Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2008 Oct/Nov Paper 3 · Variant 1

This document consists of 25 printed pages and 3 blank pages. IB08 11_0654_03/5RP © UCLES 2008 [Turn over *7629302318* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/03 Paper 3 (Extended) October/November 2008 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 a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES Answer all questions. A copy of the Periodic Table is printed on page 28. 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. www.XtremePapers.com

2 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 1 Fig. 1.1 shows a blood capillary between alveoli in the lungs. The alveoli provide the gas exchange surface. cell in wall of capillary red blood cell white blood cell airspace in alveolus cell in wall of alveolus elastic fibres Fig. 1.1 (a) Describe what happens in the red blood cells as they pass through the capillaries in the lungs. [2] (b) White blood cells are able to move out of blood capillaries through tiny gaps in their walls. Suggest the function of the white blood cell in the alveolus. [1]

3 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (c) (i) Describe how air is made to move into the lungs during inhalation. [3] (ii) Suggest why there are elastic fibres around the alveoli. [1] (d) Explain how the structures shown in Fig. 1.1 make the alveoli an efficient surface for gaseous exchange. [3] (e) Describe how gas exchange takes place in the leaf of a plant. [3]

4 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 2 (a) A student is given the apparatus shown in Fig. 2.1. coil sensitive ammeter steel bar magnet plastic strip connecting wire Fig. 2.1 Describe as fully as you can, how the student would select from the apparatus provided, and use it to produce an electric current. [3] (b) Electric power is produced at power stations using generators. A simple generator is shown in Fig. 2.2. N S slip rings brush contacts Fig. 2.2 (i) Explain why a current is induced in the coil when it rotates. [1]

5 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (ii) Explain why the current is at a maximum when the coil is horizontal, and at a minimum when the coil is vertical. [2]

6 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 3 A student investigates the reaction between magnesium and dilute acid Y. Fig. 3.1 shows the metal being added to the acid contained in a test-tube, and also the same tube some time later. 50 40 30 20 10 50 40 30 20 10 acid Y magnesium magnesium chloride solution Fig. 3.1 (a) (i) Name acid Y. [1] (ii) Describe and explain one observation which the student would have made during the reaction. [2] (iii) The student noticed that, within a short time, the piece of magnesium completely reacted. Predict and explain what would be observed if another small piece of magnesium were added to the solution in the tube shown on the right of Fig. 3.1. [2]

7 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (b) Explain why a metal such as magnesium is a good conductor of electricity. You should draw a labelled diagram to help your explanation. [3] PLEASE TURN OVER FOR QUESTION 3(c)

8 © UCLES 2008 0654/03/O/N/08 For Examiner's Use (c) Magnesium alloys are widely used in making parts for aircraft and racing car engines. Table 3.1 shows some incomplete data about one type of magnesium alloy. Table 3.1 element moles in 100 g of alloy mass in 100 g of alloy /g magnesium zinc 0.055 3.575 zirconium 0.011 (i) Calculate the mass of zirconium in 100 g of the alloy. Zirconium is in Period 5 of the Periodic Table. Show your working. [2] (ii) Calculate the mass and hence the number of moles of magnesium in 100 g of the alloy. Show your working. [3]

9 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use 4 In the 1930s, farmers growing sugar cane in tropical parts of Australia had problems with insect pests, such as lacebugs, that ate the crop. Cane toads, Bufo marinus, were introduced from central America to try to solve the problem. Cane toads kill and eat insects and other small animals. Fig. 4.1 shows a cane toad. Fig. 4.1 (a) State one feature of a cane toad, visible in Fig. 4.1, which shows that it is an amphibian. [1] (b) Name the genus to which cane toads belong. [1] (c) Use the information above to write a food chain involving cane toads. For each organism, state whether it is a producer or a consumer. [2]

