Choose words from the list to complete the sentences below. In an atom, the particles with a negative charge are called...

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1 Q This question is about the structure of atoms (a) Choose words from the list to complete the sentences below electrons ions neutrons protons In an atom, the particles with a negative charge are called Particles in the nucleus with no charge are called An atom has no overall charge because is has the same number of electrons and (3) (b) Two isotopes of the element carbon are: 4 C and C 6 6 Complete the table of information for these two isotopes ATOMIC NUMBER MASS NUMBER NUMBER OF PROTONS NUMBER OF NEUTRONS Isotope 6 C Isotope 6 C 6 6 () (Total 5 marks) Q (a) The formula for the chemical compound magnesium sulphate is MgSO 4 Calculate the relative formula mass (M r )of this compound (Show your working) () Page of 50

2 (b) Magnesium sulphate can be made from magnesium and dilute sulphuric acid This is the equation for the reaction Mg + H SO 4 MgSO 4 + H Calculate the mass of magnesium sulphate that would be obtained from 4g of magnesium (Show your working) Answer g () (Total 4 marks) Q3 The formula for the chemical compound magnesium sulphate is MgSO 4 Calculate the relative formula mass (M r ) of this compound (Show your working) (Total marks) Page of 50

3 Q4 Calculate the formula mass (Mr), of the compound calcium hydroxide, Ca (OH) (Show your working) (Total 3 marks) ## Atoms of calcium, phosphorus and fluorine are represented below, each with its mass number and proton number (a) Use this information to complete the table CALCIUM PHOSPHOROUS FLUORINE Number of protons in the nucleus 0 9 Number of neutrons in the nucleus 0 6 Number of electrons 5 9 (3) (b) Calcium and fluorine atoms can combine to form the compound calcium fluoride, CaF The fluoride ion is represented by F (i) Explain how the fluorine atom forms a fluoride ion () (ii) How is the calcium ion represented? () Page 3 of 50

4 (c) Phosphorus and fluorine form a covalent compound, phosphorus trifluoride Complete the sentences below which are about this compound Phosphorus trifluoride is made up of phosphorus and fluorine These are joined together by sharing pairs of to form phosphorus trifluoride (3) (d) (i) Sodium chloride, an ionic compound, has a high melting point whereas paraffin wax, a molecular compound, melts easily Explain why () (ii) Molten ionic compounds conduct electricity but molecular compounds are nonconductors, even when liquid Explain why () (Total 4 marks) Q6 The information on the Data Sheet will be helpful in answering this question (a) Calculate the formula mass (M r ) of the compound iron (III) oxide, Fe O 3 (Show your working) (3) Page 4 of 50

5 (b) Calculate the mass of iron produced when 3g of iron (III) oxide is completely reduced by aluminium The reaction is shown in the symbol equation: Fe O 3 + Al Fe + Al O 3 (Show your working) Answer = grams (3) (Total 6 marks) Q7 You will find it helpful to use the information on the Data Sheet when answering this question In the nucleus of an aluminium atom are: and 3 protons 4 neutrons (a) Complete these sentences (i) The mass number of the aluminium atom is (ii) In an atom of aluminium there are electrons () (b) Why is an aluminium atom electrically neutral? () Page 5 of 50

6 (c) Complete the table for the element fluorine PARTICLE NUMBER OF PROTONS NUMBER OF NEUTRONS NUMBER OF ELECTRONS Fluorine atom 9 9 Fluoride atom 0 (3) (Total 7 marks) Q8 (a) The formula for ammonia is NH 3 What does the formula tell you about each molecule of ammonia? (3) (b) Ammonia is used to make nitric acid (HNO 3 ) Calculate the formula mass (Mr) for nitric acid (Show your working) (3) (Total 6 marks) Q9 The two carbon atoms represented below are isotopes ISOTOPE ISOTOPE 4 mass number C C 6 proton number 6 (a) Describe two ways in which the isotopes are similar () Page 6 of 50

