Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2010 Oct/Nov Paper 3 · Variant 1

This document consists of 26 printed pages and 2 blank pages. IB10 11_0654_31/3RP © UCLES 2010 [Turn over *0573530616* 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 0654/31 Paper 3 (Extended) October/November 2010 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 2010 0654/31/O/N/10 For Examiner's Use 1 Fig. 1.1 shows the apparatus a student used to study the rate of reaction between 1.0 g of powdered metal and dilute hydrochloric acid. test-tube full of water water dilute hydrochloric acid conical flask 1.0 g powdered metal Fig. 1.1 When the student tilted the conical flask, the acid mixed with the powdered metal. If a reaction occurred, any gas which was produced collected in the test-tube, pushing the water out. The student measured the time taken for the test-tube to fill with gas. (a) (i) Name the gas produced when metals react with dilute hydrochloric acid. [1] (ii) State the formula of the ion which is present in relatively high concentrations in all acids. [1] (b) The student used the apparatus and method described above to compare the rates of reaction between dilute hydrochloric acid and three powdered metals, X, Y and Z. The results the student obtained are shown in Table 1.1. Table 1.1 metal mass of metal / g time for gas to fill the test-tube / seconds X 1.0 154 Y 1.0 28 Z 1.0 76

3 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (i) The student was careful to ensure that the only variable (factor) which differed between the experiments was the type of metal. State two variables, other than the mass and surface area of the metals, which the student must keep the same in each experiment. 1 2 [2] (ii) Explain how the results show that the rate of reaction was the lowest when metal X was used. [1] (iii) The student repeated the experiment with metal Y but this time he used a single piece of metal which had a mass of 1.0 g. State how the rate of reaction would differ from the experiment in which 1.0 g of powdered metal was used. Explain your answer in terms of the collisions between atoms in the surface of the metal and ions in the solution. [3]

4 © UCLES 2010 0654/31/O/N/10 For Examiner's Use (c) When magnesium reacts with dilute hydrochloric acid, HCl, one of the products is magnesium chloride, MgCl2. (i) Construct a balanced symbolic equation for this reaction. [2] (ii) Magnesium chloride is a compound which causes hardness in water. Describe briefly how the process of ion exchange is used to soften hard water. You may draw a simple diagram if it helps you to answer this question. [2]

5 © UCLES 2010 0654/31/O/N/10 [Turn over BLANK PAGE Please turn over for Question 2.

6 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 2 Fig. 2.1 shows a mobile phone (cell phone). mobile phone containing a battery Fig. 2.1 (a) Energy is stored inside the mobile phone in a battery. Describe the energy changes taking place when the battery is being charged. [2] (b) The quality of digital signals is maintained far better than that of analogue signals. Explain why. [2]

7 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (c) The strength of phone cases can be tested by dropping the phones onto different surfaces from a height of 2 m. A phone of mass 80 g is dropped onto a concrete path. The case breaks when it hits the concrete. When an identical mobile phone is dropped onto a soft carpet from the same height, the case does not break. (i) State the momentum of each phone after it has landed on the surface. [1] (ii) As a phone was about to hit the concrete path, its momentum was 1.2 kg m / s. It took 0.03 s to stop. The force it experienced as it hit is given by the formula force = stop to taken time momentum in change Calculate this force. Show your working. [2] (iii) The phones that hit the concrete and the soft carpet had the same change in momentum. Suggest why the phone dropped onto the soft carpet did not break. [2]

8 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 3 Fig. 3.1 shows a generalised reflex arc. neurone Y central nervous system neurone X neurone Z receptor effector Fig. 3.1 (a) (i) Name the neurones labelled X, Y and Z. X Y Z [3] (ii) Name one part of the central nervous system in which neurone Y might be found. [1] (b) A student hears a sudden, loud bang. Receptors in his ear respond to the sound by generating electrical impulses in neurone X. These impulses travel along the reflex arc, eventually reaching an effector. Suggest what the effector could be in this reflex, and how it would respond. effector response [2] (c) Another reflex action involves the secretion of saliva into the mouth in response to the smell of food. (i) Describe the role of saliva in the digestion of food. [2]

9 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (ii) Explain why it is necessary for most types of food that we eat to be digested. [2] (iii) On the axes below, sketch a curve to show how the activity of enzyme from human saliva would vary with temperature. 0 10 20 30 temperature / °C activity of enzyme in saliva 40 50 60 [2]