10 © UCLES 2008 0654/03/O/N/08 For Examiner's Use (d) The cane toads did help to control the insect population. However, they also ate many other small animals, including species of rare and endangered mammals. The cane toads have spread rapidly from the place to which they were introduced, into other areas of Australia. Cane toads have become a serious pest. Biologists noticed that the cane toads that first arrived in a new area tended to have longer legs than the original cane toads that were introduced into Queensland. They thought that perhaps this happened because toads with longer legs could travel faster than other toads. They collected toads with different leg lengths, and measured the distance the toads travelled in 24 hours. The results are shown in Fig. 4.2. –0.8 –0.4 0 0.4 0.8 2000 1750 1500 1250 1000 distance travelled in 24 hours / m difference in leg length / mm compared with normal Fig. 4.2 (i) Calculate the speed at which a toad with normal leg length travelled. Show your working. [2] (ii) Suggest why it could be an advantage to a cane toad to move into a new area where there are no other cane toads present. [1]

11 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (iii) The researchers suggested that cane toads might be evolving into toads with longer legs. Using all the information provided, outline how this might happen. [4]

12 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 5 (a) Some countries use nuclear fission reactors to generate electricity. (i) What is meant by the term nuclear fission? [1] (ii) State one advantage and one disadvantage of generating electricity using nuclear reactors. advantage disadvantage [2] (b) When nuclear fuel is used in a power station, ionising radiation is released. Table 5.1 shows some information about three types of ionising radiation. Table 5.1 radiation ionising power deflection by electric field alpha very strong small beta moderate large gamma weak none (i) Explain how alpha, beta and gamma radiations can be separated from each other by passing them across an electric field. [4]

13 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (ii) Explain why alpha radiation is the most ionising. [1] (iii) Describe the effect of ionising radiation on living things. [1] (iv) Why are radioactive sources stored in lead containers? [1]

15 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use 6 Fig. 6.1 shows crude oil (petroleum) being extracted from sedimentary rock under the sea. sea bed natural gas crude oil A B C layers of sedimentary rock oil drilling rig Fig. 6.1 (a) The oil shown in Fig. 6.1 is found only in rock layer B and not in layers A or C. Suggest the property of rock B which is different from rocks A and C, and which allows it to contain oil. [1]

16 © UCLES 2008 0654/03/O/N/08 For Examiner's Use (b) Crude oil is a mixture of different hydrocarbon molecules. A typical hydrocarbon molecule is shown in Fig. 6.2. carbon atom hydrogen atom hydrocarbon molecule key Fig. 6.2 Write the graphical (displayed) formula of the hydrocarbon shown in Fig. 6.2, and explain whether it is an alkane or an alkene. [2] (c) Fig. 6.3 shows a simplified diagram of an important industrial process involving hydrocarbons. mixture of large alkane molecules mixture of alkanes and alkenes catalyst in the form of very small pieces of solid high temperature Fig. 6.3 (i) Name the process shown in Fig. 6.3. [1] (ii) Suggest a process which could be used to separate the mixture of alkanes and alkenes. [1]

17 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (iii) A research chemist is investigating two catalysts, P and Q, for use in the process shown in Fig. 6.3. Describe a simple chemical test for alkenes. Suggest how the chemist could use this test to discover which catalyst, P or Q, produces a mixture containing the larger amount of alkenes. [3]

18 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 7 Fig. 7.1 shows the female reproductive system. A B C D Fig. 7.1 (a) Name the structures labelled A, B, C and D. A B C D [2] (b) Fig. 7.2 shows how the thickness of the uterus lining changes during the menstrual cycle. 1st 7th 14th date in June 21st 28th thickness of uterus lining Fig. 7.2 (i) Suggest the date on which menstruation began. [1]

19 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (ii) Suggest the date on which ovulation (the release of an egg from an ovary) occurred. [1] (c) AIDS can be transmitted from one person to another during sexual intercourse. Explain how this transmission can take place. [2] (d) Humans, like all mammals, use internal fertilisation, whereas fish use external fertilisation. (i) Explain what is meant by external fertilisation. [2] (ii) Explain why external fertilisation is used only by animals that reproduce in water. [1] (iii) Mammals produce only a few eggs at a time, whereas fish produce thousands. Suggest why. [2]

