Cambridge IGCSE Physical Science 0652 — 2015 Oct/Nov Paper 2 · Variant 1

This document consists of 18 printed pages and 2 blank pages. DC (NF/FD) 101765/4 © UCLES 2015 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 2 2 3 9 2 1 8 0 0 5 * PHYSICAL SCIENCE 0652/21 Paper 2 (Core) October/November 2015 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, graphs, tables or rough working. 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 0652/21/O/N/15 © UCLES 2015 1 Carbon-12 and carbon-14 are isotopes of carbon. (a) Explain what is meant by the term isotope. … … … [2] (b) Carbon-14 can be represented by 14 6C. State what the numbers 6 and 14 stand for. 6 … 14 … [2] (c) Complete Fig. 1.1 to show the electron arrangement in an atom of carbon-14. & Fig. 1.1 [1]

3 0652/21/O/N/15 © UCLES 2015 [Turn over 2 Fig. 2.1 shows a beam fixed into a wall at one end. C marks the centre of mass of the beam. Point X acts as the pivot. & < ; Fig. 2.1 (a) Draw an arrow to show where the weight of the beam acts and the direction in which it acts. [2] (b) A man of mass 80 kg stands on the beam at point Y. (i) Calculate the weight of the man and give the unit. Use g = 10 m / s2. weight … unit … [2] (ii) The distance from X to Y is 6.0 m. Calculate the moment at point X produced by the man when he is at point Y. moment = … N m [2] (iii) State and explain how the moment produced at X changes as the man walks towards the wall. … … … [2]

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5 0652/21/O/N/15 © UCLES 2015 [Turn over 3 Use words from the list below to complete Table 3.1. Each word may be used once, more than once, or not at all. air brass bromine chlorine graphite nitrogen steel sulfur Table 3.1 description substance an alloy containing zinc a solid non-metallic element a gaseous mixture an element which is a good conductor of electricity a gaseous element used in water purification [5]

6 0652/21/O/N/15 © UCLES 2015 4 Fig. 4.1 shows a piece of apparatus, viewed from above. Four different metal strips are fixed to a wooden ring. ZRRGHQULQJ DOXPLQLXP LURQ FRSSHU EUDVV Fig. 4.1 Fig. 4.2 shows an experiment using the apparatus. A match head is placed on the end of each metal strip. The strips are then heated at the centre. match heads heat Fig. 4.2 Each of the match heads ignites after a different length of time. This is shown in Table 4.1. Table 4.1 metal strip time for match head to ignite / minutes aluminium 4 brass 3 copper 1 iron 8

7 0652/21/O/N/15 © UCLES 2015 [Turn over (a) Name the form of thermal energy transfer which causes the match to ignite. … [1] (b) List the metals in order of the speed at which they transfer thermal energy. fastest … … … slowest … [2]

8 0652/21/O/N/15 © UCLES 2015 5 Sodium chloride, NaCl, is an ionic compound containing sodium ions and chloride ions. (a) (i) Explain how a sodium ion is formed from a sodium atom. … … [1] (ii) Give the symbol for a chloride ion and the total number of electrons it contains. symbol … number of electrons … [2] (b) In the box, draw a dot and cross diagram to show the electrons in a molecule of hydrogen chloride, HCl. Include outer electrons only. [2] (c) Sodium chloride can be made by reacting hydrogen chloride with an alkali. Name a suitable alkali and the other product or products of the reaction with this alkali. alkali … other product(s) … … [2]

9 0652/21/O/N/15 © UCLES 2015 [Turn over 6 Fig. 6.1 shows an illuminated object O in front of a plane mirror. Two rays of light are shown leaving object O. mirror 2 UD\ UD\ Fig. 6.1 (a) (i) On Fig. 6.1, mark the position of the image of object O formed by the mirror and label it I. [1] (ii) Complete ray 1 showing how it is reflected from the mirror. [1] (iii) Complete ray 2 showing how it is reflected from the mirror. [1] (iv) Identify and label, with the letter r, the angle of reflection that ray 2 makes with the mirror. [1] (v) Complete the diagram to show how the image I is formed. [2] (vi) Mark the position of an eye for the image to be seen and label it E. [1] (b) State the relationship between the angle of incidence and the angle of reflection. … … [1] (c) The image formed in a plane mirror is upright and the same size as the original object. State one other property of the image. … [1]

10 0652/21/O/N/15 © UCLES 2015 7 Calcium carbonate, CaCO3, and ammonium sulfate, (NH4)2SO4, may be used by farmers to improve crop yields. (a) Complete Table 7.1 by writing the names of the three other elements present in ammonium sulfate and the relative numbers of atoms of each in the compound. One element is done for you. Table 7.1 element relative number of atoms sulfur 1 … … … … … … [3] (b) Calculate the relative molecular mass of calcium carbonate, CaCO3. [Relative atomic masses: Ar: Ca, 40; C, 12; O, 16] relative atomic mass = … [2] (c) Many crops grow best in neutral or weakly alkaline soils. Calcium carbonate is added to acidic soils to increase their pH. (i) Suggest the pH number of a weakly acidic soil. … [1] (ii) State the pH number of neutral soil. … [1]

