the Earth formed as a molten ball of rock and minerals the volcanoes released gases that formed the Earth s early atmosphere.

Transcription

1 Q. (a) Scientists have suggested that: the Earth formed as a molten ball of rock and minerals the rock and minerals cooled slowly the surface of the Earth was covered by volcanoes the volcanoes released gases that formed the Earth s early atmosphere. The pie charts show the approximate percentages of gases in the Earth s early atmosphere and in the Earth s atmosphere today. (i) Explain what has happened to most of the water vapour in the Earth s early atmosphere. Give two reasons why the percentage of carbon dioxide in the Earth s early atmosphere decreased Page of 85

2 (b) Scientists have suggested that the Earth consists of a core, mantle and crust. A traditional theory is that the core is made of iron and nickel. A controversial theory is that the core is like a nuclear reactor made of the radioactive elements uranium and plutonium. (i) Why can scientists not prove which theory about the core is correct? () How can the controversial theory be used to explain why the Earth s tectonic plates move? (3) (Total 8 marks) Page 2 of 85

3 Q2. Many human activities result in carbon dioxide emissions. Our carbon footprint is a measure of how much carbon dioxide we each cause to be produced. (a) Why should we be concerned about our carbon footprint? () (b) Most power stations in the UK burn coal. Coal was formed from tree-like plants over millions of years. Suggest why burning wood instead of coal would help to reduce our carbon footprint (3) (Total 4 marks) Page 3 of 85

4 Q3. The Earth is made up of several layers. (a) Draw one straight line from each layer to its correct name. core Layer crust Layer 2 mantle Layer 3 nucleus (3) Page 4 of 85

5 (b) The table shows the main gases in the Earth s atmosphere. Gas Percentage (%) in the atmosphere Nitrogen 78.0 Oxygen 2.0 Argon Carbon dioxide 0.03 Use information in the table to help you to complete the sentences. (i) Draw a ring around the correct answer to complete the sentence The percentage of argon in the Earth s atmosphere is 9.7 % () Complete the sentence. The gas in the Earth s atmosphere that is a compound is.... () (Total 5 marks) Page 5 of 85

6 Q4. The Earth has a layered structure and is surrounded by an atmosphere. (a) Scientists believe that the Earth s atmosphere was formed by volcanoes releasing gases. This early atmosphere was about 95 % carbon dioxide. The composition of the Earth s atmosphere is always changing. (i) The Earth s atmosphere today contains about % carbon dioxide. What happened to most of the carbon dioxide that was in the Earth s early atmosphere? About 60 million years ago a large meteorite hit the Earth. This meteorite heated limestone in the Earth s crust causing the release of large amounts of carbon dioxide. Explain how carbon dioxide is released from limestone. Page 6 of 85

7 (b) The graph shows the percentage of carbon dioxide in the Earth s atmosphere over the last 50 years. Explain, as fully as you can, why we should be concerned about the information displayed on this graph (3) Page 7 of 85

8 (c) Scientists believe that all the continents of the Earth were once joined together. The huge supercontinent was called Pangaea. In 95, Alfred Wegener had an idea that the change shown in the diagram was caused by continental drift. Most scientists could not accept his idea. (i) Suggest why most scientists in 95 could not accept Wegener s idea of continental drift. () Page 8 of 85

9 To help you with this question, the information and diagram from the beginning of the question are reproduced here. The Earth has a layered structure and is surrounded by an atmosphere. Use this information and your knowledge and understanding to explain how continents move. (3) (Total marks) Page 9 of 85

10 Q5. The Earth has a layered structure and is surrounded by an atmosphere. (a) The diagram shows the layers of the Earth. Complete the labels on the diagram. Page 0 of 85

11 (b) The data in the table shows the percentages of the gases in the Earth s atmosphere. Name of gas Percentage (%) of gas Nitrogen 78 Oxygen 2 Other gases Present the data in the table on the grid below. (3) Page of 85

12 (c) Millions of years ago a large meteorite hit the Earth. The meteorite heated limestone in the Earth s crust to a very high temperature. The heat caused calcium carbonate in the limestone to release large amounts of carbon dioxide. Draw a ring round the correct answer to complete each sentence. decomposed. (i) Carbon dioxide was released because the calcium carbonate was evaporated. reduced. () acid rain. More carbon dioxide in the Earth s atmosphere causes global dimming. global warming. () (Total 7 marks) Page 2 of 85

13 Q6. The bar chart shows some of the gases in the atmospheres of Earth today and Mars today. (a) (b) Complete the bar chart to show the percentage of nitrogen in the Earth s atmosphere today. Some scientists suggest that the Earth s early atmosphere was like the atmosphere of Mars today. () (i) There is not much oxygen in the atmosphere of Mars. Suggest why. () The percentage of argon in the Earth s atmosphere today is the same as it was in the Earth s early atmosphere. Suggest why. () (c) Compared with the percentage of carbon dioxide in the Earth s early atmosphere there is not much carbon dioxide in the Earth s atmosphere today. Give one reason for this change () Page 3 of 85

14 (d) Draw a ring around the correct answer to complete the sentence. Some theories suggest that the Earth s early atmosphere was burning fossil fuels. made by the formation of oceans. the eruption of volcanoes. () (Total 5 marks) Q7. The table shows some properties of gases in dry air Gas in dry air Density in kg/m 3 Melting point in C Boiling point in C Percentage (%) in air Nitrogen Oxygen Carbon dioxide Helium Neon Argon Krypton Xenon (a) In 895, Lord Rayleigh isolated nitrogen from dry air by removing the other known gases, oxygen and carbon dioxide. He then discovered that nitrogen from dry air had a different density to pure nitrogen produced from chemical reactions. He concluded that nitrogen extracted from dry air was mixed with another gas. The density of nitrogen extracted from dry air was higher than the density of pure nitrogen. Use the information above to explain why Page 4 of 85