7 (b) Describe as fully as you can one way in which they are different () (Total 4 marks) Q0 (a) The equation for the reaction that takes place when ammonium chloride is heated is: NH 4 Cl(s) NH 3 (g) + HCl (g) ammonium chloride ammonia hydrogen chloride The diagram shows how a teacher demonstrated this reaction The demonstration was carried out in a fume cupboard (i) Apart from the gases normally in the atmosphere, which two gases would be at X? and () (ii) Name the white solid that has formed at Y () (iii) Why was the demonstration carried out in a fume cupboard? () Page 7 of 50

8 (iv) Complete the four spaces in the passage The chemical formula of ammonia is NH 3 This shows that there is one atom of and three atoms of in each of ammonia These atoms are joined by bonds that are formed by sharing pairs of electrons This type of bond is called a bond (4) (b) Electrons, neutrons and protons are sub-atomic particles (i) Complete the three spaces in the table Name of sub-atomic particle Relative mass Relative charge + 0 () (ii) Which two sub-atomic particles are in the nucleus of an atom? and () (Total 0 marks) Q (a) Atoms are made of sub-atomic particles Complete the six spaces in the table Name of sub-atomic particle Relative mass Relative charge Neutron (3) Page 8 of 50

9 (b) Complete the spaces in the sentences (i) The atomic number of an atom is the number of in its nucleus and is equal to the number of if the atom is not charged () (ii) The mass number of an atom is the total number of and in its nucleus () (c) The table gives information about the atoms of three elements Number of electrons in: Name of element Chemical symbol st shell nd shell 3 rd shell Fluorine F 7 0 Neon Ne 8 0 Sodium Na 8 Two of these elements can react together to form a chemical compound (i) What is the name and the formula of this compound? Name Formula () (ii) What type of bonding holds this compound together? () Page 9 of 50

10 (iii) Explain, in terms of electron transfer, how the bonding occurs in this compound () (Total 0 marks) ## In this question you will need to use the following information: Relative atomic masses: H ; O 6; Mg 4 The volume of one mole of any gas is 4 dm 3 at room temperature and atmospheric pressure The diagram shows a chemical reaction taking place in a conical flask The balanced equation for this reaction is: Mg(s) + HCl(aq) MgCl (aq) + H (g) (a) Write a balanced ionic equation for this reaction () Page 0 of 50

11 (b) Calculate the mass of magnesium required to produce 050 g of hydrogen Show clearly how you work out your final answer and give the unit Mass = () (c) (i) Draw a diagram to show how the electrons are arranged in a hydrogen molecule () (ii) What is the name of the type of chemical bond between the hydrogen atoms in a hydrogen molecule? () (d) The chemical formula for hydrogen peroxide is H O Calculate, to the nearest whole number, the percentage, by mass, of hydrogen in hydrogen peroxide Show clearly how you work out your answer Percentage = % () (Total 8 marks) Page of 50

12 Q3 Electrons, neutrons and protons are sub-atomic particles (a) Complete the six spaces in the following table Name of sub-atomic particle Relative mass Relative charge 0 (3) (b) An aluminium atom has 3 electrons How are these arranged in shells around the nucleus? () (c) Chromium atoms have 4 protons and 8 neutrons (i) How many electrons does each neutral chromium atom have? () (ii) What is the mass number of chromium? () (d) What change occurs to an atom which undergoes the process of reduction in a chemical reaction? () Page of 50

13 (e) The diagram shows part of the ionic lattice of a sodium chloride crystal Explain why the ions in this lattice stay in place (3) (Total 0 marks) Q4 Ammonium chloride, NH 4 Cl, is made up of nitrogen, hydrogen and chlorine atoms (i) Complete the table to show the number of atoms of each element present in NH 4 Cl Element Number of atoms in NH 4 Cl nitrogen hydrogen chlorine () Page 3 of 50

14 (ii) Calculate the relative formula mass of ammonium chloride, NH 4 Cl (Relative atomic masses: H =, N = 4, Cl = 355) Relative formula mass = () (Total 3 marks) Q5 Ammonia is a very important chemical (a) The table shows the percentage of ammonia used to make different substances SUBSTANCES MADE FROM AMMONIA PERCENTAGE (%) OF AMMONIA USED fertilisers 75 nitric acid 0 nylon 5 others 0 Shade on the pie chart the percentage of ammonia used to make nitric acid () Page 4 of 50