10 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 4 In jet engines, hydrocarbon molecules from the jet fuel mix with air and burn. This releases a large amount of energy and produces a mixture of waste gases. These waste gases pass out through the back of the jet engine into the atmosphere. jet engine air waste gases (a) Fig. 4.1 shows a molecule of octane, which is a typical hydrocarbon molecule in jet fuel. key carbon atom hydrogen atom octane Fig. 4.1 (i) State the chemical formula of octane. [1] (ii) Complete the word equation below for the complete combustion of octane. octane + + [2] (b) The mixture of waste gases coming from the jet engine contains a large amount of the free element nitrogen, N2, which exists naturally in the air. The atoms in a nitrogen molecule are held together by a triple covalent bond as shown in the displayed formula below. N N (i) State the number of outer electrons in a single nitrogen atom. [1]

11 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (ii) Complete the bonding diagram below to show how the outer electrons are arranged around the atoms in a nitrogen molecule. N N [2] (iii) The temperature inside the jet engine is very high. Suggest why most of the nitrogen molecules which pass through the engine do not break up into individual atoms. [2]

12 © UCLES 2010 0654/31/O/N/10 For Examiner's Use (c) Table 4.1 shows information about some metallic materials. Table 4.1 material strength density mild steel very high very high aluminium low low duralumin (an aluminium alloy) very high low (i) Duralumin is used in the manufacture of aircraft. Explain why the properties of this material make it suitable for this purpose. [2] (ii) A sample of duralumin has a mass of 50.00 g and contains 1.73 moles of aluminium. Calculate the percentage by mass of aluminium in this sample of duralumin. Show your working. [3]

13 © UCLES 2010 0654/31/O/N/10 [Turn over BLANK PAGE Please turn over for Question 5.

14 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 5 A student investigated the relationship between the potential difference across a lamp and the current passing through it. (a) Fig. 5.1 shows her results. 0 2 4 6 8 10 12 0.6 0.5 0.4 0.3 0.2 0.1 0 potential difference / V current / A × × × × × × × Fig. 5.1 (i) What is the current when the potential difference is 6 V? [1]

15 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (ii) Calculate the resistance of the lamp when the potential difference is 6 V. State the formula that you use and show your working. formula used working [2] (b) A student was given two bar magnets and a bar of soft iron. She carried out the following experiments. (i) She brought the magnets close together with like poles facing. N S S N State what she observed. [1] (ii) She brought the soft iron bar towards one of the magnets. N S iron bar State what she observed. [1]

16 © UCLES 2010 0654/31/O/N/10 For Examiner's Use (c) Fig. 5.2 shows a strip of aluminium foil hung between the poles of a magnet. When the current is switched on, the foil experiences a force as shown. N S force aluminium foil Fig. 5.2 (i) Explain why a force is produced. [2] (ii) State two changes which would increase the size of the force acting on the aluminium foil. 1 2 [2]

17 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (d) A transformer used in a television set has 100 turns on the primary coil. The potential difference across the primary coil is 240 V and the potential difference across the secondary coil is 35 000 V. Calculate the number of turns on the secondary coil. Use the formula Vp / Vs = Np / Ns. Show your working. [2]

18 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 6 The gray wolf, Canis lupus, is a predator. In Wisconsin, Canada, the wolves’ diet consists mainly of white-tailed deer, beavers, snowshoe hares and mice. (a) White-tailed deer eat grasses and other plants. (i) Construct a food chain including white-tailed deer and wolves. [1] (ii) Sketch a pyramid of biomass for the food chain you have constructed in (i). Label the trophic levels in your pyramid. [3] (iii) With reference to your answers in (i) and (ii), suggest why wolves are rarer than white-tailed deer. [2]

19 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (b) People used to shoot gray wolves. In 1978, a conservation programme for gray wolves began in Wisconsin and people were no longer allowed to shoot them. The main causes of death of wolves are disease, starvation and accidents such as collisions with vehicles. Fig. 6.1 shows the size of the gray wolf population in Wisconsin between 1986 and 2010. It also shows the predicted wolf population if the conservation programme is successful. 1985 1990 1995 2000 2005 2010 2015 2020 500 400 300 200 100 0 number of wolves year Fig. 6.1 (i) Suggest why the population of gray wolves in Wisconsin is not expected to increase beyond about 500 individuals, even if they are no longer killed by humans. [2] (ii) Some people in Wisconsin are opposed to the wolf conservation programme. Explain why it is important to conserve species such as the gray wolf. [2]

20 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 7 Copper metal reacts with oxygen gas to form copper oxide. (a) Table 7.1 shows information about two different types of copper oxide. Table 7.1 name colour chemical formula copper(II) oxide black CuO copper(I) oxide red Cu2O (i) Copper is a transition metal. State one property, shown in Table 7.1, which is typical of transition metals. [1] (ii) The formula of the oxide ion is O2-. Use the formula of copper(I) oxide to deduce the charge of the copper ion in this compound. Show your working. [2]

