Cambridge IGCSE Science - Combined 0653 — 2017 May/June Paper 4 · Variant 2

* 2 7 6 3 9 5 2 4 4 9 * This document consists of 20 printed pages. DC (NF/SW) 137783/2 © UCLES 2017 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education COMBINED SCIENCE 0653/42 Paper 4 (Extended) May/June 2017 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 0653/42/M/J/17 © UCLES 2017 1 (a) Use lines to connect the box on the left to different boxes on the right to make correct sentences. One is done for you. The sentence reads ‘Enzymes are present in all organisms’. Draw three more lines to make three more correct sentences. are used up during reactions. are biological catalysts. are present in all organisms. are needed for diffusion to take place. are denatured by low temperatures. work best in a narrow pH range. are made from amino acids. Enzymes [3] (b) Microorganisms are used in the production of yoghurt. If the temperature increases the rate of yoghurt production also increases until 46 °C is reached. As the temperature increases further, the rate of yoghurt production rapidly decreases. A student thinks that enzymes in the microorganisms are involved in making yoghurt. Suggest whether the student is correct. Explain your answer. … … … … … [2]

3 0653/42/M/J/17 © UCLES 2017 [Turn over (c) Fig. 1.1 shows a small section of a starch molecule. Starch is a very large molecule, made up from many basic units which are joined together. basic unit part of a starch molecule Fig. 1.1 (i) Name the basic unit shown in Fig. 1.1. … [1] (ii) Name another large molecule, found in some living organisms, which could be made up from the same basic unit as shown in Fig. 1.1. … [1] (iii) Name the element found in a protein molecule which is absent from a starch molecule. … [1]

4 0653/42/M/J/17 © UCLES 2017 2 (a) A teacher places the first three metals of Group I in the Periodic Table into separate beakers of water. This is shown in Fig. 2.1. beaker A beaker B beaker C water Fig. 2.1 The three pieces of metal are the same size. A student records her observations in Table 2.1. Table 2.1 beaker the metal floats the metal melts time for metal to fully react in seconds flames are seen A yes yes 15 yes B yes no 60 no C yes yes 40 no (i) Use the information in Table 2.1 to identify the three metals in beakers A, B and C. beaker A … beaker B … beaker C … [2] (ii) Complete the sentences about the reaction in beaker A using suitable words or phrases. The temperature in the beaker increases because this is an … reaction. During this reaction … energy is changed into … and … energy. [3]

5 0653/42/M/J/17 © UCLES 2017 [Turn over (iii) The fourth metal in Group I is rubidium, Rb. The student observes the reaction between a piece of rubidium and water. The piece of rubidium is the same size as the other metals. Suggest how long it takes for the piece of rubidium to react completely. … seconds [1] (b) Suggest why Group I metals must not be added to dilute hydrochloric acid. … … [1] (c) Saucepans are usually made from an iron alloy rather than from pure iron. Some coins are made from a copper alloy rather than from pure copper. Explain why these alloys are used instead of the pure metals. (i) iron alloy for saucepans … … [1] (ii) copper alloy for coins … … [1]

6 0653/42/M/J/17 © UCLES 2017 3 (a) Fig. 3.1 shows an aircraft flying at a constant height and constant speed above the Earth’s surface. The arrows labelled A, B, C and D show the forces acting on the aircraft. C A B D Fig. 3.1 (i) State which letter, A, B, C or D, corresponds to: 1. frictional force, … 2. lifting force. … [1] (ii) Force D is measured and found to be 500 000 N. State whether force B is 500 000 N or has a different value. Give a reason for your answer. … … [1] (iii) During the flight, the aircraft burns 1000 kg of fuel. State the effect this has on force D. Explain why this happens. effect on force D … explanation … … [1]

7 0653/42/M/J/17 © UCLES 2017 [Turn over (b) The speed of the aircraft increases steadily in 30 s from 100 m / s to 160 m / s. (i) Calculate the acceleration of the aircraft. Show your working and state the unit of your answer. acceleration = … unit … [2] (ii) As the speed increases, the aircraft loses height from 10 000 m to 8000 m. The aircraft has a mass of 50 000 kg. Calculate the loss in gravitational potential energy of the aircraft. State the formula you use and show your working. (g = 10 N / kg) formula working potential energy lost = … J [2]

8 0653/42/M/J/17 © UCLES 2017 4 (a) Fig. 4.1 shows a diagram of the internal structure of the heart. A left ventricle B aorta pulmonary artery Fig. 4.1 (i) The ventricles contract to send blood out of the heart. State what happens to the valves at A and B when the ventricles contract. A … B … [1] (ii) There is a difference in pressure of the blood travelling in the aorta compared with the blood travelling in the pulmonary artery. Explain why it is important for blood to have different pressures in these arteries. … … … … [2] (b) (i) The heart muscle must be supplied with blood. Explain how coronary heart disease affects the blood supply to the heart muscle. … … … [2]