15 (b) Ammonia gas is made by the reaction between nitrogen gas and hydrogen gas Write a word equation to represent this reaction + () (c) Nitrogen is one of the raw materials used to make ammonia Nitrogen is obtained from air This pie chart shows the proportion of nitrogen, oxygen and other gases in air Label the area which represents the proportion of nitrogen in air () (d) An artificial fertiliser contains compounds with the formulae: NH 4 NO 3 and KCl (i) Use the Data Sheet to help you answer this question Name the elements in the compound NH 4 NO 3 3 () (ii) Use the Data Sheet to help you answer this question Name the compound KCl () (e) (i) Ammonium nitrate is one type of artificial fertiliser Calculate the relative formula mass of ammonium nitrate NH 4 NO 3 (Relative atomic masses: H =, N = 4, O = 6) () Page 5 of 50

16 (ii) Use your answer to part (f)(i) to help you calculate the percentage by mass of nitrogen present in ammonium nitrate NH 4 NO 3 () (Total 9 marks) Q6 Quicklime can be converted to slaked lime The equation which represents this reaction is shown below CaO (s) + H O (l) Ca(OH) (s) quickline slaked line (i) Why do farmers sometimes add slaked lime to acidic soil? () (ii) Use these relative atomic masses: H = ; O = 6; Ca = 40 to calculate the relative formula mass (M r ) of quicklime CaO slaked lime Ca(OH) () (iii) Calculate the mass of slaked lime that could be made from 000 kg of quicklime Mass of slaked lime kg () (Total 5 marks) Page 6 of 50

17 Q7 Use these relative atomic masses: H = ; O = 6; Ca = 40 to calculate the relative formula mass (M r ) of quicklime CaO slaked lime Ca(OH) (Total marks) Q8 Limestone (CaCO 3 ) is a raw material On strong heating it is converted to calcium oxide which is a very useful substance (a) Calculate the formula mass (M r ) of calcium carbonate M r of calcium carbonate = () (b) About 60 million tonnes of calcium oxide is made in Britain each year Calculate the mass of calcium carbonate needed to make this amount of calcium oxide Mass of calcium carbonate needed = million tonnes (4) (c) Water is added to some of the calcium oxide produced in a process known as slaking The product of this reaction is used to make plaster CaO (s) + H O () Ca(OH) (s) (i) Give the chemical name of Ca(OH) () Page 7 of 50

18 (ii) What is the physical state of the Ca(OH) formed in the reaction? () (Total 8 marks) Q9 Brine, a solution containing sodium chloride in water, can be used to manufacture chlorine, hydrogen and sodium hydroxide A student sets up a simplified model of the industrial cell (a) The electron arrangements of some atoms are shown here H O 6 Na 8 C 87 (i) Use the relevant electron arrangements to describe the bonding in water () Page 8 of 50

19 (ii) Use the relevant electron arrangements to describe the bonding in sodium chloride (3) (b) Use the atomic structures of and to explain the meaning of the term isotopes (3) (Total 8 marks) Q0 Follow the steps to find the percentage of iron in iron oxide Relative atomic masses: O 6; Fe 56 (i) Step Calculate the relative formula mass of iron oxide, Fe O 3 () (ii) Step Calculate the total relative mass of just the iron atoms in the formula, Fe O 3 () Page 9 of 50

20 (iii) Step 3 Calculate the percentage (%) of iron in the iron oxide, Fe O 3 Percentage of iron % () (Total 3 marks) Q The diagrams show three isotopes of potassium (i) In what way does the atomic structure show you that they are all atoms? () (ii) Explain why these three atoms are called isotopes of potassium (3) (Total 4 marks) Page 0 of 50

21 Q As the world population increases there is a greater demand for fertilisers (a) Explain what fertilisers are used for () (b) The amount of nitrogen in a fertiliser is important (i) How many nitrogen atoms are there in the formula, NH 4 NO 3? () (ii) Work out the relative formula mass of ammonium nitrate, NH 4 NO 3 Relative atomic masses: H ; N 4; O 6 Relative formula mass of ammonium nitrate = () (Total 4 marks) Page of 50

