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

This document consists of 20 printed pages. DC (LEG/SW) 122370/2 © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 1 0 8 5 8 5 6 5 9 8 * COMBINED SCIENCE 0653/23 Paper 2 (Core) 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 0653/23/O/N/16 © UCLES 2016 1 Fig. 1.1 shows a man using a longbow to fire arrows at a target. bowstring longbow arrow Fig. 1.1 (a) The man uses a force to pull the arrow back through several centimetres. (i) State the name of the unit of force. …[1] (ii) Explain why work is done by the man when he pulls the arrow back. … …[1] (b) (i) Complete the sequence of energy transfers from when the man pulls the arrow back, to when he releases the arrow towards the target. from … energy in the man to … energy in the longbow and bowstring to … energy in the flying arrow. [3] (ii) Suggest why the efficiency of the energy transfer between the energy in the longbow and bowstring, and the energy of the flying arrow is not 100%. … …[1] (c) The arrow flies 100 m to a target at an average speed of 180 km / hour. (i) Calculate the average speed of the arrow in metres per second. Show your working average speed = … m / s [1]

3 0653/23/O/N/16 © UCLES 2016 [Turn over (ii) Use your answer to (c)(i) to calculate the time in seconds taken for the arrow to reach the target after release. State the formula you use and show your working. formula working time = … s [2]

4 0653/23/O/N/16 © UCLES 2016 2 The chemical symbol of an atom of magnesium is shown below. 24 12Mg (a) Complete Table 2.1 to show the names and numbers of the two types of particle in the nucleus of this magnesium atom. Table 2.1 particle number [2] (b) A student uses the apparatus in Fig. 2.1 to burn some magnesium in air. heat crucible magnesium Fig. 2.1 A white solid, magnesium oxide, is formed. Write the word equation for this reaction. + [2]

5 0653/23/O/N/16 © UCLES 2016 [Turn over (c) Fig. 2.2 shows test-tubes A and B which both contain dilute sulfuric acid. The student adds some magnesium to test-tube A. He adds some magnesium oxide to test-tube B. magnesium test-tube A test-tube B magnesium oxide dilute sulfuric acid Fig. 2.2 State which of the two test-tubes produces a gas which burns with a squeaky pop. Identify the gas which is produced. test-tube … gas … [1] (d) (i) Sodium, a Group I element, reacts with chlorine, a Group VII element, as shown in the equation below. sodium + chlorine sodium chloride Identify the substance in the word equation which contains ionic bonds. Explain your answer. substance … explanation … … [2] (ii) Sodium also reacts with water, as shown in the word equation below. sodium + water sodium hydroxide + hydrogen Identify a substance in the word equation which contains covalent bonds. Explain your answer. substance … explanation … … [2]

6 0653/23/O/N/16 © UCLES 2016 3 (a) Fig. 3.1 shows a plan of the human circulatory system. capillaries in the lungs B C E A D capillaries in the rest of the body Fig. 3.1 (i) State the letter and name of a vein shown in Fig. 3.1. letter … name …[1] (ii) Name the type of structure within the heart labelled D and describe its function. … … …[2] (iii) Describe how the composition of blood changes as it passes through the capillaries of the lungs. … … …[2]

7 0653/23/O/N/16 © UCLES 2016 [Turn over (b) A student is running. His heart beats more quickly. His muscles need more blood for respiration. (i) State the word equation for respiration. …[1] (ii) The energy released by respiration can be used for contraction of his muscles. State two other uses of the energy released. 1. … 2. … [2] (c) A student measures his pulse rate during the day. He takes a reading while sitting, and also as he does different activities. Some of his readings are shown in Table 3.1. Table 3.1 activity number of beats per minute sitting 68 running 164 Y 90 Suggest an activity for Y. Explain your answer. activity … explanation … …[1]