21 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (b) Fig. 7.1 shows apparatus and materials needed for the electrolysis of aqueous solutions of ionic compounds, using graphite electrodes. power supply – + switch Fig. 7.1 Table 7.2 shows the observations made when solutions of three compounds, W, X and Y, were each electrolysed. Table 7.2 compound in solution observation at the cathode observation at the anode W bubbles of gas bubbles of gas which bleach damp litmus paper X orange / pink solid layer forms bubbles of gas which bleach damp litmus paper Y bubbles of gas orange solution produced (i) On Fig 7.1, clearly label the anode and the electrolyte. [2] (ii) Suggest the name of compound X. [1] (iii) Name the gas produced at the cathode when compound W is electrolysed. [1] (iv) Explain which compound, W, X or Y, could be potassium bromide. compound [2]

22 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 8 (a) Explain why plants need light for photosynthesis. [2] (b) A student fixed a piece of black paper over a leaf, which was still attached to the plant. He left the plant in the sun for two days. He then removed the leaf from the plant and tested it for starch, after removing the black paper. (i) Describe how the student should test the leaf for starch. [4] (ii) Fig. 8.1 shows the leaf before and after he did the starch test. before testing after testing black paper Fig. 8.1 Complete the diagram of the leaf after testing in Fig. 8.1, using labels to show the colours of each part. Do not colour the diagram. [2]

23 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (c) In daylight, plant leaves take in carbon dioxide and give out oxygen. In darkness, they take in oxygen and give out carbon dioxide. Explain why this happens. [3]

24 © UCLES 2010 0654/31/O/N/10 For Examiner's Use 9 Fig. 9.1 shows a rock that is falling from the top of a cliff into the river below. cliff river falling rock Fig. 9.1 (a) The rock accelerates downwards at 9.8 m / s2. The mass of the rock is 2000 g. Calculate the weight of the rock. State the formula that you use and show your working. formula used working [2]

25 © UCLES 2010 0654/31/O/N/10 [Turn over For Examiner's Use (b) Fig. 9.2 is a speed-time graph for the motion of the rock. This graph ignores the effect of air resistance on the rock. 50 40 30 20 10 0 0 1 2 3 4 5 time / s speed m / s Fig. 9.2 (i) Calculate the kinetic energy of the rock as it hits the water. State the formula that you use and show your working. formula used working [3] (ii) Calculate the height of the cliff. Show your working. [2]

26 © UCLES 2010 0654/31/O/N/10 For Examiner's Use (c) The rock has an irregular shape. It has a mass of 2000 g and a volume of 700 cm3. (i) Calculate the density of the rock. State the formula that you use and show your working. formula used working [2] (ii) Describe how you could find the volume of an irregularly shaped object such as a rock. You should state the apparatus you would use and the measurements you would need to make. [2]

27 © UCLES 2010 0654/31/O/N/10 (d) The rock contains radioactive substances emitting high levels of ionising radiation. (i) State how the radioactivity could be detected. [1] (ii) Explain why it would be dangerous for a person to handle this rock without proper protection. [1]