22 Q3 Uranium metal can be produced by reacting uranium hexafluoride with calcium UF 6 + 3Ca 3CaF + U (a) Describe how calcium and fluorine bond together to form calcium fluoride The electron arrangement of each atom is shown (5) (b) Uranium has two main isotopes, and Use these as examples to explain what is meant by the word isotope (4) Page of 50

23 (c) At the start of a reaction there was 745 g of uranium hexafluoride, UF 6 Relative atomic masses: F 9; U 35 (i) Calculate the relative formula mass of uranium hexafluoride, UF 6 Relative formula mass UF 6 = g () (ii) Calculate the mass of uranium that would be produced from 345 g of uranium hexafluoride Mass of uranium = g () (Total marks) Q4 The chemical equation for the formation of iron is: Fe O 3 (s) + 3CO(g) Fe(s) + 3CO (g) Calculate the relative formula mass of iron oxide, Fe O 3 Relative atomic masses: O 6; Fe 56 Relative formula mass Fe O 3 = (Total marks) Page 3 of 50

24 Q5 There is molten rock below the Earth s solid outer crust The rock remains molten because the radioactive decay of isotopes such as uranium, thorium and potassium releases heat energy (i) Explain how this released heat energy is thought to cause the recycling of rocks (4) (ii) Two isotopes of potassium are shown Explain what is meant by isotopes You must include numbers of electrons, neutrons and protons in your explanation (4) (Total 8 marks) Page 4 of 50

25 Q6 Calcium carbonate tablets are used to treat people with calcium deficiency (a) Calculate the relative formula mass (M r ) of calcium carbonate Relative atomic masses: C = ; O = 6; Ca = 40 Relative formula mass = () (b) Calculate the percentage of calcium in calcium carbonate, CaCO 3 Percentage of calcium = % () (c) Calculate the mass of calcium in each tablet Mass of calcium = g () Page 5 of 50

26 (d) An unwanted side effect of this medicine is that it can cause the patient to have wind (too much gas in the intestine) The equation below represents the reaction between calcium carbonate and hydrochloric acid (the acid present in the stomach) CaCO 3 (s) + HCl (aq) CaCl (aq) + H O (l) + CO (g) Suggest why the patient may suffer from wind () (Total 7 marks) Q7 Iron ore contains iron oxide (i) Calculate the relative formula mass of iron oxide, Fe O 3 Relative atomic masses: O = 6; Fe = 56 Answer = () (ii) Calculate the percentage by mass of iron in iron oxide Percentage of iron = % () (iii) Calculate the mass of iron that could be extracted from 000 kg of iron oxide Use your answer to part (c) (ii) to help you with this calculation Mass of iron = kg () (Total 5 marks) Page 6 of 50

27 Q8 Aluminium is a useful metal (a) The atomic number (proton number) of aluminium is 3 Complete the diagram to show the electronic structure of an aluminium atom Use crosses (x) to represent the electrons () (b) Aluminium is used as the electrical conductor for overhead power cables Explain why metals are good conductors of electricity () (Total 3 marks) Page 7 of 50

28 Q9 Toothpastes often contain fluoride ions to help protect teeth from attack by bacteria Some toothpastes contain tin(ii) fluoride This compound has the formula SnF (a) Calculate the relative formula mass (M r ) of SnF Relative atomic masses: F = 9; Sn = 9 Relative formula mass (M r ) = () (b) Calculate the percentage by mass of fluorine in SnF Percentage by mass of fluorine = % () Page 8 of 50

29 (c) A tube of toothpaste contains g of SnF Calculate the mass of fluorine in this tube of toothpaste Mass of fluorine = g () (d) The diagram represents the electron arrangement of a fluorine atom Explain how a fluorine atom can change into a fluoride ion, F () (Total 7 marks) Q30 Toothpastes often contain fluoride ions to help protect teeth from attack by bacteria Some toothpastes contain tin(ii) fluoride This compound has the formula SnF Page 9 of 50

30 (a) Calculate the relative formula mass (M r ) of SnF Relative atomic masses: F = 9; Sn = 9 Relative formula mass (M r ) = () (b) Calculate the percentage by mass of fluorine in SnF Percentage by mass of fluorine = % () (c) A tube of toothpaste contains g of SnF Calculate the mass of fluorine in this tube of toothpaste Mass of fluorine = g () Page 30 of 50