8 0653/23/O/N/16 © UCLES 2016 4 Fig. 4.1 shows a simple solar heating system to provide hot water for a house. hot water storage tank hot water to tank cold water hot water for the house solar heating panel glass tubes inside the panel cold water from mains supply Fig. 4.1 • Cold water in glass tubes inside the panel is heated by energy from the Sun. • The hot water then flows to the hot water storage tank above. • Cold water from the tank flows back to the panel. • A supply of hot water for the house can be taken from the tank. (a) The Sun emits energy as electromagnetic radiation, some of which is absorbed by the solar panel. On Table 4.1, in the correct box write the name of the main part of the electromagnetic spectrum which heats the solar panel. Table 4.1 gamma radiation radio waves ultraviolet [2]

9 0653/23/O/N/16 © UCLES 2016 [Turn over (b) The solar panel is made of glass tubes through which the water flows. Fig. 4.2 shows how each glass tube is placed inside an outer glass tube. The space between the outer and inner tubes has had all the air pumped out, leaving a vacuum between the tubes. outer tube vacuum inner tube Fig. 4.2 State the method of thermal energy transfer 1. from the outer glass tube across the vacuum to the inner tube which contains the water, … 2. from the hot water in the glass tubes up to the storage tank on top of the panel. … [2] (c) The water in the storage tank reaches a temperature of 60 °C on a sunny day. Suggest how the storage tank is designed to prevent the stored hot water cooling down again at night. … …[1]

10 0653/23/O/N/16 © UCLES 2016 (d) The storage tank is made of metal. Describe the change to the storage tank caused by the increase in temperature. … … …[1] (e) On a cold night in winter, the temperature falls below the melting point of water. Suggest one problem this might cause for this solar heating system on the roof of a house. … …[1] (f) Light from the Sun has to pass through the walls of the glass tubes. On Fig. 4.3 complete the ray diagram to show the path of light from the Sun through the outer glass tube into the vacuum between the tubes. Show the angles of incidence and refraction at the air-to-glass surface. air glass vacuum Fig. 4.3 [3]

11 0653/23/O/N/16 © UCLES 2016 [Turn over 5 Fig. 5.1 shows a bottle labelled copper(II) chloride solution. copper(II) chloride solution Fig. 5.1 (a) A student tests the solution in the bottle to make sure that it contains copper chloride. Complete Table 5.1. State the reagents and give the positive result for the test for each ion. Table 5.1 ion reagent result copper(II) chloride [4]

12 0653/23/O/N/16 © UCLES 2016 (b) Fig. 5.2 shows the electrolysis of the copper chloride solution using inert electrodes. – + low voltage d.c. supply Fig. 5.2 (i) Use the words anode, cathode and electrolyte in the correct boxes to complete Fig. 5.2. [2] (ii) After a few minutes a coloured solid forms on the negative electrode. Name the solid and state its colour. name … colour … [2] (iii) Chlorine gas forms at the positive electrode and is tested with damp blue litmus paper. State the colour of chlorine gas and the final colour of the litmus paper. colour of chlorine gas … colour of litmus paper … [2]

13 0653/23/O/N/16 © UCLES 2016 [Turn over 6 (a) A student takes a flower apart and displays all the flower parts as shown in Fig. 6.1. petal F G Fig. 6.1 (i) Name flower parts F and G. F … G … [2] (ii) On Fig. 6.1 label and name a part of the flower that contains many haploid cells. Explain your answer. … …[2] (iii) The flower is insect-pollinated. Suggest one feature that helps with insect pollination. … …[1]

14 0653/23/O/N/16 © UCLES 2016 (b) A student investigates the rate of transpiration from a leafy twig under different conditions. Fig. 6.2 shows the apparatus he uses. scale water to reset bubble syringe rubber tubing capillary tube air bubble – moves up the tube as the shoot takes in water water reservoir shoot Fig. 6.2 • He measures how far the air bubble moves upwards in one minute. • He uses the syringe of water to reset the apparatus. • The student repeats the experiment under different environmental conditions. • His readings are shown in Table 6.1. Table 6.1 conditions distance moved by bubble in one minute / cm dry air at 22 °C 1.1 dry air at 27 °C 6.8 humid air at 22 °C (i) Explain why the distance the bubble moves increases when the temperature rises to 27 °C. … … … …[2]

