Q1.
(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.
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(2)
(ii)
Give two reasons why the percentage of carbon dioxide in the Earth’s early
atmosphere decreased.
1 ............................................................................................................
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2 ............................................................................................................
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(2)
Page 1 of 85
(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?
...............................................................................................................
...............................................................................................................
(1)
(ii)
How can the ‘controversial’ theory be used to explain why the Earth’s tectonic plates
move?
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(3)
(Total 8 marks)
Page 2 of 85
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?
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(1)
(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.
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(3)
(Total 4 marks)
Page 3 of 85
Q3.
The Earth is made up of several layers.
(a)
Draw one straight line from each layer to its correct name.
core
Layer 1
crust
Layer 2
mantle
Layer 3
nucleus
(3)
Page 4 of 85
(b)
The table shows the main gases in the Earth’s atmosphere.
Gas
Percentage (%) in the
atmosphere
Nitrogen
78.0
Oxygen
21.0
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.
0.97
The percentage of argon in the Earth’s atmosphere is
9.7
%.
97.0
(1)
(ii)
Complete the sentence.
The gas in the Earth’s atmosphere that
is a compound is ........................................................ .
(1)
(Total 5 marks)
Page 5 of 85
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 0.035 % carbon dioxide.
What happened to most of the carbon dioxide that was in the Earth’s early
atmosphere?
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(2)
(ii)
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.
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(2)
Page 6 of 85
(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.
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(3)
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(c)
Scientists believe that all the continents of the Earth were once joined together.
The huge ‘supercontinent’ was called Pangaea.
In 1915, 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 1915 could not accept Wegener’s idea of continental drift.
...............................................................................................................
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(1)
Page 8 of 85
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.
(ii)
Use this information and your knowledge and understanding to explain how
continents move.
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(3)
(Total 11 marks)
Page 9 of 85
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.
(2)
Page 10 of 85
(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
21
Other gases
1
Present the data in the table on the grid below.
(3)
Page 11 of 85
(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.
(1)
acid rain.
(ii)
More carbon dioxide in the Earth’s atmosphere causes
global dimming.
global warming.
(1)
(Total 7 marks)
Page 12 of 85
Q6.
The bar chart shows some of the gases in the atmospheres of Earth today and Mars today.
(a)
Complete the bar chart to show the percentage of nitrogen in the Earth’s atmosphere
today.
(1)
(b)
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.
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(1)
(ii)
The percentage of argon in the Earth’s atmosphere today is the same as it was in the
Earth’s early atmosphere.
Suggest why.
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(1)
(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.
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(1)
Page 13 of 85
(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.
(1)
(Total 5 marks)
Q7.
The table shows some properties of gases in dry air
Gas in dry air
Density in
kg/m3
Melting point
in °C
Boiling point
in °C
Percentage
(%) in air
Nitrogen
1.2506
–210
–196
78.08
Oxygen
1.4290
–219
–183
20.95
Carbon dioxide
1.977
–57
–57
0.033
Helium
0.1785
–272
–269
0.00052
Neon
0.8999
–249
–246
0.0019
Argon
1.7837
–189
–186
0.934
Krypton
3.74
–157
–153
0.00011
Xenon
5.86
–112
–108
0.0000087
(a)
In 1895, 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.
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(2)
Page 14 of 85
(b)
Gases from the air are separated to provide raw materials used in many different industrial
processes.
Steps in dry air separation:
Step 1: 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.
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(1)
(ii)
Which two gases do not condense when the remaining air is cooled to –200 °C?
...........................................and ...........................................
(1)
(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.
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(2)
(Total 6 marks)
Page 15 of 85
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
Gas
Gas
Percentage (%)
Nitrogen
78
Nitrogen
3.5
Oxygen
21
Oxygen
A trace
Carbon dioxide
(a)
Percentage (%)
Atmosphere of Venus today
0.04
Carbon dioxide
96
Give two reasons why the percentage of carbon dioxide decreased in the Earth’s early
atmosphere.
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(2)
(b)
In the 1950s 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 (CH4), ammonia (NH3) and hydrogen (H2).
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 16 of 85
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.