11 0652/21/O/N/15 © UCLES 2015 [Turn over 8 A student hangs two balloons from the ceiling as shown in Fig. 8.1a. The student then rubs the two balloons on his jumper. The balloons now hang as shown in Fig. 8.1b. FHLOLQJ FRWWRQWKUHDGV EDOORRQV Fig. 8.1a Fig. 8.1b (a) Explain why the balloons are no longer touching. … … … [3] (b) A fine mist of water is sprayed near the balloons. The balloons move back so that they are touching each other as shown in Fig. 8.2. Fig. 8.2 Explain why the balloons move back to this position. … … … [2]

12 0652/21/O/N/15 © UCLES 2015 9 Copper is a transition element. (a) Transition elements are metals. State one other characteristic of transition elements. … [1] (b) Name a non-metallic element in the same period as copper. … [1] (c) Copper is found in the Earth’s crust, either as an ore or ‘native’. (i) Name an ore of copper. … [1] (ii) Name another metal which is also found ‘native’ in the Earth’s crust. … [1] (iii) Give a reason why these metals are found ‘native’. … [1]

13 0652/21/O/N/15 © UCLES 2015 [Turn over (d) A student sets up the apparatus as shown in Fig. 9.1. iron(II) sulfate solution copper test-tube A test-tube B copper(II) sulfate solution iron Fig. 9.1 She observes the apparatus after one hour. (i) State what she sees in each test-tube after one hour. test-tube A … … test-tube B … … [2] (ii) Explain these observations. … … [1]

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15 0652/21/O/N/15 © UCLES 2015 [Turn over 10 Ethyne (acetylene), C2H2, is used as a fuel when metals are welded together. Ethyne burns in oxygen to form carbon dioxide and water in an exothermic reaction. (a) (i) State what is meant by exothermic. … [1] (ii) Write a balanced equation for the burning of ethyne underneath the word equation. ethyne + oxygen carbon dioxide + water … [2] (b) (i) Name the harmful gas that is formed when ethyne burns in a limited supply of oxygen. … [1] (ii) Explain why this gas is harmful. … … [1] (c) Ethyne is a member of a homologous series. (i) State one characteristic of a homologous series. … … [1] (ii) Ethene, C2H4, and ethane, C2H6, are members of different homologous series. Explain how ethene and ethane are different in terms of their bonding. … … … [2]

16 0652/21/O/N/15 © UCLES 2015 11 A student draws the circuit diagram shown in Fig. 11.1. $ IXVH 9 6 Fig. 11.1 (a) He has drawn the wrong symbol for a fuse. Draw the correct symbol for a fuse in the space below. [1] (b) The student constructs the circuit shown in his diagram. He closes switch S and the reading on the ammeter is 3.2 A. Calculate the resistance of the lamp. Give the unit. resistance = … unit … [3] (c) Fuses of the following ratings are available: 3 A, 5 A, and 13 A. State which fuse would be most suitable to use in the circuit shown in Fig. 11.1 and give an explanation for your choice. fuse rating … explanation … … … [3]

17 0652/21/O/N/15 © UCLES 2015 [Turn over (d) The student adds an identical second lamp, in parallel with the original lamp. (i) Complete Fig. 11.2 to show the two lamps connected in parallel in the circuit. $ IXVH 9 6 Fig. 11.2 [1] (ii) When switch S in the second circuit is closed the fuse blows. Explain why the fuse blows. … … … [2]

18 0652/21/O/N/15 © UCLES 2015 12 The graph in Fig. 12.1 shows the results from an experiment to measure the half life of a radioactive isotope. activity / s 0 0 10 20 30 time / s 40 50 60 1000 2000 3000 4000 5000 Fig. 12.1 (a) Suggest why the points do not lie precisely on the drawn curve. … … [1] (b) (i) Determine the initial activity of the sample. … [1] (ii) Use your graph to calculate the half life of the isotope. Show on your graph how you determined your answer. half life = … s [2]

19 0652/21/O/N/15 © UCLES 2015 (c) Radioactive isotopes can be dangerous to health. Give one precaution that should be taken when using radioactive isotopes. … … [1]