15 0653/23/O/N/16 © UCLES 2016 [Turn over (ii) Suggest a possible reading for humid air at 22 °C. Explain your answer. reading … explanation … … …[1] (c) In the ground the plant takes in water at the roots. Fig. 6.3 shows the distribution of the tissues in the cross-sections of two similar roots of the same size. root 1 point S root 2 Fig. 6.3 (i) Suggest which root takes in water more quickly. Explain your answer. root … explanation … … …[1] (ii) On Fig. 6.3 draw a line to show a path taken by water from point S to the xylem. [2]

16 0653/23/O/N/16 © UCLES 2016 7 (a) Fig. 7.1 shows a wave generated in a string. One end of the string is fixed to a stand and clamp, while the other end is attached to a vibrator driven by an electric motor. Fig. 7.1 (i) The length of the string is 100 cm. State the wavelength of the wave motion shown in Fig. 7.1. … cm [1] (ii) On Fig. 7.1 draw a double-headed arrow ( or ) to show the amplitude of the wave. [1]

17 0653/23/O/N/16 © UCLES 2016 [Turn over (b) Fig. 7.2 shows part of the circuit diagram for the circuit used to drive the vibrator. The vibrator is driven by the electric motor. The speed of the motor is controlled by a variable resistor. M electric motor Fig. 7.2 Complete the circuit diagram by including the correct symbols in the correct places in the circuit for 1. a variable resistor to control the current through the motor, 2. a way of measuring the current through the motor. [3] (c) The variable resistor is adjusted so that the current through the motor is 2 A. The potential difference (p.d.) across the motor is 3.0 V. (i) State the name of the property of the motor given by the expression p.d. current . …[1] (ii) Calculate the value of this property and give the unit of your answer. Show your working. value of property = … unit …[2]

18 0653/23/O/N/16 © UCLES 2016 8 Fig. 8.1 shows the processes a student uses to make the salt, zinc sulfate. She reacts zinc carbonate powder with dilute sulfuric acid. powdered zinc carbonate dilute sulfuric acid glass rod gentle heat process C process B process A Fig. 8.1 (a) Name processes B and C. process B … process C … [2] (b) The student stirs the mixture to increase the speed of the reaction in process A. Suggest two other ways of increasing the speed of this reaction. 1. … 2. … [2] (c) (i) Deduce the identity of the salt and name the gas which forms when the student adds sodium carbonate to dilute sulfuric acid. salt … gas … [2] (ii) Describe what happens to the pH of the acid as it reacts with sodium carbonate. …[1] (iii) The formula of sodium carbonate is Na2CO3. State the number of different elements in sodium carbonate. … [1]

19 0653/23/O/N/16 © UCLES 2016 9 (a) Many human activities can affect the environment. Draw one line from each human activity to its effect. One line is drawn for you. human activity effect reduces the carbon dioxide concentration in water reduces the oxygen concentration in water can poison animals in the food chain adds methane to the air can lead to soil erosion adding sewage to rivers adding mercury to water cutting down forests keeping large numbers of cows [3] (b) Human activities can cause an increase in the concentration of carbon dioxide in the atmosphere. (i) State one large-scale activity of humans which increases the concentration of carbon dioxide in the atmosphere. … …[1] (ii) Explain why an increase in the concentration of carbon dioxide in the atmosphere is undesirable. … … … …[2]