15 (b) Gases from the air are separated to provide raw materials used in many different industrial processes. Steps in dry air separation: Step : Filter to remove solid particles Step 2: Remove carbon dioxide Step 3: Cool the remaining air to 200 C Step 4: Separate by allowing the liquefied gases to warm up. (i) Carbon dioxide is removed before the air is cooled to 200 C. Suggest one reason why. () Which two gases do not condense when the remaining air is cooled to 200 C?...and... () (iii) Two gases in air do not separate completely when the liquefied gases are allowed to warm up. Name these two gases and give a reason for your answer. (Total 6 marks) Page 5 of 85

16 Q8. Venus is often compared to the Earth. The Earth s early atmosphere was mainly carbon dioxide like the atmosphere of Venus today. Atmosphere of Earth today Atmosphere of Venus today Gas Percentage (%) Gas Percentage (%) Nitrogen 78 Nitrogen 3.5 Oxygen 2 Oxygen A trace Carbon dioxide 0.04 Carbon dioxide 96 (a) Give two reasons why the percentage of carbon dioxide decreased in the Earth s early atmosphere (b) In the 950s two scientists, Miller and Urey, investigated the origin of life on Earth. Miller and Urey used the gases that they believed were in the Earth s early atmosphere and used water to represent the oceans. The gases they used were methane (CH 4 ), ammonia (NH 3 ) and hydrogen (H 2 ). A continuous electrical spark was used to simulate lightning storms. After one week the Miller-Urey experiment had produced amino acids. Amino acids are essential to life. The simplest amino acid is glycine (aminoethanoic acid). Page 6 of 85

17 The apparatus used in the Miller-Urey experiment is shown in the diagram. Use the information above and in the diagram to answer these questions. (i) Miller and Urey used methane, ammonia and hydrogen for the Earth s early atmosphere. Suggest why. () The experiment provides only weak evidence of how amino acids formed on Earth. Suggest two reasons why. (Total 5 marks) Page 7 of 85

18 Q9. This is a diagram of the layered structure of the Earth. (a) Draw a line from each layer to the correct name of the layer. Layer Name core Layer A crust Layer B mantle Layer C nucleus (3) Page 8 of 85

19 (b) The Earth s early atmosphere was 96% carbon dioxide. The atmosphere of the Earth today is 0.04% carbon dioxide. The percentage of carbon dioxide in the Earth s atmosphere has changed. Give two reasons why. You should consider: the formation of surface water (oceans) the formation of sedimentary rocks (limestone) (Total 5 marks) Q0. About 3000 million years ago, carbon dioxide was one of the main gases in the Earth s atmosphere. About 400 million years ago, plants and trees grew on most of the land. When the plants and trees died they were covered by sand and slowly decayed to form coal. (a) Describe and explain how the composition of the Earth s atmosphere was changed by the formation of coal (3) Page 9 of 85

20 (b) Today, coal is burned in power stations to release the energy needed by industry. Carbon dioxide, water and sulfur dioxide are produced when this coal is burned. Name three elements that are in this coal (c) In some power stations coal is mixed with calcium carbonate (limestone). The mixture is crushed before it is burned. (i) Many chemical reactions happen when this mixture is burned. The chemical equation represents one of these reactions. Balance the chemical equation. 2CaCO 3 (s) + 2SO 2 (g) + O 2 (g) CaSO 4 (s) + CO 2 (g) () Explain how the use of calcium carbonate in the mixture: increases atmospheric pollution decreases atmospheric pollution. (4) (Total 0 marks) Page 20 of 85

21 Q. The amount of carbon dioxide in the Earth s atmosphere has changed since the Earth was formed. The amount of carbon dioxide continues to change because of human activities. (a) Cement is produced when a mixture of calcium carbonate and clay is heated in a rotary kiln. The fuel mixture is a hydrocarbon and air. Hydrocarbons react with oxygen to produce carbon dioxide. Calcium carbonate decomposes to produce carbon dioxide. (i) Complete each chemical equation by writing the formula of the other product. Hydrocarbons and calcium carbonate contain locked up carbon dioxide. What is locked up carbon dioxide? Page 2 of 85

22 (b) Graph shows how the percentage of carbon dioxide in the atmosphere changed in the last 4500 million years. Use information from Graph to answer these questions. (i) Describe how the percentage of carbon dioxide has changed in the last 4500 million years. Give two reasons why the percentage of carbon dioxide has changed. Page 22 of 85

23 (c) Graph 2 shows how the percentage of carbon dioxide in the atmosphere changed in the last 250 years. Should we be concerned about this change in the percentage of carbon dioxide? Explain your answer (Tota 0 marks) Page 23 of 85

24 Q2. Scientists study the atmosphere on planets and moons in the Solar System to understand how the Earth s atmosphere has changed. (a) Millions of years ago the Earth s atmosphere was probably just like that of Mars today. The table shows data about the atmosphere of Mars and Earth today. Mars today Earth today nitrogen 3% nitrogen 78% oxygen trace oxygen 2% water trace water trace Carbon dioxide 95% Carbon dioxide trace Average surface temperature 23 C Average surface temperature 5 C The percentages of some gases in the Earth s atmosphere of millions of years ago have changed to the percentages in the Earth s atmosphere today. For two of these gases describe how the percentages have changed and suggest what caused this change Page 24 of 85

25 (b) Titan is the largest moon of the planet Saturn. Titan has an atmosphere that contains mainly nitrogen. Methane is the other main gas. Main gases in Titan's atmosphere Percentage (%) Boiling point in C Nitrogen Methane 5 64 Average surface temperature 78 C When it rains on Titan, it rains methane! Use the information above and your knowledge and understanding to explain why (c) Ultraviolet radiation from the Sun produces simple alkenes, such as ethene (C 2 H 4 ) and propene (C 3 H 6 ) from methane in Titan s atmosphere. State the general formula for alkenes.... () (Total 5 marks) Page 25 of 85