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(1)
(ii)
The experiment provides only weak evidence of how amino acids formed on Earth.
Suggest two reasons why.
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(2)
(Total 5 marks)
Page 17 of 85
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 18 of 85
(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).
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(2)
(Total 5 marks)
Q10.
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.
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(3)
Page 19 of 85
(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.
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(2)
(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.
2CaCO3
+
2SO2(g)
+
O2(g)
→
(s)
………
CaSO4
+
………
CO2(g)
(s)
(1)
(ii)
Explain how the use of calcium carbonate in the mixture:
increases atmospheric pollution
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decreases atmospheric pollution.
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(4)
(Total 10 marks)
Page 20 of 85
Q11.
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.
(2)
(ii)
Hydrocarbons and calcium carbonate contain locked up carbon dioxide.
What is locked up carbon dioxide?
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(2)
Page 21 of 85
(b)
Graph 1 shows how the percentage of carbon dioxide in the atmosphere changed in the
last 4500 million years.
Use information from Graph 1 to answer these questions.
(i)
Describe how the percentage of carbon dioxide has changed in the last 4500 million
years.
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(2)
(ii)
Give two reasons why the percentage of carbon dioxide has changed.
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(2)
Page 22 of 85
(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.
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(2)
(Tota 10 marks)
Page 23 of 85
Q12.
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
21%
water
trace
water
trace
Carbon dioxide
95%
Carbon dioxide
trace
Average surface
temperature −23°C
Average surface
temperature 15°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.
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(2)
Page 24 of 85
(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
95
−196
Methane
5
−164
Average surface
temperature −178°C
When it rains on Titan, it rains methane!
Use the information above and your knowledge and understanding to explain why.
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(2)
(c)
Ultraviolet radiation from the Sun produces simple alkenes, such as ethene (C2H4) and
propene (C3H6) from methane in Titan’s atmosphere.
State the general formula for alkenes.
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(1)
(Total 5 marks)
Page 25 of 85
Q13.
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.
Melting point
in °C
Boiling point
in °C
Nitrogen
–210
–196
Methane
–183
–164
Argon
–189
–186
Hydrogen
–259
–253
Carbon monoxide
–205
–192
Substance
(a)
There is no water on Titan. The average surface temperature on Titan is –179 °C.
Which of the substances in the table would form oceans on Titan?
Explain your answer.
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(2)
Page 26 of 85
(b)
Amino acids are essential to life.
In the 1950s the Miller-Urey experiment showed that simple amino acids, such as glycine
(NH2CH2COOH), 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.
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(4)
(Total 6 marks)
Q14.
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 1915 Alfred Wegener put forward his idea of continental drift.
(i)
Why did most scientists in 1915 not accept Wegener’s idea of continental drift?
...............................................................................................................
...............................................................................................................
(1)
Page 27 of 85
(ii)
Describe how and explain why continental drift takes place.
Include the names of X and Y in your answer.
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(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
–189
–186
Carbon dioxide
–78
–78
Helium
–272
–269
Neon
–249
–246
Nitrogen
–210
–196
Oxygen
–219
–183
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.
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(1)
Page 28 of 85
(ii)
Draw a ring around one gas that does not condense when the remaining gases are
cooled to –200 °C.
argon
neon
nitrogen
oxygen
(1)
(iii)
The oxygen separated by this process contains another gas.
Name the gas and give a reason for your answer.
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(2)
(Total 10 marks)
Q15.
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.
(1)
(ii)
Complete the word equation for the oxidation of hydrogen.
hydrogen
+
oxygen
...........................................
(1)
Page 29 of 85
(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?
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(4)
(Total 6 marks)
Q16.
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.
The atmosphere of
Gases
Mars today
Earth today
95.00%
0.04%
Nitrogen
3.50%
78.00%
Argon
1.00%
0.96%
Oxygen
0.50%
21.00%
Carbon dioxide
(a)
Which one of the gases in the table is a noble gas?
........................................................................................................................
(1)
(b)
Draw a ring around the correct answer to complete each sentence.
0
(i)
Noble gases are in Group
1
7
(1)
Page 30 of 85
slightly reactive.