20 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 8 An airline passenger enters an airport. (a) He buys some hot food at the restaurant and carries it away in a polystyrene container. Explain why a polystyrene container is used to keep food hot. [1] (b) He then moves up an escalator (moving staircase) as shown in Fig. 8.1. 6 m 20 m Fig. 8.1 (i) The passenger weighs 900 N. Calculate the work done lifting the passenger a vertical distance of 6 m up the escalator. State the formula that you use and show your working. formula working [2] (ii) State the potential energy the passenger has gained when he reaches the top of the escalator. [1]

21 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (c) The passenger places three pieces of luggage onto a conveyor belt as shown in Fig. 8.2. A B C Fig. 8.2 Each piece of luggage has a different mass. mass of A = 12 kg mass of B = 15 kg mass of C = 22 kg (i) What is the momentum of the luggage before the conveyor belt starts to move? Explain your answer. [2] (ii) When the conveyor belt is switched on, the luggage moves at a constant speed of 0.5 m / s. Which piece of luggage A, B or C has the most momentum? Explain your answer. [1] (iii) At one point the conveyor belt turns left. The luggage on the belt continues to move at a constant speed. Does the momentum of the luggage change as it turns left on the conveyor belt? Explain your answer. [1]

22 © UCLES 2008 0654/03/O/N/08 For Examiner's Use (d) Radar uses microwaves with a frequency of about 10 000 MHz (1010 Hz). A short pulse is sent from a transmitter, reflected by an aircraft and picked up by a receiver next to the transmitter. (i) Explain the meaning of the term frequency. [1] (ii) Microwaves travel at 300 000 000 m / s (3x108 m / s). Calculate the wavelength of the microwaves. State the formula that you use and show your working. formula working [2] (iii) Radio signals are electromagnetic waves. They can be either digital or analogue. State the difference between these two terms. [1]

23 © UCLES 2008 0654/03/O/N/08 [Turn over For Examiner's Use (e) A large crane is being used to build a new terminal building at the airport. The crane in Fig. 8.3 is balanced. 5000 N load 25 000 N 10 m movable counterbalance supporting tower Fig. 8.3 (i) Calculate the moment of the load about the supporting tower of the crane. State the formula that you use and show your working. formula working [2] (ii) Calculate the distance of the crane’s counterbalance from the crane’s supporting tower. Show your working. [2]

24 © UCLES 2008 0654/03/O/N/08 For Examiner's Use 9 Fig. 9.1 shows the apparatus and substances used by a student to make an electrical cell. V zinc electrode copper electrode electrolyte Fig. 9.1 (a) Suggest a compound which the student could dissolve in water to make the electrolyte. Explain your answer briefly. [2] (b) The student knows that the electrode made from the more reactive metal is the negative electrode of the cell. The student has three other electrodes made of unknown metals X, Y and Z. The results of experiments involving all five metals are shown in Table 9.1. Table 9.1 experiment negative electrode positive electrode cell voltage / volts 1 zinc copper 1.1 2 X copper 2.7 3 Y copper 1.5 4 X Z 3.2

25 © UCLES 2008 0654/03/O/N/08 For Examiner's Use (i) Use the results shown in Table 9.1 to place the metals in order of reactivity. Copper has already been placed in position. (most reactive) copper (least reactive) [2] (ii) State and explain briefly which one of the metals above has atoms which change into ions most easily. [2] (c) Copper is a transition metal which forms two oxides. The chemical formulae of these oxides are: Cu2O copper(I) oxide CuO copper(II) oxide The formula and electrical charge of an oxide ion is O2-. Deduce the difference between the copper ion in copper(I) oxide and that in copper(II) oxide. Show how you obtained your answer. [3] (d) Zinc can be obtained industrially by the electrolysis of concentrated zinc sulphate solution which contains zinc ions, Zn2+. Describe and explain what happens to zinc ions in the solution in order to convert them into zinc atoms. [3]