26 Q3. Scientists study the atmosphere on planets and moons in the Solar System to understand how the Earth s atmosphere may have evolved. Titan is the largest moon of Saturn. The table shows data about some substances in the atmosphere of Titan. Substance Melting point in C Boiling point in C Nitrogen Methane Argon Hydrogen Carbon monoxide (a) There is no water on Titan. The average surface temperature on Titan is 79 C. Which of the substances in the table would form oceans on Titan? Explain your answer Page 26 of 85

27 (b) Amino acids are essential to life. In the 950s the Miller-Urey experiment showed that simple amino acids, such as glycine (NH 2 CH 2 COOH), could have been produced from the Earth s early atmosphere. The Miller-Urey experiment showed that simple amino acids could be produced by reactions between hydrocarbons, ammonia and water. Explain how the Miller-Urey experiment suggests that reactions between the substances in Titan s atmosphere could also produce simple amino acids (4) (Total 6 marks) Q4. The Earth is almost spherical and is surrounded by an atmosphere. The figure below shows a section of the layered structure of the Earth. (a) In 95 Alfred Wegener put forward his idea of continental drift. (i) Why did most scientists in 95 not accept Wegener s idea of continental drift? () Page 27 of 85

28 Describe how and explain why continental drift takes place. Include the names of X and Y in your answer. (5) (b) The table below shows some properties of gases in the Earth s atmosphere. Gas Melting point in C Boiling point in C Argon Carbon dioxide Helium Neon Nitrogen Oxygen These gases are separated by: removing carbon dioxide cooling the remaining gases to 200 C removing the gases that do not condense allowing the liquefied gases to warm up. (i) Suggest one reason why carbon dioxide is removed before the gases are cooled to 200 C. () Page 28 of 85

29 Draw a ring around one gas that does not condense when the remaining gases are cooled to 200 C. argon neon nitrogen oxygen () (iii) The oxygen separated by this process contains another gas. Name the gas and give a reason for your answer. (Total 0 marks) Q5. Fossil fuels contain carbon and hydrogen. (a) (i) Use the Chemistry Data Sheet to help you to answer this question. Complete the figure below to show the electronic structure of a carbon atom. () Complete the word equation for the oxidation of hydrogen. hydrogen + oxygen... () Page 29 of 85

30 (b) Coal is a fossil fuel. Coal contains the elements hydrogen, sulfur, oxygen and carbon. Name two products of burning coal that have an impact on the environment. What impact does each of the products you named have on the environment? (4) (Total 6 marks) Q6. Some theories suggest that the Earth s early atmosphere was the same as Mars atmosphere today. The table below shows the percentage of four gases in the atmosphere of Mars today and the atmosphere of Earth today. Gases Mars today The atmosphere of Earth today Carbon dioxide 95.00% 0.04% Nitrogen 3.50% 78.00% Argon.00% 0.96% Oxygen 0.50% 2.00% (a) Which one of the gases in the table is a noble gas?... () (b) Draw a ring around the correct answer to complete each sentence. (i) Noble gases are in Group 0 7 () Page 30 of 85

31 Noble gases are slightly reactive. unreactive. very reactive. () (c) The percentage of carbon dioxide in the Earth s early atmosphere was 95.00%. It is 0.04% in the Earth s atmosphere today. (i) Calculate the decrease in the percentage of carbon dioxide in the Earth s atmosphere. Decrease in percentage =...% () Give two reasons for this decrease. (Total 6 marks) Q7. This question is about life, the Earth and its atmosphere. (a) There are many theories about how life was formed on Earth. Suggest one reason why there are many theories () Page 3 of 85

32 (b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. This Earth and its atmosphere today are not like the early Earth and its atmosphere. Describe and explain how the surface of the early Earth and its atmosphere have changed to form the surface of the Earth and its atmosphere today (6) (Total 7 marks) Page 32 of 85

33 Q8. Polymers and fuels can be produced from crude oil and from plants. (a) There are many types of polymer. Each polymer has different properties. (i) Poly(chloroethene) is a polymer produced from crude oil. Why is poly(chloroethene) used for water pipes? Tick ( ) two boxes. The polymer is not biodegradable. The polymer is made from crude oil. The polymer decomposes when heated. The polymer is waterproof. The polymer does not conduct electricity. Some shopping bags are made from a biopolymer. Biopolymers are produced from plants. Suggest one advantage of using a biopolymer. () Page 33 of 85

34 (b) Some plants have seeds that contain vegetable oils. The flow diagram shows how the oil can be extracted. (i) Use the correct word from the box to complete each sentence. burning crushing distilling filtering Oil is released from the seeds by.... Solids are removed from the oil and water by.... Describe how the tap funnel can be used to separate the oil from the water. Page 34 of 85

35 (c) Vegetable oils are used as foods and fuels. (i) Why are vegetable oils important foods and fuels? Tick ( ) one box. They are used as emulsifiers. They have high boiling points. They provide a lot of energy. () Burning fossil fuels made from crude oil increases the overall percentage of carbon dioxide in the atmosphere. Burning biofuels made from vegetable oil does not increase the overall percentage of carbon dioxide in the atmosphere. Explain why. (Total 0 marks) Q9. Two scientists, Miller and Urey, investigated how simple gases that may have been present in the Earth s early atmosphere led to the formation of chemicals such as glycine. Glycine is found in living organisms. The displayed (structural) formula of glycine is: (a) Name three simple gases that could have been present in the Earth s early atmosphere that might combine to form glycine (3) Page 35 of 85