(ii)
Noble gases are
unreactive.
very reactive.
(1)
(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.
...............................................................................................................
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Decrease in percentage = ..............................%
(1)
(ii)
Give two reasons for this decrease.
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(2)
(Total 6 marks)
Q17.
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.
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(1)
Page 31 of 85
(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.
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(6)
(Total 7 marks)
Page 32 of 85
Q18.
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.
(2)
(ii)
Some shopping bags are made from a biopolymer.
Biopolymers are produced from plants.
Suggest one advantage of using a biopolymer.
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(1)
Page 33 of 85
(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
.................................................. .
(2)
(ii)
Describe how the tap funnel can be used to separate the oil from the water.
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(2)
Page 34 of 85
(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.
(1)
(ii)
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.
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(2)
(Total 10 marks)
Q19.
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.
1 ..........................................................................................
2 ..........................................................................................
3 ..........................................................................................
(3)
Page 35 of 85
(b)
Describe the main differences between the Earth’s early atmosphere and the atmosphere
today.
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(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.
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(2)
(Total 9 marks)
Page 36 of 85
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.
(a)
Name of gas
Percentage (%) of gas
Carbon dioxide
49
Water vapour
37
Sulfur dioxide
12
Carbon monoxide
2
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.
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(2)
(ii)
Gases from volcanoes formed the Earth’s early atmosphere.
Which was the main gas in the Earth’s atmosphere billions of years ago?
........................................................................................................................
(1)
(iii)
Which two other gases were also present in the Earth’s early atmosphere?
Page 37 of 85
Tick ( ) two boxes.
Gas
Tick ( )
Ammonia
Chlorine
Fluorine
Methane
(2)
(b)
What are the two main gases in the Earth’s atmosphere today?
Tick ( ) two boxes.
Gas
Tick ( )
Chlorine
Hydrogen
Nitrogen
Oxygen
(2)
(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.
(1)
Page 38 of 85
(ii)
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
(2)
(Total 10 marks)
Q21.
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
(1)
Page 39 of 85
(ii)
The percentage of oxygen in the atmosphere changed between 700 million years ago
and 300 million years ago.
Explain why.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(iii)
Suggest an explanation for the change in the percentage of oxygen in the
atmosphere between 300 and 250 million years ago.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
Page 40 of 85
(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.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 7 marks)
Page 41 of 85
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
(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?
...............................................................................................................
(1)
Page 43 of 85
(ii)
Table 1 shows the percentages of gases in the atmosphere of Mars.
Table 1
Gas
Percentage of gases in the
atmosphere of Mars (%)
Carbon dioxide
95
Nitrogen
3
Oxygen
0.13
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
(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
20
-23
460
Percentage (%) of water
vapour in atmosphere
0.4
0.002
0.0002
Suggest why Venus and Mars do not have oceans.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(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
(2)
Page 45 of 85
(b)
Table 1 shows the percentages of gases in the atmospheres of Earth and Mars.
Table 1
Percentage of gas (%)
Gas
Earth
Mars
0.04
Carbon dioxide
95
Nitrogen
78
3
Oxygen
21
0.13
Using Table 1, describe how the atmosphere of the Earth is different from the atmosphere
of Mars.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(c)
Table 2 shows the mean surface temperature of three planets.
Table 2
Mean surface temperature in°C
Earth
Mars
Venus
20
-23
460
Oceans cover 71% 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: ............................................................................................................
........................................................................................................................
(2)
(Total 6 marks)
Page 46 of 85
Q25.
The diagram shows the apparatus used to investigate the percentages of gases in the air.
100 cm3 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?
...............................................................................................................
(1)
(ii)
What volume of this gas would you expect to react with copper in the investigation?
............................................................................................................... cm3
(1)
(iii)
Write a word equation for the reaction occurring between copper and the gas.
................................ +
................................ →
................................
(1)
(b)
(i)
What is the main gas remaining in the apparatus at the end of the investigation?
...............................................................................................................
(1)
(ii)
Name one other gas which will also be present at the end of the investigation.
...............................................................................................................