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 2010 0654/31/O/N/10 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 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 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 2010 question paper for the guidance of teachers 0654 CO-ORDINATED SCIENCES 0654/31 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, which would have considered the acceptability of alternative answers. 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 2010 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: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 31 © UCLES 2010 1 (a) (i) hydrogen ; [1] (ii) H+ ; allow H3O+ [1] (b) (i) acid concentration ; temperature ; degree of agitation ; allow size of test-tube [max 2] (ii) time taken for gas to fill test-tube was greatest ; [1] (iii) rate is lower (with single piece) ; surface area (of single piece) is lower ; fewer collisions per second / lower collision frequency (between acid and (atoms in) metal (surface)) ; [3] (c) (i) Mg + 2HCl → MgCl2 + H2 ;; (formulae then look for balanced) [2] (ii) reference to the (granular) resin (beads) ; magnesium ions, removed / stick to the resin ; sodium / hydrogen, ions (detach from resin and) enter the water ; [max 2] [Total: 12] 2 (a) electrical energy to chemical energy ; (also some of) electrical energy to heat ; ignore light [2] (b) less distortion ; less interference ; [2] (c) (i) zero ; ignore units [1] (ii) force = 1.2 / 0.03 ; allow ecf from (i) = 40 N ; [2] rate of change of momentum slower larger force from concrete / smaller force from carpet ; stopping force acted / energy transferred, over a longer period of time ; [2] [Total: 9]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 31 © UCLES 2010 3 (a) (i) X sensory (neurone) ; Y relay / intermediate (neurone) ; A association / connector (neurone) Z motor / effector (neurone) ; [3] (ii) brain / spinal cord ; allow suitable named parts, e.g. medulla, grey matter [1] (b) any muscle ; jump / any other suitable response ; [2] (c) (i) contains amylase ; changes starch to maltose / sugar ; [2] (ii) to produce small molecules (from large ones) ; so that the (small) molecules can be absorbed ; pass through gut wall / move into the blood ; so they can be used by cells ; [2 max] (iii) curve rises then falls ; peak between 30 °C and 40 °C ; [2] [Total: 12] 4 (a) (i) C8H18 ; [1] (ii) + + (octane) oxygen water carbon dioxide LHS ; RHS ; must be words – but allow one mark for completely correct balanced equation [2] (b) (i) 5 ; [1] (ii) three shared pairs ; one non-bonding pair on both atoms ; [2] (iii) very strong bond (between the atoms) ; much energy needed to break bond / insufficient energy to break the bond ; [2] (c) (i) high strength, for safety / resist breakage / because high forces on airframe in flight ; low density, to reduce weight / reduce fuel cost ; [max 2] (ii) Ar of aluminium = 27 ; mass of aluminium = 1.73 × 27 = 46.74(g) ; allow other methods of working percentage in duralumin = (46.74 ÷ 50.00) × 100 = 93.4(2)% [3] [Total: 13]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 31 © UCLES 2010 5 (a) (i) 0.47 A ; [1] (ii) resistance = voltage / current ; = 6/0.47 = 12.8 Ω ; e.c.f. [2] (b) (i) magnets repel ; [1] (ii) iron bar attracted to magnet ; [1] (c) (i) magnetic field produced by current flowing through aluminium foil ; this interacts with, other magnetic field / stronger magnet ; [2] (ii) increase current / voltage ; increase magnetic field / stronger magnet ; ignore bigger magnet [2] (d) working, e.g. Ns = Np × Vs / Vp = 100 × 35000 / 240 = 14 583 (allow correct rounding to 2 significant figures) [2] [Total: 11] 6 (a) (i) grasses / other plants → white-tailed deer → wolves ; [1] (ii) wolves secondary consumers white-tailed deer primary consumers grasses / other plants producers three rectangles drawn as above ; each labelled with name of organism ; each labelled with name of trophic level ; [3] (iii) energy lost along food chains ; (approx.) 90% lost / only 10% passed on ; less energy available for, higher trophic levels / for wolves ; [2] (b) (i) ref. to limiting factors ; e.g. not enough food / more disease / competition for space ; [2] (ii) maintain biodiversity ; idea that loss of one species affects others in ecosystem ; ethical / moral reason / ref. tourism / scientific research ; [2 max] [Total: 10]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 31 © UCLES 2010 7 (a) (i) coloured compounds or variable, valency / ion charge / oxidation state ; [1] (ii) Cu+ ; working shows (or heavy implication of) need for charge balance ; [2] [reject unexplained “criss-cross” diagrams] (b) (i) anode labelled ; electrolyte labelled ; [2] (ii) copper chloride ; must be name, not formula [1] (iii) hydrogen ; must be name, not formula [1] (iv) (Y) cathode gas is hydrogen ; so reactive metal present could be potassium ; bromide ions negative so go to anode ; bromine is orange (and would form from bromide and anode) ; [max 2] [Total: 9] 8 (a) provides / is, energy ; to allow carbon dioxide to combine with water ; A to split water molecules [2] (b) (i) place leaf in boiling water ; place in hot alcohol (alcohol should be heated in a water bath for safety) ; dip in water (to soften) ; add iodine (solution) ; [4] (ii) area covered by paper shown on diagram ; orange-brown where paper was, blue-black elsewhere ; [2] (c) respire all the time ; during daylight, photosynthesise more than they respire ; respiration takes in oxygen and produces carbon dioxide, photosynthesis vice versa ; [3] [Total: 11]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0654 31 © UCLES 2010 9 (a) (force =) mass × acceleration ; A weight = mass × gravity = 9.8 × 2 = 19.6 N ; [2] (b) (i) KE = ½ mv2 ; speed is 40 m / s ; = ½ × 2 × 1600 = 1600 J ; [3] (ii) distance = under graph / other suitable working ; height = 80 m ; [2] (c) (i) density = mass / volume ; = 2000 / 700 = 2.86 g / cm3 ; [2] (ii) use, displacement can / measuring cylinder / graduated container ; place object in and measure, displaced water / difference in volume ; [2] (d) (i) Geiger counter / Geiger-Müller tube / any other suitable ; [1] (ii) ionisation within cells / damages cells / kills cells / damages DNA / causes mutation / radiation burns / cancer / radiation sickness ; [1] [Total: 13]