36 (b) Describe the main differences between the Earth s early atmosphere and the atmosphere today (4) (c) Air is a source of some gases used in industrial processes. Name the process used to separate the gases in air. Give the reason why this process can be used to separate the gases (Total 9 marks) Page 36 of 85

37 Q20. Active volcanoes give off gases. Koryaksky volcano, Russia. Photo by Jack Lockwood of the USGS, public domain via wikimedia commons The table shows the percentages of gases a volcano gives off. Name of gas Percentage (%) of gas Carbon dioxide 49 Water vapour 37 Sulfur dioxide 2 Carbon monoxide 2 (a) Scientists use this data to predict what the Earth s early atmosphere was like and how the oceans were formed. Use information from the table to help you answer the following questions. (i) Describe how a gas released from volcanoes caused the oceans to be formed Gases from volcanoes formed the Earth s early atmosphere. Which was the main gas in the Earth s atmosphere billions of years ago?... () (iii) Which two other gases were also present in the Earth s early atmosphere? Page 37 of 85

38 Tick ( ) two boxes. Gas Tick ( ) Ammonia Chlorine Fluorine Methane (b) What are the two main gases in the Earth s atmosphere today? Tick ( ) two boxes. Gas Tick ( ) Chlorine Hydrogen Nitrogen Oxygen (c) (i) Draw a ring around the correct answer in the box to complete the sentence. The amount of carbon dioxide in the atmosphere is increasing. combustion. The main process causing this is condensation. photosynthesis. () Page 38 of 85

39 How is carbon from carbon dioxide locked up in sedimentary rocks? Tick ( ) two boxes. Tick ( ) In calcium carbonate In the mantle In fossil fuels In the Earth s core (Total 0 marks) Q2. The graph shows changes in the percentage of oxygen in the Earth s atmosphere over the last thousand million years. (a) (i) The percentage of oxygen in the atmosphere changed between 700 million years ago and 300 million years ago. How many more times greater was the percentage of oxygen in the atmosphere 300 million years ago compared with 700 million years ago? Answer =... times greater () Page 39 of 85

40 The percentage of oxygen in the atmosphere changed between 700 million years ago and 300 million years ago. Explain why. (iii) Suggest an explanation for the change in the percentage of oxygen in the atmosphere between 300 and 250 million years ago. Page 40 of 85

41 (b) One theory for the origin of life on Earth is the chemosynthesis theory. This theory states that life on Earth began when more and more complex organic molecules and structures were synthesised. After a long time, these molecules and structures became living organisms. Two scientists, Miller and Urey, used the apparatus below to investigate the development of life on Earth. The gases in the reaction chamber were water vapour, methane and hydrogen. When electric sparks were produced in the reaction chamber a mixture of organic compounds was produced. These organic compounds can be combined to make proteins. Does the Miller Urey experiment support the chemosynthesis theory for the origin of life? Explain your answer (Total 7 marks) Page 4 of 85

42 Q22. The diagram shows a section through the Earth and the layer that is above the Earth s surface. (a) Name the parts labelled A, B, C and D, on the diagram. (4) Page 42 of 85

43 (b) The bar chart shows the composition of the atmosphere on Mars. Complete each sentence to give three differences between the composition of the atmospheres on Mars and on Earth. The atmosphere on Mars has a much higher percentage of.... The atmosphere on Mars has a much lower percentage of.... The atmosphere on Mars has no.... (3) (Total 7 marks) Q23. The atmosphere of Mars is different from the atmosphere of Earth. (a) (i) What is the percentage of nitrogen in the Earth s atmosphere today? () Page 43 of 85

44 Table shows the percentages of gases in the atmosphere of Mars. Table Gas Percentage of gases in the atmosphere of Mars (%) Carbon dioxide 95 Nitrogen 3 Oxygen 0.3 Earth s early atmosphere may have been like the atmosphere on Mars. Describe how and why the percentages of carbon dioxide and oxygen in the Earth s atmosphere have changed. (5) Page 44 of 85

45 (b) Table 2 shows the mean surface temperature and percentage of water vapour in the atmosphere of three planets. Table 2 Earth Mars Venus Mean surface temperature in C Percentage (%) of water vapour in atmosphere Suggest why Venus and Mars do not have oceans (Total 8 marks) Q24. (a) The diagram shows a section through the Earth and its atmosphere. Use words from the box to label parts A and B on the diagram. Core Crust Mantle Plate Page 45 of 85

46 (b) Table shows the percentages of gases in the atmospheres of Earth and Mars. Table Gas Percentage of gas (%) Earth Mars Carbon dioxide Nitrogen 78 3 Oxygen Using Table, describe how the atmosphere of the Earth is different from the atmosphere of Mars (c) Table 2 shows the mean surface temperature of three planets. Table 2 Earth Mars Venus Mean surface temperature in C Oceans cover 7% of the Earth s surface. Mars and Venus have water vapour in their atmospheres. Why does the water vapour not form oceans on their surfaces? Mars: Venus: (Total 6 marks) Page 46 of 85

47 Q25. The diagram shows the apparatus used to investigate the percentages of gases in the air. 00 cm 3 of air was measured using Syringe A. The air was passed over the heated copper by pushing the plungers backwards and forwards. The air was passed over the heated copper until the volume of air did not change. A black solid formed on the copper when the air was passed over the copper. (a) (i) Which gas in the air reacted with the copper? () What volume of this gas would you expect to react with copper in the investigation? cm 3 () (iii) Write a word equation for the reaction occurring between copper and the gas () (b) (i) What is the main gas remaining in the apparatus at the end of the investigation? () Name one other gas which will also be present at the end of the investigation. () (Total 5 marks) Page 47 of 85