(1)
(Total 5 marks)
Page 47 of 85
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? ........................................ %
(1)
(ii)
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: ......................................................................
(2)
Page 48 of 85
(b)
The concentration of carbon dioxide in the atmosphere has changed.
The graph shows how the concentration of carbon dioxide has changed since 1800.
Year
(i)
Describe how the concentration of carbon dioxide has changed since 1800.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(ii)
Complete the following sentence.
The main process that has caused the change in carbon dioxide is the burning
of ..................................................................................... .
(1)
(Total 6 marks)
Q27.
This article appeared in a local newspaper.
Page 49 of 85
(a)
(i)
Name the environmental effect caused by solid particulates such as soot.
...............................................................................................................
(1)
(ii)
Why is soot produced by cars?
...............................................................................................................
...............................................................................................................
(1)
(b)
(i)
Acid rain damages limestone buildings.
Describe the chemical reaction causing this damage.
State what happens to the products of the reaction.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(ii)
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.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(Total 7 marks)
Page 50 of 85
Q28.
Figure 1 shows the concentration of carbon dioxide in the air from 1980 to 2010.
Figure 1
Year
(a)
What is the main cause of the change in carbon dioxide concentration shown in Figure 1?
........................................................................................................................
........................................................................................................................
(1)
Page 51 of 85
(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 1980 to 2010.
By 2010 half (50 %) of the coral present in 1980 had disappeared from the reef.
Suggest why a change in carbon dioxide concentration in the air can affect coral in the
marine environment.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
Page 52 of 85
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
2020.
Estimated carbon dioxide concentration in 2020 = ................................ parts per
million.
(1)
Page 53 of 85
(ii)
By 2010 half (50 %) of the coral present in 1980 had disappeared from the reef.
Scientists predict that half of the coral remaining in 2010 could disappear by 2020.
Consider the change in the amounts of coral and the carbon dioxide concentration in
1980, 2010 and 2020.
Use the data to explain the scientists’ prediction.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(Total 7 marks)
Page 54 of 85
Q29.
Figure 1 shows the concentration of carbon dioxide in the air from 1980 to 2010.
Figure 1
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
................................................................................................. .
(1)
(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.
(2)
Page 55 of 85
(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 1980 to 2010.
The scientists used the data to predict the amount of coral on the reef in 2020.
The results are shown in the table below.
Year
Relative amount of coral
1980
100
2010
50
2020
25
Use information from Figure 1 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 1980 to 2020?
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 5 marks)
Page 56 of 85
Q30.
This question is about air pollutants.
(a)
Figure 1 shows the level of particulates in the air from 1990 to 2010.
Figure 1
Year
(i)
Particulates are produced by burning fossil fuels.
What are particulates?
...............................................................................................................
(1)
(ii)
Name an environmental effect caused by particulates.
...............................................................................................................
(1)
(iii)
Suggest two reasons why it is difficult to predict what particulate levels will be in the
future.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
Page 57 of 85
(b)
Figure 2 shows the concentration of sulfur dioxide in the air from 1980 to 2005.
Figure 2
Year
(i)
The concentration of sulfur dioxide in the air changed from 11 parts per million in
1980 to 4 parts per million in 2005.
Suggest and explain how this change would have affected the rate of decay of
limestone buildings.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(ii)
What can be done at a coal-fired power station to reduce the amount of sulfur dioxide
released into the air?
...............................................................................................................
...............................................................................................................
(1)
(Total 8 marks)
Page 58 of 85
Q31.
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.
(1)
(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
M1.
(a)
(i)
it = water vapour
condensed
accept temperature went below 100°C / boiling point of water
allow cooled to form liquid / water / rain
do not accept evaporated
1
formed the oceans / seas
ignore rain
accept (water vapour) cooled and formed the ocean / sea for 2
marks
1
(ii)
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
1
(ii)
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
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
1
(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 1 – crust
extra line from a layer cancels the mark
1
layer 2 – mantle
1
layer 3 – core
1
(b)
(i)
0.97
extra ring drawn cancels the mark
1
(ii)
carbon dioxide / CO2
1
[5]
Page 61 of 85
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
(ii)
calcium carbonate / CaCO3
1
decomposed / thermal decomposition
do not allow reaction with oxygen
accept quicklime / calcium oxide produced
CaCO3→ CaO + CO2 gains 2 marks
1
(b)
increasing (CO2 or global warming)
1
more rapid increase recently
1
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
1
(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
1
Page 62 of 85
(ii)
any three from:
•
plates (move)
ignore continents
•
heat energy / radioactivity (causes)
•
convection currents
•
in mantle
3
[11]
M5.