31 (d) The diagram represents the electron arrangement of a fluorine atom Explain how a fluorine atom can change into a fluoride ion, F () (Total 7 marks) Page 3 of 50

32 M (a) electrons neutrons protons for mark each 3 (b) mass number no of neutrons 4 8 for mark each [5] M (a) Mg S O ( 4) or 64 / evidence of all A r s but (M r ) = 0 gains mark gains marks (b) evidence that 4(g) magnesium would produce 0(g) mapesiurn sulphate gains mark or correct scaling by /6 but 0(g) magnesium sulphate gains marks [credit error carried forward from (a) with full marks in (b)] [4] M3 Mg S O ( 4) or 64 / evidence of all A r s correct [so mark] gains mark but (M r ) = 0 No ECF gains marks [] Page 3 of 50

33 (ii) Ca + gains mark M4 Ca = 40 (OH) = (6 + ) or 34 but M r = 74 gain mark each gains 3 marks [3] M5 (a) Calcium Phosphorus Fluorine No of protons 5 No of neutrons 0 No of electrons 0 for mark each 3 (b) (i) gain of electron(s) from (atoms) (of) calcium for mark but superscript only Ca + / Ca ++ gains marks (c) atoms electrons molecule(s) not compound each for mark 3 (d) (i) ideas that ionic strong forces between ions molecular weak forces between molecules each for mark Page 33 of 50

34 (ii) ideas that ionic ions/charged particles are free to move molecular -molecules do not carry a charge each for mark [4] ## (a) Fe [56 ] or O 3 [6 3] or 48 each gain mark but M r = 60 gains 3 marks 3 (b) [Fe O 3 + A Fe + A O 3 ] 60 (NB Credit if unworked (or value (or value but should be totalled) from (a)) from (a)) gains mark but 3 g of Fe O 3 3/60 but = 4 gains marks gains 3 marks 3 [6] M7 (a) (i) 7 (ii) 3 each for mark (b) each proton has a/ positive charge and each electron has a/ negative charge OR electrons and protons have (equal but) opposite charges there are equal numbers of protons and electrons in the atom/ so charges cancel or balance (each other) each for mark Page 34 of 50

35 (c) PARTICLE NUMBER OF PROTONS NUMBER OF NEUTRONS NUMBER OF ELECTRONS Fluorine atom 0 Fluoride atom 9 0 each for mark 3 [7] M8 (a) reference to hydrogen (atoms) ) nitrogen (atoms) ) but not molecules each for mark ratio of N to 3H atoms for further mark or nitrogen atom and 3 hydrogen atoms (ignore any incorrect statements about nature of bonding) 3 (b) evidence of H = N = 4 O = 6 gains mark but H = N = 4 O = 6 3 or 48 gains marks but 63 gains 3 marks 3 [6] M9 (a) same number/six electrons; same number/six protons; react in same way not same element or both carbon any two for mark each Page 35 of 50

36 (b) different number of neutrons gains mark but or C has two more neutrons different mass number gains mark or gains marks but two mass units bigger C has 8 neutrons while C has 6 neutrons gains marks [4] M0 (a) (i) ammonia and hydrogen chloride both required either order accept formulae if correct in every detail (ii) ammonium chloride / NH 4 Cl do not credit ammonia chloride (iii) the fumes / gases / are poisonous / toxic or ammonia and hydrogen chloride are poisonous / toxic / lethal accept just ammonia is poisonous / toxic accept just hydrogen chloride is poisonous / toxic accept vapour is poisonous / toxic do not credit just fumes are dangerous or harmful Page 36 of 50

37 (iv) nitrogen do not credit N/N hydrogen do not credit H/H molecule do not credit compound or mole covalent accept single / molecular (b) (i) proton neutron electron either all three correct or one or two correct however do not credit a response which is repeated (ii) protons and neutrons both required in either order [0] M (a) both correct in each row electron () allow negative 0 allow neutral or none proton + () allow positive (b) (i) protonselectrons both correct in correct order (ii) protonsneutrons both correct in either order Page 37 of 50