9 0653/42/M/J/17 © UCLES 2017 [Turn over (ii) State one way in which sufferers of coronary heart disease can improve their lifestyle. … [1] (c) The hormone adrenaline is secreted into the blood by the adrenal glands which are above the kidneys. One of the effects of adrenaline is to increase the heart rate. (i) Describe one situation when the rate of adrenaline secretion increases rapidly. … … [1] (ii) State how the hormone adrenaline is removed from the blood. … … [1] (d) Hormones can affect the direction of growth in plants. Fig. 4.2 shows what happens when a plant has bright light coming from one side. light light at start after a few days Fig. 4.2 Explain how hormones in the plant caused the phototropic response shown in Fig. 4.2. … … … … … [3]

10 0653/42/M/J/17 © UCLES 2017 5 Petroleum is a mixture of hydrocarbons. (a) (i) Name the process that is used to separate liquids with different boiling points. … [1] (ii) Describe the relationship between the size of hydrocarbon molecules and the size of intermolecular attractive forces. … … … [1] (iii) Describe the relationship between the size of the intermolecular attractive forces between hydrocarbon molecules and the boiling points of the hydrocarbons. … … … [1] (b) The structures of two hydrocarbon molecules, D and E, are shown in Fig. 5.1. H H C H H C H H C H H D H H C H H C H H C E Fig. 5.1 (i) Name the types of hydrocarbon shown by molecules D and E. D … E … [2]

11 0653/42/M/J/17 © UCLES 2017 [Turn over (ii) Describe a chemical test used to distinguish between D and E. State the observation for each. test … observation with D … … observation with E … … [2] (iii) Molecule E is made by heating larger hydrocarbon molecules in the presence of a catalyst. Name this process. … [1] (c) Heptane, C7H16, undergoes complete combustion in the presence of excess oxygen. Complete the equation for this reaction. C7H16 + …O2 …CO2 + …H2O [2]

12 0653/42/M/J/17 © UCLES 2017 6 An aircraft is flying at a height of 10 000 m. Outside the aircraft the temperature is −55 °C, but inside the aircraft the air temperature is kept at 21 °C. (a) (i) State the main method of thermal energy transfer from air inside the aircraft to the air outside. … [1] (ii) Describe in terms of molecular motion how thermal energy is lost from air inside the aircraft to the air outside. … … … … [2] (b) Inside the aircraft’s jet engines, the temperature reaches 1700 °C as the jet fuel burns. The combustion of the fuel forms exhaust gases containing carbon dioxide and water molecules. (i) State which of the diagrams in Fig. 6.1, X, Y or Z, shows the arrangement of these molecules as they are formed in the engine. Give a reason for your answer. X Y Z Fig. 6.1 diagram … reason … … [1] (ii) Suggest how the motion of the water molecules formed in the jet engines differs from the motion of water molecules in a glass of water inside the aircraft. Give a reason for your answer. … … … [2]

13 0653/42/M/J/17 © UCLES 2017 [Turn over (c) Radar is a method of tracking aircraft from the ground using electromagnetic waves. A radar signal is transmitted from the ground to an aircraft several kilometres away. The signal is then reflected by the aircraft back to the ground. (i) The reflected signal is received back at the transmitting station 0.0002 s after transmission. The speed of radar waves is 3 × 105 km / s. Calculate the distance of the aircraft from the transmitter. Show your working. distance = … km [3] (ii) The radar signal has a frequency of 1.5 × 109 Hz. Table 6.1 shows the range of frequencies across the electromagnetic spectrum. Table 6.1 radiation gamma radiation X-rays ultra- violet visible light infrared micro- waves radio waves approximate frequency range above 1019 Hz 1016 Hz to 1019 Hz 1014 Hz to 1016 Hz 4 × 1014 Hz to 8 × 1014 Hz 1011 Hz to 1014 Hz 109 Hz to 1011 Hz below 109 Hz Use this data to state whether the radar signal is at the short or long wavelength end of the electromagnetic spectrum. Explain your answer. … … … … [2]

14 0653/42/M/J/17 © UCLES 2017 7 The lake shown in Fig. 7.1 is a balanced ecosystem. The steady flow of nutrients into the lake enables the water plants to grow and provide food for the small animals and fish. light nutrients oxygen water lake air algae and small animals water plants fish Fig. 7.1 (a) Define the term ecosystem. … … … [2] (b) The feeding relationships of the organisms in Fig. 7.1 are as follows. • the small animals feed on algae • the fish feed on the algae, water plants and small animals. Use the information provided to complete the food web which has been started below. algae water plants [2]