28 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. University of 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. © UCLES 2008 0654/03/O/N/08 Group 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 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 Sulphur 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 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 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2008 question paper 0654 CO-ORDINATED SCIENCES 0654/03 Paper 3 (Extended Theory), maximum raw mark 100 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. All Examiners are instructed that alternative correct answers and unexpected approaches in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. Mark schemes must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the October/November 2008 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0654 03 © UCLES 2008 1 (a) take up oxygen / become oxygenated / oxygen goes into them ; not just 'carry oxygen' by diffusion ; oxygen, combines with / taken up by/ received by, haemoglobin ; haemoglobin changes to oxyhaemoglobin / oxyhaemoglobin formed ; [max 2] (b) destroy / engulf / produce antibodies against, bacteria / pathogens / foreign objects ; or protect lungs / alveoli, against bacteria / pathogens / foreign objects ; [1 max] (c) (i) ref. to diaphragm (muscles) ; ref. to intercostal muscles / muscles between ribs ; (either) contract ; (but do not give this if one is contracting and the other relaxing) increases volume of, thorax / lungs / chest cavity ; which decreases pressure (inside thorax / lungs / chest cavity) ; air moves from high to low pressure ; [max 3] (ii) to allow alveoli to, expand when breathing in / return to normal size when breathing out [1] (d) capillary wall is, thin / one cell thick ; not ‘thin cell wall’ wall of alveolus is, thin / one cell thick ; not ‘thin cell wall’ small distance for gases to diffuse ; so takes less time / diffusion is faster / diffusion is easier ; large surface (area) ; so diffusion can take place more rapidly ; (ignore refs to diffusion gradient) max 3 (e) through stomata ; by diffusion ; allow diffusion anywhere appropriate (net movement) of carbon dioxide in during light and oxygen in during dark / allow converse ; ref. to air spaces (inside leaf) ; ref. to large surface area of (spongy mesophyll) cells inside leaf ; [max 3] [Total: 13] 2 (a) place magnet in coil ; magnet or coil need to be moving or implied ; connect other end of coil to meter ; not just 'complete the circuit' [3] (b) (i) wire moving across a magnetic field / idea that wire is experiencing a change in magnetic field ; allow: there is a change in flux through the coil [1] (ii) magnetic field is changing most / cuts most (magnetic) lines of force ; rate of, cutting / changing, magnetic field is greatest when horizontal ; is zero when vertical / cuts no (magnetic) lines of force ; [max 2] [Total: 6]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0654 03 © UCLES 2008 3 (a) (i) hydrochloric ; [1] (ii) bubbles of gas / effervescence ; hydrogen is a product ; temperature increases / tube feels warm ; reaction is exothermic / heat evolved ; metal dissolves ; metal reacts to form a soluble product ; metal rises to surface ; supported by bubbles of gas / made buoyant by gas ; [max 2] (iii) it would react (like the first piece) / specific observation ; because acid, remains / was in excess ; [2] (b) diagram shows lattice of, atoms / ions ; delocalised electrons ; ref to electrical conductivity explained in terms of ease of electron movement / energy transfer between electrons ; [3] (c) (i) evidence of use of mass = molar mass x number of moles / Ar ; Ar of Zr = 91 ; give this if 91 appears anywhere mass = 0.011 x 91 = 1.00(1) ; [max 2] (ii) mass of Mg = 100 – (3.575 + 1.001) = 95.424g ; Ar Mg = 24 ; give this if 24 appears anywhere moles of Mg = 95.424 ÷ 24 = 3.976 ; [3] [Total: 13] 4 (a) no scales, feathers or fur on skin / smooth skin ; [1] (b) Bufo ; [1] (c) sugar cane lacebugs cane toads ; producer consumer consumer ; [2] (d) (i) 1550 m in 24 hours / so 1550 ÷ 24 ; = 64.6 metres per hour / .018 m per s / other correct unit ; [2] (ii) more food / less competition / no limiting factors ; [1]