48 Q26. This question is about the Earth s atmosphere today. (a) The bar chart shows the percentage by mass of the gases in dry air from the atmosphere. Gases (i) What percentage of the atmosphere is gas A?... % () Use gases from the box to answer this question. bromine hydrogen nitrogen oxygen Name gas A and gas B shown on the bar chart. Gas A:... Gas B:... Page 48 of 85

49 (b) The concentration of carbon dioxide in the atmosphere has changed. The graph shows how the concentration of carbon dioxide has changed since 800. Year (i) Describe how the concentration of carbon dioxide has changed since 800. Complete the following sentence. The main process that has caused the change in carbon dioxide is the burning of.... () (Total 6 marks) Q27. This article appeared in a local newspaper. Page 49 of 85

50 (a) (i) Name the environmental effect caused by solid particulates such as soot. () Why is soot produced by cars? () (b) (i) Acid rain damages limestone buildings. Describe the chemical reaction causing this damage. State what happens to the products of the reaction. (3) Suggest why the gardener thought acid rain was causing the damage to his greenhouse. Use your answer to part (b)(i) and information from the article to help you to answer this question. (Total 7 marks) Page 50 of 85

51 Q28. Figure shows the concentration of carbon dioxide in the air from 980 to 200. Figure (a) What is the main cause of the change in carbon dioxide concentration shown in Figure? Year () Page 5 of 85

52 (b) Figure 2 shows part of the Great Barrier Reef. The Great Barrier Reef is in an ocean and is made of coral. Coral is made by tiny living organisms. Figure 2 pniesen/istock/thinkstock Scientists measured the amount of coral on the reef from 980 to 200. By 200 half (50 %) of the coral present in 980 had disappeared from the reef. Suggest why a change in carbon dioxide concentration in the air can affect coral in the marine environment Page 52 of 85

53 Figure 3 has been repeated to help you answer the question. Figure 3 Year (c) (i) Use Figure 3 to estimate the carbon dioxide concentration in parts per million in Estimated carbon dioxide concentration in 2020 =... parts per million. () Page 53 of 85

54 By 200 half (50 %) of the coral present in 980 had disappeared from the reef. Scientists predict that half of the coral remaining in 200 could disappear by Consider the change in the amounts of coral and the carbon dioxide concentration in 980, 200 and Use the data to explain the scientists prediction. (3) (Total 7 marks) Page 54 of 85

55 Q29. Figure shows the concentration of carbon dioxide in the air from 980 to 200. Figure Year (a) Use the correct answer from the box to complete the sentence. burning fossil fuels earthquakes photosynthesis The main reason for the change in carbon dioxide concentration is.... () (b) Scientists estimate that in 2020, the carbon dioxide concentration in parts per million will be 430. Plot this point on the graph. Draw a line of best fit to complete the graph. Page 55 of 85

56 (c) Figure 2 shows part of the Great Barrier Reef. The Great Barrier Reef is in an ocean. The Great Barrier Reef is made of coral. Coral is made by tiny living organisms. Figure 2 pniesen/istock/thinkstock Scientists measured the amount of coral on the reef from 980 to 200. The scientists used the data to predict the amount of coral on the reef in The results are shown in the table below. Year Relative amount of coral Use information from Figure and the table. What conclusion can you make about the change in carbon dioxide concentration in the air and the amount of coral on the reef from 980 to 2020? (Total 5 marks) Page 56 of 85

57 Q30. This question is about air pollutants. (a) Figure shows the level of particulates in the air from 990 to 200. Figure Year (i) Particulates are produced by burning fossil fuels. What are particulates? () Name an environmental effect caused by particulates. () (iii) Suggest two reasons why it is difficult to predict what particulate levels will be in the future. Page 57 of 85

58 (b) Figure 2 shows the concentration of sulfur dioxide in the air from 980 to Figure 2 Year (i) The concentration of sulfur dioxide in the air changed from parts per million in 980 to 4 parts per million in Suggest and explain how this change would have affected the rate of decay of limestone buildings. (3) What can be done at a coal-fired power station to reduce the amount of sulfur dioxide released into the air? () (Total 8 marks) Page 58 of 85

59 Q3. The figure below shows a power station. Fossil fuels are burnt at some power stations. Uli Hamacher/iStock (a) Draw a ring around the correct answer to complete the sentence. Fossil fuels release energy by combustion. decomposition. distillation. () (b) Burning fuels can also release substances which cause an environmental effect. Draw one line from each substance to an environmental effect caused by the substance. Substance Environmental effect Acid rain Carbon dioxide Bioleaching Oxides of nitrogen Global dimming Solid particles Global warming (3) (Total 4 marks) Page 59 of 85

60 M. (a) (i) it = water vapour condensed accept temperature went below 00 C / boiling point of water allow cooled to form liquid / water / rain do not accept evaporated formed the oceans / seas ignore rain accept (water vapour) cooled and formed the ocean / sea for 2 marks any two from: ignore oxygen / nitrogen increased ignore reference to volcanoes / respiration used by (green) plants / algae accept photosynthesis / plants give out oxygen changed into oxygen dissolved in oceans / seas accept (locked up) in shells / skeletons (of animals) (locked up) in carbonates / sedimentary rocks (locked up) in fossil fuels / named fossil fuel 2 (b) (i) cannot get to / reach / drill to / see the core accept the core is (too) far down (into the Earth) / do not know what happens under the crust / Earth s surface accept it is (too) hot / radioactive ignore lack of evidence unqualified any three from: heat / energy released from radioactive decay / processes accept radioactivity / nuclear reactions (causing) convection currents in the mantle 3 [8] Page 60 of 85