15 0653/42/M/J/17 © UCLES 2017 [Turn over (c) The ecosystem becomes unbalanced when fertiliser is accidentally added to the lake. The fertiliser increases the concentration of nutrients in the lake. Fig. 7.2 shows the lake after a few weeks. nutrients oxygen oxygen water lake air algae plants die dead organisms Fig. 7.2 (i) Explain why the water plants beneath the surface die. … … … … [2] (ii) The fish die due to lack of oxygen. However, Fig. 7.2 shows the algae producing oxygen, some of which goes into the lake. Explain what happens to the oxygen in the lake. … … … [2]

16 0653/42/M/J/17 © UCLES 2017 8 (a) An atom of element X is in Group VI of the Periodic Table. (i) State the number of outer-shell electrons in an atom of X. … [1] (ii) State whether element X is a metal or a non-metal. Suggest one physical property of element X. metal or non-metal … physical property … [1] (b) Chlorine, Cl, is in Group VII of the Periodic Table. (i) Complete Fig. 8.1 to show the electronic structure of an atom of chlorine. Use the Periodic Table on page 20. X X Fig. 8.1 [1] (ii) Draw a dot-and-cross diagram to show all of the outer-shell electrons in a molecule of chlorine, Cl2. Cl Cl [1]

17 0653/42/M/J/17 © UCLES 2017 [Turn over (c) Chlorine reacts with sodium to form a compound. (i) State the type of chemical bond in this compound. … [1] (ii) Describe what happens to sodium atoms and to chlorine atoms when they react together to form this compound. Use ideas about electrons in your answer. sodium atoms … chlorine atoms … [2] (d) Noble gases are unreactive. Explain this observation using ideas about the electronic structure of noble gas atoms. … … [1]

18 0653/42/M/J/17 © UCLES 2017 9 Fig. 9.1 shows a simple circuit set up to investigate the electrical properties of a lamp. lamp switch cell ammeter Fig. 9.1 (a) (i) On Fig. 9.2 use the correct circuit symbols to complete the circuit diagram for the circuit shown in Fig. 9.1. Fig. 9.2 [2] (ii) On Fig. 9.2, using the correct circuit symbol, connect a meter into the circuit that can measure the potential difference across the lamp. [2] (b) The cell has a voltage of 1.5 V, and the reading on the ammeter is 0.6 A for the circuit in Fig. 9.1. The lamp is brightly lit and hot to the touch. Show by calculation that the power dissipated in the circuit is less than 1 W. power = … W [1]

19 0653/42/M/J/17 © UCLES 2017 (c) A second identical lamp is added in series with the lamp in the circuit in Fig. 9.1. The reading on the ammeter decreases, and both lamps are now dimly lit and cool to the touch. (i) Explain why adding the second lamp causes the current to decrease. … … … [1] (ii) Explain why less light and thermal energy are emitted by the two bulbs than by one bulb on its own in the circuit. … … … … [2]

20 0653/42/M/J/17 © UCLES 2017 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. 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 a registered trademark. This document consists of 7 printed pages. © UCLES 2017 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education COMBINED SCIENCE 0653/42 Paper 4 Extended Theory May/June 2017 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 May/June 2017 series for most Cambridge IGCSE®, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components.

0653/42 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 2 of 7 Question Answer Marks 1(a) three lines from ‘Enzymes’ to are biological catalysts ; work best in a narrow pH range ; are made from amino acids ; 3 1(b) (correct) 46 °C is optimum temperature / rate decreases above and below 46 °C ; correct reference to denaturation ; 2 1(c)(i) glucose / sugar / simple sugar ; 1 1(c)(ii) glycogen ; 1 1(c)(iii) nitrogen ; 1 Question Answer Marks 2(a)(i) A potassium / K B lithium / Li C sodium / Na 1 or 2 correct, 1 mark all 3 correct, 2 marks 2 2(a)(ii) exothermic ; chemical (potential) ; two from thermal (allow heat) / light / sound / kinetic ; 3 2(a)(iii) in the range 1 to 14 (seconds) inclusive ; 1 2(b) (too) dangerous / (risk of) explosion ; 1 2(c)(i) resists corrosion / does not rust ; 1 2(c)(ii) stronger / more difficult to damage ; 1