20 0653/23/O/N/16 © UCLES 2016 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 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 0653/23 Paper 2 Core 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 23 © UCLES 2016 1 (a) (i) newton ; [1] (ii) because a force moves through a distance ; owtte [1] (b) (i) chemical ; potential / stored (elastic) ; kinetic ; [3] (ii) because some energy is still in longbow as e.g. vibration / is lost as sound / thermal energy / AVR ; [1] (c) (i) 180 km / h = 180 × 1000 / 3600 = 50 m / s ; [1] (ii) time = distance / speed ; (or equivalent) OR 100 / 50 = 2 (s) [2] 2 (a) particle number proton 12 neutron 12 ;; 2 or 3 correct boxes (1) 4 correct boxes (2) [2] (b) oxygen LHS ; magnesium LHS and magnesium oxide RHS ; [2] (c) A and hydrogen / H2 [1] (d) (i) sodium chloride ; sodium is a metal and chlorine is a non-metal ; [2] (ii) water ; hydrogen and oxygen are non-metals ; or hydrogen ; hydrogen is a non-metal ; [2]

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 23 © UCLES 2016 3 (a) (i) E vena cava / B pulmonary vein ; [1] (ii) valve ; prevents backflow of blood ; [2] (iii) oxygen content increases ; carbon dioxide content decreases ; [2] (b) (i) glucose + oxygen Æ carbon dioxide + water ; [1] (ii) any two from: protein synthesis ; cell division ; growth ; passage of nerve impulses ; maintenance of a constant body temperature ; [2] (c) any suitable activity, e.g. walking and activity is more energetic / active / uses more oxygen than sitting but less energetic / active / uses less oxygen than running ; [1] 4 (a) infra-red ; gamma radiation ultra-violet infra-red radio waves in correct box ; [2] (b) radiation ; convection ; [2] (c) any reasonable description of good insulation around tank ; [1] (d) any reasonable description of thermal expansion ; [1] (e) any reasonable problem caused by water freezing / ice forming ; [1]

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 23 © UCLES 2016 (f) ray from air to glass bent towards normal ; both angles marked correctly ; exit ray into vacuum roughly parallel to incident ray ; [3] 5 (a) ion reagent result copper(II) NaOH / NH3(aq) ; (light) blue ppt / solid ALLOW dark_blue solution if NH3 used ; chloride AgNO3 ; white ppt / solid ; [4] (b) (i) cathode ; anode ; electrolyte ; 3 correct (2) 1 or 2 correct (1) [2] (ii) copper ; brown / pink ; [2] (iii) (chlorine) (pale) green ; (litmus) white / bleached ; [2]

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 23 © UCLES 2016 6 (a) (i) F stigma / carpel ; G sepal ; [2] (ii) any anther correctly labelled ; contains the male gamete / pollen [2] (iii) any one from: large / brightly-coloured petals ; scented ; presence of nectar ; [1] (b) (i) any two from: increased rate of transpiration (at 27 °C) ; (due to) increased rate of evaporation / more water loss from plant ; molecules have more kinetic energy ; [2] (ii) any value less than 1.1 cm because the rate of evaporation / transpiration is lower in humid conditions ; [1] (c) (i) root 1 and it has root hairs cells (for absorption of water) ; [1] (ii) line drawn across the root through the cortex to the stele ; line finishes in the xylem ; [2] 7 (a) (i) 50 (cm) ; [1] (ii) correct arrow ; [1] (b) variable resistor symbol ; ammeter symbol ; all connected in series to form a complete circuit ; [3] (c) (i) resistance ; [1] (ii) (3 / 2 =) 1.5 ; ohm(s) / Ω ; [2]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0653 23 © UCLES 2016 8 (a) process B filter(ing) / filtration ; process C evaporation / crystallisation ; [2] (b) increase concentration (of acid); increase temperature ; [2] (c) (i) sodium sulfate / Na2SO4 ; carbon dioxide / CO2 ; [2] (ii) (pH number) increases / goes to 7 ; [1] (iii) three / 3 ; [1] 9 (a) can lead to soil erosion adding sewage to rivers adds methane to the air adding mercury to water reduces the carbon dioxide concentration in water cutting down forests reduces the oxygen concentration in water keeping large numbers of cows can poison animals in the food chain [3] (b) (i) burning fossil fuels / deforestation ; [1] (ii) causes the temperature of the atmosphere to rise / global warming / carbon dioxide is a greenhouse gas ; consequence, e.g. flooding / melting ice caps / changes in weather patterns ; AVP [2]