61 M2. (a) (thought to cause) global warming / green house (effect) / climate change ignore other consequences of global warming do not accept acid rain / ozone layer / global dimming (b) any three from: replant trees / renewable / sustainable ignore reusable carbon (dioxide) used by trees / photosynthesis accept trees absorb carbon (dioxide) as they grow ignore respiration it is a (continuous / carbon) cycle accept burning wood is carbon neutral or carbon (dioxide) goes back into the air for the second and third bullet points: accept trees use carbon dioxide which is released when (trees / wood are / is) burnt for 2 marks no new carbon (dioxide) is produced or no locked up carbon (dioxide) is released or the carbon (dioxide) was absorbed millions of years ago 3 [4] M3. (a) layer crust extra line from a layer cancels the mark layer 2 mantle layer 3 core (b) (i) 0.97 extra ring drawn cancels the mark carbon dioxide / CO 2 [5] Page 6 of 85

62 calcium carbonate / CaCO 3 M4. (a) (i) any two from: used by plants allow specific plants and algae used for photosynthesis ignore oxygen released / respiration absorbed / dissolved in oceans ignore oceans formed locked up in fossil fuels / limestone / sedimentary rocks 2 decomposed / thermal decomposition do not allow reaction with oxygen accept quicklime / calcium oxide produced CaCO 3 CaO + CO 2 gains 2 marks (b) increasing (CO 2 or global warming) more rapid increase recently carbon dioxide causes global warming accept greenhouse gas or climate change / sea level rising or ice caps melting do not accept ozone layer or acid rain or global dimming (c) (i) any one from: Wegener had no evidence / proof accept movement too slow to measure other scientists had different ideas / views accept continents / plates fixed or land bridge did not respect Wegener as a scientist / geologist Page 62 of 85

63 any three from: plates (move) ignore continents heat energy / radioactivity (causes) convection currents in mantle 3 [] M5. (a) crust ignore Earth s core ignore inner and/or outer (b) bar chart all heights are correct accept correctly plotted points all labels are correct for nitrogen, oxygen and other / argon (c) (i) decomposed global warming [7] M6. (a) bar drawn correctly (%) (b) (i) (Mars has) no (green / living) plants / trees (argon) is unreactive / inert accept argon is a noble gas ignore it is in Group 0 Page 63 of 85

64 (c) (the amount of carbon dioxide has decreased because it has been) absorbed / used by (green / living) plants / trees or used for photosynthesis accept dissolved / absorbed by oceans or locked up in fossil fuels / carbonate rocks (d) the eruption of volcanoes [5] M7. (a) because the nitrogen from dry air contained noble/group 0 gases or ignore other gases (because the nitrogen from dry air) contained argon / krypton / xenon ignore helium and neon and three / some of these gases, (argon, krypton, xenon) have a greater density than nitrogen ignore helium and neon or and argon / krypton / xenon has a greater density than nitrogen (b) (i) carbon dioxide would form / is a solid accept carbon dioxide freezes or its freezing point is > 200 C ignore melting point or (solid) carbon dioxide would block pipes helium (and) neon both needed for mark accept He and Ne (iii) argon (and) oxygen accept Ar and O 2 because there is only a difference of 3 C in their boiling points accept because they have boiling points that are almost the same [6] Page 64 of 85

65 M8. (a) any two from: carbon dioxide dissolves in water/oceans marine organisms use (dissolved) carbon dioxide to form their shells/ skeletons or limestone was formed from the shells/skeleton of marine organisms accept carbon dioxide became locked up in sedimentary rocks/carbonates/limestone or precipitation or formation of insoluble carbonates plants / algae photosynthesise/ absorb/use carbon dioxide accept remains of plants/algae/ marine organisms contain locked up carbon dioxide/carbon in the form of fossil fuels do not accept plants use carbon dioxide for respiration 2 (b) (i) because these gases/molecules contain the elements / atoms in amino acids or the gases / they contain carbon, hydrogen and nitrogen ignore oxygen ignore small-scale / timescale ignore references to water/oceans or other theories any two from: nobody knows what was in the Earth s early atmosphere accept these gases / hydrogen / methane / ammonia may not have been in the Earth s early atmosphere accept carbon dioxide / nitrogen may have been in the Earth s early atmosphere accept reference to Venus present atmosphere ignore concentration of gases there may not have been (continuous) lightning Miller and Urey selected only the gases needed to produce amino acids 2 [5] M9. (a) A core B mantle C crust Page 65 of 85

66 (b) any two from: carbon dioxide dissolves / absorbs in water / oceans allow reacts with water plants / algae photosynthesise / absorb / use carbon dioxide accept remains of plants / algae / marine organisms contain locked up carbon dioxide / carbon in the form of fossil fuels do not accept plants use carbon dioxide for respiration marine organisms use (dissolved) carbon dioxide to form their shells / skeletons or limestone was formed from the shells / skeletons of marine organisms accept carbon dioxide became locked up in sedimentary rocks / carbonates / limestone or precipitation or formation of insoluble carbonates 2 [5] M0. (a) carbon dioxide decreased (by plants / trees) allow plants / trees absorbed carbon dioxide oxygen increased (by plants / trees) allow plants / trees released oxygen if neither of these marks awarded allow plants / trees photosynthesise for mark because coal locks up / traps / stores carbon dioxide / carbon allow trees locked up carbon dioxide / carbon (b) carbon / C hydrogen / H sulfur / S all 3 correct 2 marks or 2 correct mark allow H 2 ignore oxygen 2 (c) (i) 2 2 balancing must be correct do not accept changed formulae Page 66 of 85

67 increases atmospheric pollution carbon dioxide / CO 2 released from the (thermal) decomposition of calcium carbonate or accept causes global warming or CO 2 is a greenhouse gas description of this decomposition or equation ignore sulfur dioxide and effects in this part decreases atmospheric pollution sulfur dioxide / SO 2 is removed accept less acid rain produced by reaction with calcium oxide or calcium carbonate accept neutralisation or forms calcium sulfate [0] M. (a) (i) H 2 O must be formula CaO must be formula carbon dioxide from the air / (Earth s early) atmosphere it = carbon (dioxide) accept carbon dioxide from millions of years ago formed (sedimentary) rocks or fossil fuels ignore trapped / stored (b) (i) decreases rapidly at first it = carbon (dioxide) then slowly or levels off allow both marks if the description is correct using either rapidly or slowly allow correct use of figures for either marking point if no other mark awarded, allow CO 2 decreased for mark Page 67 of 85