0653/42 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 3 of 7 Question Answer Marks 3(a)(i) C B 1 3(a)(ii) (D is 500 000 N) the idea that height remains constant / forces (B and D) are balanced / equal and opposite / the resultant force in the vertical direction is zero ; 1 3(a)(iii) (decreases) the weight decreases ; 1 3(b)(i) acceleration = increase in speed ÷ time / (160 – 100) ÷ 30 ; = 2 m / s2 ; 2 3(b)(ii) potential energy change = mgh or mg∆h / 50 000 × 10 × 2000 ; = 1 × 109 (J) ; 2

0653/42 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 4 of 7 Question Answer Marks 4(a)(i) valve A closes and valve B opens ; 1 4(a)(ii) high(er) pressure required to send blood around the body / travel a long distance / ora ; high(er) pressure in aorta and low(er) pressure in pulmonary artery ; low pressure in pulmonary artery prevents damaging capillaries in lungs ; Max 2 4(b)(i) reduces blood flow in coronary artery / arteries ; by presence of cholesterol / fatty deposits / plaque ; 2 4(b)(ii) less fatty diet / reduced stress / reduced smoking / more exercise ; 1 4(c)(i) any valid fight or flight situation described ; 1 4(c)(ii) destroyed by the liver ; 1 4(d) reference to auxins ; greater concentration on dark side (of stem) ; cause greater (cell) elongation /growth (on that side) ; 3 Question Answer Marks 5(a)(i) fractional distillation ; 1 5(a)(ii) larger molecules / hydrocarbons have larger inter-molecular forces / ora ; 1 5(a)(iii) larger inter-molecular forces means higher boiling point / ora ; 1 5(b)(i) (D) alkane / saturated ; (E) alkene / unsaturated ; 2 5(b)(ii) bromine (water / solution) ; (D) no change and (E) decolourises ; 2 5(b)(iii) cracking ; 1 5(c) (C7H16) + «11«(O2) Î «7«(CO2) + «8«(H2O) ;; 2

0653/42 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 5 of 7 Question Answer Marks 6(a)(i) conduction ; 1 6(a)(ii) (kinetic) energy of air molecules inside transferred to molecules in aircraft wall (fuselage) ; (kinetic) energy transferred between molecules in aircraft wall (fuselage) ; (kinetic) energy transferred from aircraft wall (fuselage) to air molecules outside ; the idea that energy is transferred via vibrating/colliding molecules/particles ; Max 2 6(b)(i) (Z) molecules shown not touching / apart ; 1 6(b)(ii) molecules in jet engine moving faster ; because they are at a higher temperature / have greater kinetic energy ; or molecules in water moving more slowly ; because they are at a lower temperature / have smaller kinetic energy ; or the idea that molecules from the jet exhaust are able to move more freely ; because they are separated / far apart ; or the idea that molecules in water have more restricted movement ; because molecules are close together / touching ; 2 6(c)(i) total distance = speed × time / 3 × 105 × 0.0002 ; = 60 (km) ; so distance aircraft to transmitter = ½ × 60 / 30 (km) ; 3 6(c)(ii) (long wavelength end) it is in the microwave part of spectrum / it is a microwave / it is at the low frequency end ; lower frequency waves have longer wavelength / ref. to inverse proportionality / reference to the formula ν = f × λ ; 2

0653/42 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 6 of 7 Question Answer Marks 7(a) an area where the organisms interact with each other ; and (interact with) their environment ; 2 7(b) all organisms written only once ; feeding relationships shown using arrows ; 2 7(c)(i) no light ; for photosynthesis ; 2 7(c)(ii) bacteria take in / use the oxygen ; for their respiration ; 2 Question Answer Marks 8(a)(i) 6 ; 1 8(a)(ii) non-metal together with one from electrical / thermal insulator / low melting / boiling point ovp ; 1 8(b)(i) (2), 8, 7 ; 1 8(b)(ii) one shared pair and six non-bonding electrons on each Cl ; 1 8(c)(i) ionic ; 1 8(c)(ii) sodium loses one (electron) ; chlorine gains one (electron) ; 2

0653/42 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 7 of 7 Question Answer Marks 8(d) reference to full outer shell ; 1 Question Answer Marks 9(a)(i) correct symbols for ammeter and lamp ; only the shown components connected in series ; 2 9(a)(ii) voltmeter connected in parallel with lamp ; correct symbol for voltmeter ; 2 9(b) P = V × I = 1.5 × 0.6 = 0.9 (W) ; 1 9(c)(i) total resistance more, (so current decreases / so dimmer lamps) ; 1 9(c)(ii) the idea that (compared to one bulb) the (total) potential difference (across two bulbs) is the same but the current is lower (V the same I lower) ; (if V is the same, but I is less) then less power (dissipated) / less total energy transformed per unit time ; or the relation P = V × I / E = V × I × t therefore shows that the power / energy per unit time is lower (when two bulbs are used) ; 2