38 (c) (i) sodium fluoride do not credit sodium fluorine NaF must be correct in every detail do not credit NAF and the like (ii) ionic accept ion (bonding) do not credit ironic or iron (bonding) (iii) electron transferred from sodium to fluorine accept electron transferred from metal to non-metal either positive sodium ion and negative fluoride ion or correctly identified by the symbols Na+ and F- accept positive sodium ion and negative fluorine ion or attracted because have opposite charge(s) or (atoms/ions) form an (ionic) lattice or (atoms/ions) form a crystal eg or both marks may be gained by a suitable dot and cross diagram [0] M (a) Mg + H + Mg + + H * reactants correct in every detail * products correct in every detail if the spectator ions are sown then () mark should be credited but only if they are shown correctly on both sides eg Mg + H + + CI - Mg + + CI - + H (b) 4 (parts) of magnesium (parts) of hydrogen or equally clear working (so) 6 grams/g (are needed) unit required Page 38 of 50

39 (c) (i) two (and no more) atoms shown to be sharing their single electrons examples do not credit if anything which contradicts the impression that these are hydrogen atoms (ii) (single) covalent (bond) (d) ( 00) = 6 (just 6 is worth () mark) 00 = 6 or similar is (0) do not credit and the like [8] M3 (a) proton + () both required neutron both required electron () both required 3 (b) 83 accept words or diagram to this effect (c) (i) 4 (ii) 5 (d) any one of gains one or more electrons accept gains an electron becomes an anion do not credit becomes an ion becomes a negative ion Page 39 of 50

40 (e) sodium ions have a (single) positive charge and chloride ions have a (single) negative charge do not credit chlorine ions but allow this error to be carried forward ions with opposite charge are attracted (to each other) or the positive ions and the negative ions are attracted (to each other) or the sodium ions and the chloride ions are attracted (to each other) (positive and negative) ions are arranged alternatively (in each direction or dimension) or ions with the same charge are repelled (by each other) no mark for just ionic bonds [0] M4 (i) 4 and both answers must be correct (ii) 535 if incorrect relative formula mass allow mark for correct working accept ecf from c(i) for marks [3] M5 (a) plot correct ( segments) for mark (b) nitrogen + hydrogen ammonia or N H NH 3 all correct for mark (c) largest area labelled nitrogen or shaded for mark Page 40 of 50

41 (d) (i) nitrogen oxygen hydrogen three correct for marks two correct for mark (ii) potassium chloride for mark (e) (i) NH 4 NO 3 = 4 + (4 ) (3 6) = 80 for one mark (ii) ecf (error carried forward from part (i)) look for 8 / 80 for first mark gains mark but 35% (% sign not needed) special case of (4 / = 75%) gains mark gains marks [9] M6 (i) neutralise (the acid) / reduce acidity / because it is alkaline /increases ph for mark (ii) CaO = 56 Ca(OH) = 74 each for mark (iii) mass = /56 gains mark = 3 kg (30 accepted) gains marks (error carried forward from (ii)) 56g 74g g 74/5 6 g ( mark) [5] Page 4 of 50

42 M each for mark [] M8 (a) (3 6) = 00 each for mark (b) M r of CaO = 56 for mark mass required = 60 00/56 for marks = 07 for mark 4 (c) (i) calcium hydroxide (ii) solid [8] M0 (i) 60 ignore units (ii) ignore units (iii) 70 do not carry forward errors [3] M (i) same number of protons and electrons accept equal numbers of protons and electrons do not accept they are neutral Page 4 of 50

43 (ii) same element accept all atoms are potassium same number of protons accept same atomic number accept they all have 9+ different number of neutrons accept different mass numbers do not accept different atomic masses [4] M (a) put on soil or for plants accept land or field or garden or crops or plants accept alternative answer to provide more food for increased population for growth accept to improve plant yield or help them grow accept to replace or add nutrients (not nitrates) or minerals or to make plants grow better or for healthy plants do not accept to make soil fertile or to feed plants (b) (i) (ii) 80 [4] M3 (a) calcium atom loses two electrons accept diagrams with correct labelling (each) fluorine atom gains one electron accept two electrons transfer from a calcium atom to the two fluorine atoms for these first two marks Page 43 of 50

