y fetus Fig. 10.1 (i) Name the parts labelled X, Y and Z. X … Y … Z … [3] (ii) State the function of part Y. … …[1] (iii) Describe how the blood flowing away from the fetus in part Z differs in composition from that flowing towards the fetus. … … … …[3]

27 0654/31/O/N/16 © UCLES 2016 [Turn over (b) After a baby is born, the mother can feed her baby by breast-feeding or by bottle-feeding. (i) Describe two benefits of breast-feeding. 1 … … 2 … … [2] (ii) Describe one benefit of bottle-feeding. … …[1]

28 0654/31/O/N/16 © UCLES 2016 11 Fig. 11.1 shows apparatus used to investigate the compounds produced when ethanol burns. ethanol burner cobalt chloride paper cold water U-tube limewater pump draws combustion products through the apparatus Fig. 11.1 (a) Before the ethanol burner is lit, the cobalt chloride paper is blue and the limewater is colourless. Predict and explain the changes in appearance of the cobalt chloride paper and the limewater shortly after the burner is lit. cobalt chloride paper … explanation … limewater … explanation … [4] (b) Name two substances that react together in an addition reaction to produce ethanol. 1 … 2 … [1]

29 0654/31/O/N/16 © UCLES 2016 [Turn over (c) The formula of ethanol is C2H6O. (i) Show that the relative molecular mass of ethanol is 46. [1] (ii) Calculate the mass of ethanol contained in 250 cm3 of an aqueous solution that has a concentration of 0.5 mol / dm3. Show your working and give the unit. mass of ethanol = … unit = … [3]

30 0654/31/O/N/16 © UCLES 2016 12 (a) A star emits γ-rays and visible light. γ-rays and visible light are parts of the electromagnetic spectrum. (i) Place γ-rays and visible light in their correct positions in the incomplete electromagnetic spectrum shown in Fig. 12.1. [1] X-rays infra-red waves microwaves Fig. 12.1 (ii) State why it takes the same time for γ-rays and visible light to travel from the star to the Earth. … … …[1] (iii) The γ-rays are more dangerous than visible light to an observer on a space station. Explain why. … …[1] (b) Below are four terms used to describe a wave. Draw a line from each term to its definition. term definition amplitude how far the wave travels in one second frequency the distance from any point on one wave to the same point on the next wave speed the distance from the centre of a wave to the top or to the bottom of the wave wavelength the number of waves passing a fixed point in one second [2]

31 0654/31/O/N/16 © UCLES 2016 (c) Telescopes used to observe stars contain mirrors. Fig. 12.2 shows two rays of light from an object O striking a mirror. mirror O Fig. 12.2 (i) Draw the reflected rays. [1] (ii) Extend the lines of the reflected rays behind the mirror to show the position of the image. Label the image I. [1] (d) Telescopes also contain lenses. Rays of light from a distant star pass through the lens shown in Fig. 12.3. Fig. 12.3 (i) On Fig. 12.3, use a double-headed arrow ( ) to indicate the focal length of the lens. [1] (ii) As light passes through the lens, the direction of the light is changed. State the name of this process. … [1]

32 0654/31/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 – 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.

® IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 12 printed pages. © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/31 Paper 3 Theory (Extended) October/November 2016 MARK SCHEME Maximum Mark: 120 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 0654 31 © UCLES 2016 Question Answer Marks 1(a)(i) nitrogen ; oxygen ; 2 1(a)(ii) little / no overall change then increases ; some fluctuations ; increases from 1800 ; by 0.0065% ; max 3 1(b)(i) respiration / decomposition / excretion ; 1 1(b)(ii) photosynthesis ; 1 1(c) (increased:) burning of fossil fuels ; deforestation ; industrialisation ; human population / activity ; max 2 1(d) measure content of air at present ; measure sample from most recent ice ; 2 1(e) absorbs radiation / IR / heat / energy ; radiates back to Earth ; 2 Total: 13

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 2(a)(i) D AND hydrogen ; 1 2(a)(ii) C AND carbon dioxide ; 1 2(a)(iii) B AND copper (too) unreactive (to displace hydrogen from dilute acid) / copper less reactive than hydrogen ; 1 2(a)(iv) A AND barium sulfate ; 1 2(b)(i) 28 ; 23 ; 2 2(b)(ii) transition (series /metals) ; 1 2(b)(iii) ; 1 2(b)(iv) 2SO2 + O2 → 2SO3 formulae ; balanced ; 2 Total: 10

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 3(a)(i) some of the water in kettle C has boiled away / evaporated ; 1 3(a)(ii) latent heat (of vaporisation) / (energy required) to separate molecules from each other ; 1 3(a)(iii) evaporation can occur at any temperature / boiling only happens at the boiling point ; evaporation happens only at the surface / boiling happens throughout the liquid ; boiling takes energy in (endothermic) to occur / evaporation lets only the molecules with the highest kinetic energy out ; evaporation can occur using the internal energy of the system / boiling requires an external source of heat ; evaporation produces cooling / boiling does not ; evaporation is a slow process / boiling is a rapid process ; max 2 3(a)(iv) (water is) B AND most particles are touching and random arrangement ; (water vapour is) C AND particles are spread out (and random arrangement) ; 2 3(b) convection ; heated water is less dense / expands ; hot water rises ; max 2 3(c) (I) = P / V ; = 2000 / 250 ( = 8 A) ; 2 Total: 10