Page 4 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0654 03 © UCLES 2008 (iii) idea that difference in leg length is due to genes ; more likely to arrive in new area ; so more likely to survive (because more food, less competition) ; and more likely to reproduce ; pass on, genes / alleles / mutation, for long legs to offspring ; ref to long legged toads more easily escape predators ; [max 4] [Total: 11] 5 (a) (i) nucleus (of atom) splits ; [1] (ii) advantage – no global warming / CO2 emissions / no reduction in fossil fuels reserves / or small amount of fuel produces large amount of, electricity / energy ; disadvantage – radiation leaks / high decommissioning costs / waste disposal / expensive to build / expensive to maintain / expensive to keep safe ; [max 2] (b) (i) alpha and beta deflected in opposite directions ; because they have opposite charges ; alpha to negative and beta to positive ; this also gets mp1 gamma not charged and not deflected ; [4] (ii) largest / most massive / most charged, particle ; [1] (iii) cancer / mutations / damage DNA / radiation burns / damages cells / ; [1] (iv) lead only lets some gamma escape / lead is good at absorbing, gamma / all types of radiation ; [1] [Total: 10] 6 (a) it is porous / permeable / description of porosity ; [1] (b) H C H H C C C C C H H H H H H H H H H H ; 1 (alkane) contains only single bonds (between carbon atoms) / is saturated / contains maximum possible number of H atoms / fits formula CnH2n+2 ; [1]

Page 5 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0654 03 © UCLES 2008 (c) (i) (catalytic) cracking ; [1] (ii) fractional distillation ; [1] (iii) bromine (solution) ; orange to colourless / decolourised, with alkenes ; take equal amounts of product mixture for both catalysts ; the mixture which decolourises, the greater amount of bromine / faster / produces lightest colour, has the more alkenes ; [max 3] [Total: 8] 7 (a) A oviduct / Fallopian tube B ovary C vagina / cervix D uterus one mark for any two correct ; ; [2] (b) (i) date between (June) 5th – 8th ; [1] (ii) date between 20th – 28th ; [1] (c) virus / HIV ; in body fluids / description ; not 'in male gametes' or 'in sperm' [2] (d) (i) fusion of, sperm and egg / male and female gamete / male and female nucleus ; outside the (female’s) body / after the eggs are laid / in the water ; [2] (ii) sperm, could not survive in air / need liquid to swim in ; [1] (iii) external fertilisation, less efficient than internal / many eggs not fertilised ; eggs develop outside body with external fertilisation so not protected / fewer embryos survive ; [2] [Total: 11] 8 (a) (good thermal) insulator / poor conductor ; [1] (b) (i) (work =) force x distance ; = 900 x 6 = 5400 J ; [2] (ii) 5400 J ; allow ecf [1] (c) (i) zero ; no velocity ; accept 'no speed' [2] (ii) C (no mark) mass is largest ; [1]

Page 6 Mark Scheme Syllabus Paper IGCSE – October/November 2008 0654 03 © UCLES 2008 (iii) yes (no mark) idea that as direction changes so does (velocity and therefore) momentum / momentum is a vector quantity ; [1] (d) (i) number of waves per unit time ; [1] (ii) velocity = frequency x wavelength /wavelength = velocity/frequency ; 300 000 000/10 000 000 000 = 0.03 m ; [2] (iii) digital series of pulses / on off or analogue has complete range of values ; [1] (e) (i) moment = force x distance ; accept load instead of force = 5000 x 10 = 50 000 Nm ; if say moment = mass x distance but then do calculation correctly and give correct unit, can get second mp [2] (ii) distance = 50 000/25 000 ; = 2 m ; allow ecf from (i) [2] [Total: 16] 9 (a) any ionic (ignore solubility issues) ; must contain ions / it is ionic / must be able to conduct ; [2] (b) (i) X (most) Y zinc (copper) Z (least ;; (all correct for [2] two correct for [1]) [2] (ii) X ; it is the most reactive ; [2] (c) evidence of balancing charge to find copper ion charge ; deduces Cu+ in Cu2O ; deduces Cu2+ in CuO ; statement to effect that Cu2+ has one less electron than Cu+ / or similar ; [max 3] 2Cu+ + O2– arrow Cu2O gets mp 1 and 2 because it implies charge neutralised (d) zinc ions / they, move to cathode / negative electrode ; reference to Zn ions positive and attracted to negative electrode ; zinc ions gain electrons ; two electrons each / are discharged ; Zn2+ + 2e– arrow Zn gets mp 3 and 4 [max 3] [Total: 12]