44 forming full (outer) shells of electrons accept forming full (outer) energy levels or noble gas electronic structures do not accept stable unless qualified giving the ions Ca + and F (b) attraction between ions of opposite charges accept electrostatic attraction between ions if candidate mentions sharing or pairing of electrons then no credit if explanation is entirely correct but they state this is called covalent bonding, the maximum mark is four atoms of the same element atomic number is same accept each contains 9 or same number of protons mass numbers differ or each has a different number of neutrons one has 46 neutrons the other has 43 neutrons accept one has three more or less neutrons than the other (c) (i) 349 (ii) 349g UF produces 35g U [] first mark can be awarded if answer is incorrect answer = 75 [] M4 60 ignore units if answer incorrect then ( 56) + (3 6) or + 48 for one mark [] Page 44 of 50

45 M5 (i) convection currents accept a suitable description of convection currents move the Earth s plates accept a suitable description of movement of Earth s plates at plate boundary one plate or a slab of rock can be pushed down forming magma/molten rock accept at subduction zones magma/molten rock is formed deconstructive boundary magma/molten rock rising and cooling at the Earth s surface reforms as part of the plate accept magma/molten rock rising and cooling at the Earth s surface forms igneous rock constructive boundary accept Earth s crust or lithosphere for Earth s surface (ii) isotopes are atoms of the same element do not accept that isotopes have the same atomic number but a different atomic mass 9/the same number of protons 9/the same number of electrons do not penalise for incorrect 0 and neutrons/different numbers of neutrons arithmetic if concept is correct [8] M6 (a) 00 ignore units (3 6) for mark (b) 40 (ecf from part (a) can get marks) for mark Page 45 of 50

46 (c) 05 (ecf from part (b) can get marks) or other correct working for mark (d) gas produced or carbon dioxide / CO produced [7] M7 (i) 60 ignore units ( 56) + (3 6) for mark (ii) 70 for mark allow ecf from part (i) (iii) 700 allow ecf from part (ii) [5] M8 (a) 83 on diagram as Xs / dots or e accept paired or unpaired Page 46 of 50

47 (b) any two from: electrons in highest energy level or electrons in outer shell electrons are delocalised or sea of electrons electrons are free or electrons move around / flow electrons carry charge / current ignore carry electricity [3] M9 (a) 57 correct answer with or without working ( 9 + 9) for mark only allow (9 + 9 =) 38 for mark only ignore units (b) 4 accept answers in the range 4 to 4038 ignore incorrect rounding after correct answer 5 only without working gains mark or 38/57 00 gains mark or (9/57 00 =) to gains mark allow error carried forward from part(a) 38/(a) 00 gains marks if calculated correctly (9/38 00 =) 38 gains mark (c) 09 accept answers in the range 08 to 03 allow error carried forward from part (b) (b)/00 correctly calculated ignore units Page 47 of 50

48 (d) an electron allow electrons allow electron shared / lost for mark apply list principle for additional particles is gained owtte must be linked to electron accept can hold / take in if in correct context eg it can hold another electron (in its outer shell) = marks it can take an electron (from another atom) = marks ignore reference to fluoride ions incorrect number of electrons gained does not gain the second mark [7] M30 (a) 57 correct answer with or without working ( 9 + 9) for mark only allow (9 + 9 =) 38 for mark only ignore units (b) 4 accept answers in the range 4 to 4038 ignore incorrect rounding after correct answer 5 only without working gains mark or 38/57 00 gains mark or (9/57 00 =) to gains mark allow error carried forward from part(a) 38/(a) 00 gains marks if calculated correctly (9/38 00 =) 38 gains mark (c) 09 accept answers in the range 08 to 03 allow error carried forward from part (b) (b)/00 correctly calculated ignore units Page 48 of 50

49 (d) an electron allow electrons allow electron shared / lost for mark apply list principle for additional particles is gained owtte must be linked to electron accept can hold / take in if in correct context eg it can hold another electron (in its outer shell) = marks it can take an electron (from another atom) = marks ignore reference to fluoride ions incorrect number of electrons gained does not gain the second mark [7] Page 49 of 50

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