68 any two from: it = carbon (dioxide) accept photosynthesis used by plants dissolved in oceans locked up in fossil fuels or formed fossil fuels locked up in rocks or formed rocks 2 (c) (yes) it = percentage of carbon (dioxide) ignore yes or no because the percentage of carbon dioxide is increasing which causes global warming (to increase) allow (carbon dioxide) causes greenhouse effect/climate change or (no) because the percentage of carbon dioxide is low () compared to millions of years ago () allow global warming can be caused by other factors (e.g. Sun / water vapour / methane) [0] Page 68 of 85

69 M2. (a) any two from: asks for cause therefore no marks for just describing the change must link reason to a correct change in a gas carbon dioxide has decreased due to: accept idea of used to indicate a decrease plants / microorganisms / bacteria / vegetation / trees photosynthesis ignore respiration locked up in (sedimentary) rocks / carbonates / fossil fuels dissolved in oceans ignore volcanoes oxygen has increased due to: accept idea of given out / produced plants / bacteria / microorganisms / vegetation / trees photosynthesis ignore respiration nitrogen increased due to: accept idea of given out / produced ammonia reacted with oxygen bacteria / micro organisms ignore (increase in) use of fossil fuels / deforestation 2 (b) (because methane s) boiling point is greater than the average / surface temperature or Titan s (average / surface) temperature is below methane s boiling point ignore references to nitrogen or water any methane that evaporates will condense accept boils for evaporates accept cooling and produce rain for condensing (c) C n H 2n [5] M3. (a) methane Page 69 of 85

70 because at the surface temperature of 79 C only methane has melted but has not boiled accept a correct explanation using the boiling points (and melting points) of the gases or methane is a liquid and all the others are gases (b) CH 4 is a hydrocarbon or methane / carbon monoxide contains carbon or carbon monoxide + hydrogen hydrocarbon nitrogen and hydrogen are present in Titan s atmosphere or nitrogen + hydrogen ammonia carbon monoxide contains oxygen or carbon monoxide + hydrogen / methane water amino acids contain carbon, hydrogen, nitrogen + oxygen or amino acids can be made from (methane), hydrogen, carbon monoxide and nitrogen OR lightning / ultraviolet / electrical discharge / high energy needed for reaction [6] M4. (a) (i) Wegener / they could not explain how continents could move allow not enough or no evidence or no proof (of movement) ignore status / technology because the (Earth s) crust (is divided into tectonic) plates the heat (released) from radioactive processes causes convection currents in the mantle (that move the tectonic plates) (b) (i) forms a solid or freezes accept would block pipes neon Page 70 of 85

71 (iii) argon because the boiling points are almost the same or only 3 degrees different do not allow reference to melting points [0] M5. (a) (i) 2,4 drawn (as dots / crosses / e ) Water (vapour) / steam allow hydrogen oxide / H 2 O do not accept hydroxide (b) any two pairs from: carbon dioxide () causes global warming () allow greenhouse effect / climate change / sea level rise / melting of polar ice caps or carbon (particles) / soot () allow particulates causes global dimming () allow blocks out sunlight / smog / prevents plant growth / causes breathing difficulties or carbon monoxide () is toxic () or sulfur dioxide () causes acid rain () allow kills plants / erosion / acidifies water 4 [6] M6. (a) argon / Ar (b) (i) 0 Page 7 of 85

72 unreactive (c) (i) 94.96(%) any two from: plants or photosynthesis absorbed in oceans / seas allow oceans store or take in or dissolve carbon dioxide locked up in (sedimentary) rocks locked up in fossil fuels 2 [6] M7. (a) any one from: not enough evidence or proof allow no evidence or no proof (life and the Earth were created) billions of years ago allow a long time ago ignore different beliefs or no one was there. Page 72 of 85

73 (b) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also refer to the information in the Marking Guidance and apply a best fit approach to the marking. 0 marks No relevant content Level ( 2 marks) Statements based on diagrams Level 2 (3 4 marks) Description of how one change occurred Level 3 (5 6 marks) Descriptions of how at least two changes occurred Examples of chemistry points made in the response could include: Main changes oxygen increased because plants / algae developed and used carbon dioxide for photosynthesis / growth producing oxygen; carbon dioxide decreased because of this carbon dioxide decreased because oceans formed and dissolved / absorbed carbon dioxide; carbon dioxide became locked up in sedimentary / carbonate rocks and / or fossil fuels oceans formed because the Earth / water vapour cooled and water vapour in the atmosphere condensed continents formed because the Earth cooled forming a supercontinent / Pangaea which formed the separate continents volcanoes reduced because the Earth cooled forming a crust. Other changes nitrogen has formed because ammonia in the Earth s early atmosphere reacted with oxygen / denitrifying bacteria. 6 [7] M8. (a) (i) the polymer is not biodegradable the polymer is waterproof any one from: made from a renewable / sustainable resource is biodegradable ignore releases less carbon dioxide allow decomposes. Page 73 of 85

74 (b) (i) crushing in the correct order filtering open the tap to allow only water to flow out or close the tap to leave the oil in the funnel allow close tap then allow oil to flow out into a separate container (c) (i) They provide a lot of energy because the vegetable / plant absorbs / uses carbon dioxide which is released when the biofuel burns second marking point is dependent on first marking point allow a fossil fuel releases locked up carbon dioxide / carbon if no other mark awarded allow carbon neutral for one mark [0] Page 74 of 85