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 4(a) mitosis ; 1 4(b)(i) identical ; 1 4(b)(ii) similar ; 1 4(c) retains humid air around the cutting ; reduces water loss / transpiration ; 2 4(d)(i) stunted growth ; 1 4(d)(ii) yellow leaves ; 1 Total: 7 Question Answer Marks 5(a)(i) (zinc) changes from grey to darker grey / brown / pink ; copper forms on the surface ; OR (copper sulfate) changes from blue to less blue / colourless ; copper (ion) is removed / displaced from the solution / owtte ; 2 5(a)(ii) (26) this is iron ; metal M less reactive than zinc but more reactive than copper / silver ; the other metals (are sodium and calcium which) are both more reactive than zinc ; max 2 5(b)(i) aqueous / water solution ; 1

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 5(b)(ii) zinc (atoms) lose electrons and are oxidised ; silver (ions) gain electrons and are reduced ; 2 5(c) increases / gets faster / goes up ; exothermic ; chemical / chemical potential ; 3 Total: 10 Question Answer Marks 6(a)(i) Acceleration line gradient correct ; Constant velocity line correct at 45 m / s for 150 s anywhere ; 2

Page 7 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 6(a)(ii) Area under graph / AVP ; 1 6(b) Speed = 45 m / s ; KE = ½ mv2 / ½ × 6.0 × 105 × 45 × 45 ; 6.1 × 108 (J) ; 3 6(c) Force = mass × acceleration / ma / 6.0 × 105 × 0.75 ; 4.5 × 105 (N) ; 2 Total: 8 Question Answer Marks 7(a) environment ; negative ; (3rd line) away from AND towards ; 3 7(b)(i) 12.30 ; 1 7(b)(ii) Eats a meal ; 1 7(b)(iii) respiration ; glycogen synthesis ; insulin secretion ; max 2 7(c) liver converts glucose to glycogen / glycogen to glucose ; liver stores glycogen ; insulin causes uptake of glucose ; glucagon causes release of glucose ; max 3 Total: 10

Page 8 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 8(a)(i) 2– ; gains 2 electrons to complete outer shell ; more (negative) electrons than (positive) protons ; 3 8(a)(ii) 2+ ; reference to the need for charge balance ; 2 8(b) zinc ions are attracted / move to the cathode ; zinc ions, gain electrons / are discharged, at the cathode ; 2 8(c)(i) galvanised ; 1 8(c)(ii) sacrificial protection / sacrificial barrier ; (if steel exposed) zinc rather than steel corrodes ; because zinc more reactive (than iron) ; max 2 8(d) malleable refers to ability to be shaped (without breaking) ; 1 Total: 11 Question Answer Marks 9(a)(i) fission is splitting of nuclei and fusion is joining of nuclei ; 1 9(a)(ii) Pu 239 94 → U 235 92 + α 4 2 α 4 2 / e 4 2Η ; 92U ; Nucleon number of daughter nuclide: 235 ; 3 9(b)(i) reduces energy / power losses ; 1

Page 9 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 9(b)(ii) Ns = Np × Vs / Vp ; = 5000 × 600 000 / 25 000 ; = 120 000 ; 3 9(c)(i) resistance decreases / any answer in the range 0 < R < 6.5 ; resistance is halved / 3.25 ohms ; 2 9(c)(ii) material / temperature ; 1 9(c)(iii) cable will have greater, mass / weight / heavier ; more force on pylons / need stronger pylons / heavier cables damage pylons ; 2 Total: 13 Question Answer Marks 10(a)(i) X = placenta ; Y = amniotic fluid ; Z = umbilical cord ; 3 10(a)(ii) protection ; 1 10(a)(iii) less oxygen ; less (named) nutrient(s) ; more CO2 ; more urea ; max 3 10(b)(i) antibodies from mother ; mother-baby bonding ; correct balance of nutrients ; no need for sterilising equipment ; max 2

Page 10 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 10(b)(ii) know how much the baby has had ; no need for presence of mother ; less chance of transfer of disease from mother ; max 1 Total: 10 Question Answer Marks 11(a) cobalt chloride paper turns pink ; showing water (vapour) (in the combustion products) ; limewater turns milky ; showing carbon dioxide (in the combustion products) ; 4 11(b) ethene and water / steam ; 1 11(c)(i) (12 × 2) + (1 × 6) + (1 × 16) (= 46) ; 1 11(c)(ii) calculate number of moles in 0.25 dm3: 0.5 ÷ 4 = 0.125 ; calculate mass of ethanol = 46 × 0.125 = 5.75 ; units are g ; 3 Total: 9

Question 12(a)(i) 12(a)(ii) 12(a)(iii) 12(b) Page 11 travel at same s (more) ionising 4 or 3 correct = 2 Camb speed ; ; 2 marks , 2 or 1 Mark bridge IGCSE – correct = 1 mark k Scheme October/Novem © UCLES 2016 Answer k ;; mber 2016 ; Syllabus 0654 s Paper 31 Marks 1 1 1 2

Page 12 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0654 31 © UCLES 2016 Question Answer Marks 12(c)(i) reflected rays correctly drawn ; 1 12(c)(ii) construction lines drawn behind mirror and image correctly located ; 1 12(d)(i) focal length correctly identified ; 1 12(d)(ii) refraction ; 1 Total: 9 I