20 0652/21/O/N/15 © UCLES 2015 Group The Periodic Table of the Elements 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 231 147 237 244 243 247 247 251 252 257 258 259 260 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 209 210 222 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 † 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 223 Ra Radium 88 a X b a = relative atomic mass X = atomic symbol b = atomic (proton) number Key DATA SHEET * 58–71 Lanthanoid series † 90–103 Actinoid series The volume of one mole of any gas is 24dm3 at room temperature and pressure (r.t.p.). 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. CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International General Certificate of Secondary Education MARK SCHEME for the October/November 2015 series 0652 PHYSICAL SCIENCE 0652/21 Paper 2 (Core Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 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 2015 0652 21 © Cambridge International Examinations 2015 1 (a) atom of an element with same number of proton / proton number ; [1] different number of neutrons / nucleon or neutron number; [1] (if no reference to ‘number’ 1 max, for both proton and nucleon) (b) atomic / proton number ; [1] mass / nucleon number ; [1] (c) 2 electrons in first level and 4 in outer level; [1] [Total 5] 2 (a) Arrow from C ; [1] vertically downwards ; [1] (b) (i) Use of mass × g (= 80 × 10) ; [1] 800 N (accept use of (9.8 or 9.81 N kg–1) ; [1] (ii) Use of weight × distance (= 800 × 6.0) (ecf) ; [1] = 4800 (N m) ; [1] (iii) decreases ; [1] (moment = force × distance from X) distance decreases owtte ; [1] [Total 8] 3 brass ; [1] graphite / sulfur ; [1] air ; [1] graphite ; [1] chlorine ; [1] [Total 5] 4 (a) conduction ; [1] (b) copper fastest, iron slowest ; [1] brass quicker conductor than aluminium ; [1] [Total 3]

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2015 0652 21 © Cambridge International Examinations 2015 5 (a) (i) loses one / an electron ; [1] (ii) Cl – ; [1] 18 ; [1] (b) 8 electrons round chlorine ; [1] shared pair between hydrogen and chlorine ; [1] (c) sodium hydroxide / sodium oxide ; [1] Water ; [1] OR sodium carbonate / hydrogencarbonate ; [1] water AND carbon dioxide ; [1] (accept correct formulae) [Total 7] 6 (a) (i) I clearly marked equal distance behind the mirror as object is in front and in line with the object ; [1] (accept very small angle between incident and reflected ray, < 5°) (ii) Ray 1 correctly reflected back along its own path ; [1] (iii) Ray 2 correctly reflected ; [1] (iv) normal drawn and ‘r’ correctly identified ; [1] (v) Ray 1 correctly continued along its own path ; [1] Ray 2 correctly continued along its own path ; [1] (vi) E at a suitable point with between the rays [1] (b) angle of reflection = angle of incidence ; [1] (c) virtual (accept cannot be projected onto a screen) ; [1] [Total 9] 7 (a) nitrogen – 2 ; [1] hydrogen – 8 ; [1] oxygen – 4 ; [1] (can be listed in any order with the correct number) (award one mark if all three names correct and no other marks gained)

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2015 0652 21 © Cambridge International Examinations 2015 (b) 40 + 12 + 48 ; [1] 100 ; [1] (correct final answer with no working scores 2 marks, ignore any unit given) (c) (i) any number between 4 and 6.9 ; [1] (4 is acceptable but 7 is not) (ii) 7 ; [1] [Total 7] 8 (a) balloons are charged (by rubbing) [1] (accept charge transferred from jumper to balloon or vice versa) both have same charge (accept both positive / negative) ; [1] like charges repel ; [1] (b) water conducts (charge) ; [1] water removes charge / balloons discharged ; [1] [Total 5] 9 (a) any one from: coloured ions / compounds / ; more than one ion formed / different oxidation states / variable valencies ; useful catalysts / form complexes ; high densities / melting points ; [1] (accept conducts electricity or energy) (b) arsenic / selenium / bromine / krypton ; [1] (c) (i) malachite / copper pyrites ; [1] (ii) gold / silver / mercury/platinum ; [1] (iii) unreactive ; [1]

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2015 0652 21 © Cambridge International Examinations 2015 (d) (i) no reaction / no change / OWTTE ; [1] copper formed / iron dissolves / solution turns colourless; [1] (ii) iron is more reactive than copper ; [1] [Total 8] 10 (a) (i) heat / energy given out ; [1] (ii) 2C2H2 + 5O2 → 4CO2 + 2H2O ; [2] (all formulae correct – 1 mark; correct balancing – 1 mark) (b) (i) carbon monoxide ; [1] (ii) poisonous / toxic / prevents transport of oxygen in blood / bonds with haemoglobin ; [1] (c) (i) members differ by CH2 / same general formula / functional group ; [1] (accept similar chemical properties / physical properties increase down series) (ii) ethane has carbon-carbon single bond ; [1] ethaene has carbon-carbon double bond ; [1] [Total 8] 11 (a) correct circuit diagram for fuse ; [1] (accept ) (b) use of R = V / I ( =12 / 3.2) ; [1] = 3.75 ; [1] ohm or Ω ; [1] (c) 5 A ; [1] must be greater than 3.2 A (accept for 13 A fuse) ; [1] and smallest above 3.2 A / relevant comment re 13 A fuse ; [1] (If 3 A is chosen and reason given is that it is the nearest to current allow 1c). (d) (i) lamp correctly drawn in parallel with the original lamp ; [1] (ii) circuit current / current through fuse now larger ; [1] greater than 5 A / = 6.4 A ; [1] [Total 10]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2015 0652 21 © Cambridge International Examinations 2015 12 (a) randomness of decay ; [1] (b) (i) 4600 s–1 (Bq) ; [1] (ii) Indication on graph of finding time at which count rate halves ; [1] 25 ± 2 s ; [1] (c) Protective clothing / use tongs / short exposure time / shielding etc. ; [1] [Total 5]