75 M9. (a) if only formula given it must be correct any three from: ammonia accept NH 3 methane accept CH 4 hydrogen accept H 2 allow ethane / butane / propane water vapour accept H 2 O vapour / steam carbon dioxide accept CO 2 carbon monoxide accept CO allow oxygen / O 2 allow nitrogen / N 2 ignore nitrogen oxide ignore carbon 3 (b) (in atmosphere today) ignore references to water vapour allow converse (much) less carbon dioxide / CO 2 allow carbon dioxide was the main gas (in Earth s early atmosphere) more nitrogen / N 2 allow nitrogen is now the main gas (in the atmosphere today) or nitrogen is now 78 80% more oxygen / O 2 no ammonia / NH 3 or less methane / CH 4 or more argon / Ar or more noble gases allow less ammonia / NH 3 Page 75 of 85

76 (c) (fractional) distillation gases have different boiling points allow gases condense at different temperatures ignore condensing points / levels ignore evaporating points / levels [9] M20. (a) (i) water vapour allow steam condensed allow cooled to form a liquid / water second marking point can only be awarded if first marking point correct carbon dioxide allow CO 2 C and O must be upper case numbers in formulae must be subscript do not accept carbon (mon)oxide / CO (iii) ammonia methane (b) nitrogen oxygen (c) (i) combustion in calcium carbonate in fossil fuels [0] Page 76 of 85

77 M2. (a) (i) 2 (oxygen) produced by algae / plants during photosynthesis (iii) catastrophe / volcano / asteroid destroyed most algae / plants dependent on first marking point (b) gives some support since showed that organic compounds might have been formed in early atmosphere allow yes since it showed organic compounds formed but no evidence of structures / living organisms [7] M22. (a) A core ignore references to inner and outer throughout B atmosphere / lithosphere C crust D mantle allow magma (b) carbon dioxide / noble gas / named noble gas accept CO 2 for carbon dioxide accept correct symbol for noble gases nitrogen accept N 2 Page 77 of 85

78 oxygen / water vapour accept O 2 / H 2 O [7] M23. (a) (i) 80(%) allow answers in range 78 80(%) any five from: max 4 marks if no reference to oxygen ignore changes due to combustion of fossil fuels (green) plants / algae photosynthesise take in carbon dioxide (for photosynthesis) release oxygen (in photosynthesis) do not accept for / in respiration accept carbon dioxide has decreased and oxygen has increased for mark carbon dioxide dissolved in oceans accept oceans act as reservoir carbon dioxide locked up in (sedimentary) rocks / carbonates / limestone carbon dioxide locked up in fossil fuels allow locked up in biomass 5 (b) any two from: on Mars the temperature is below freezing point of water / 0 C allow water is frozen / ice on Mars on Venus the temperature is above boiling point of water / 00 C allow water is a gas / steam or has boiled / evaporated on Venus not enough water vapour (in atmosphere) on Venus ignore references to water vapour on Mars 2 [8] M24. (a) A = mantle B = core ignore inner / outer Page 78 of 85

79 (b) any two from: (Earth has) ignore figures unless qualified allow converse responses smaller percentage carbon dioxide allow less larger percentage nitrogen allow more larger percentage oxygen allow more 2 (c) (Mars) temperature below freezing point of water allow too cold (for liquid water to form) allow water will freeze or ice will form (Venus) temperature above boiling point of water allow too hot (for liquid water to form) allow water would boil or would be steam / gas if no other mark awarded allow one mark for not enough water vapour [6] M25. (a) (i) oxygen allow O 2 must have uppercase O and subscript 2 ignore O 20 (cm 3 ) allow 8 22 (cm 3 ) (iii) copper + oxygen copper oxide ignore any attempts at balancing words take precedence reactants in either order ignore di, tri etc allow Cu for Copper allow O 2 for Oxygen allow CuO for copper oxide (b) (i) nitrogen allow N 2 must have uppercase N and subscript 2 ignore N Page 79 of 85

80 any one from: carbon dioxide allow CO 2 must have uppercase letters and subscript 2 argon accept named noble gas or correct symbol allow Ar do not allow Ar 2 water vapour ignore steam allow nitrogen / N 2 if not given in (b)(i) [5] M26. (a) (i) 78 % A nitrogen allow N 2 N must be uppercase and 2 must be subscript ignore N B oxygen allow O 2 O must be uppercase and 2 must be subscript ignore O (b) (i) any two from: level up to 900 (allow 890 to 90) increasing from 900 to today (allow 890 to 90) allow increased by 90 (ppm), allow answers in the range increased more rapidly in last 50 years if no other marks gained allow mark for it has increased 2 (fossil) fuels accept coal / oil / (natural) gas / peat allow petrol / diesel / methane [6] Page 80 of 85

81 M27. (a) (i) global dimming allow smog incomplete / partial combustion (of hydrocarbon fuels) allow description eg too little oxygen / O 2 / air. (b) (i) Any 3 from: ignore name of acid ignore references to limestone / calcium carbonate dissolving limestone is (mainly) calcium carbonate allow correct formula, CaCO 3 (calcium / metal) carbonate reacts with acids ignore limestone reacts with acids carbon dioxide (escapes into the atmosphere) soluble salt is formed allow salt dissolves or salt washed away 3 (polycarbonates) contain carbonate allow (windows) made of polycarbonate (so) could react in a similar way to limestone [7] M28. (a) burning of fossil fuels accept burning of a named fossil fuel (b) Change: carbon dioxide dissolves / is absorbed by oceans / water accept ocean acts as a reservoir / store Effect: increases acidity of water ignore references to acid rain accept as alternative approach: change: global warming / greenhouse gas effect: leads to increase in ocean / water temperature Page 8 of 85