(a)
crust
ignore Earth’s
1
core
ignore inner and/or outer
1
(b)
bar chart
1
all heights are correct
accept correctly plotted points
1
all labels are correct for nitrogen, oxygen and other / argon
1
(c)
(i)
decomposed
1
(ii)
global warming
1
[7]
M6.
(a)
bar drawn correctly 78 – 80 (%)
1
(b)
(i)
(Mars has) no (green / living) plants / trees
1
(ii)
(argon) is unreactive / inert
accept argon is a noble gas
ignore it is in Group 0
1
Page 63 of 85
(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
1
(d)
the eruption of volcanoes
1
[5]
M7.
(a)
because the nitrogen from dry air contained noble/Group 0 gases
ignore other gases
or
(because the nitrogen from dry air) contained argon / krypton / xenon
ignore helium and neon
1
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
1
(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
1
(ii)
helium (and) neon
both needed for 1 mark
accept He and Ne
1
(iii)
argon (and) oxygen
accept Ar and O2
1
because there is only a difference of 3°C in their boiling points
accept because they have boiling points that are almost the same
1
[6]
Page 64 of 85
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
1
(ii)
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
1
B – mantle
1
C – crust
1
Page 65 of 85
(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]
M10.
(a)
carbon dioxide decreased (by plants / trees)
allow plants / trees absorbed carbon dioxide
1
oxygen increased (by plants / trees)
allow plants / trees released oxygen
if neither of these marks awarded
allow plants / trees
photosynthesise for 1 mark
1
because coal ‘locks up’ / traps / stores carbon dioxide / carbon
allow trees ‘locked up’ carbon dioxide / carbon
1
(b)
carbon / C
hydrogen / H
sulfur / S
all 3 correct 2 marks
1 or 2 correct 1 mark
allow H2
ignore oxygen
2
(c)
(i)
2
2
balancing must be correct
do not accept changed formulae
1
Page 66 of 85
(ii)
increases atmospheric pollution
carbon dioxide / CO2 released
1
from the (thermal) decomposition of calcium carbonate or
accept causes global warming or CO2 is a greenhouse gas
description of this decomposition or equation
ignore sulfur dioxide and effects in this part
1
decreases atmospheric pollution
sulfur dioxide / SO2 is removed
accept less acid rain produced
1
by reaction with calcium oxide or calcium carbonate
accept neutralisation or forms calcium sulfate
1
[10]
M11.
(a)
(i)
H2O
must be formula
1
CaO
must be formula
1
(ii)
carbon dioxide from the air / (Earth’s early) atmosphere
it = carbon (dioxide)
accept carbon dioxide from millions of years ago
1
formed (sedimentary) rocks or fossil fuels
ignore trapped / stored
1
(b)
(i)
decreases rapidly at first
it = carbon (dioxide)
1
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 CO2 decreased for 1 mark
1
Page 67 of 85
(ii)
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
1
which causes global warming (to increase)
allow (carbon dioxide) causes greenhouse effect/climate change
1
or
(no)
because the percentage of carbon dioxide is low (1)
compared to millions of years ago (1)
allow global warming can be caused by other factors (e.g. Sun /
water vapour / methane)
[10]
Page 68 of 85
M12.
(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
1
any methane that evaporates will condense
accept boils for evaporates
accept cooling and produce rain for condensing
1
(c)
CnH2n
1
[5]
M13.
(a)
methane
1
Page 69 of 85
because at the surface temperature of −179°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
1
(b)
CH4 is a hydrocarbon or methane / carbon monoxide contains carbon or carbon
monoxide + hydrogen → hydrocarbon
1
nitrogen and hydrogen are present in Titan’s atmosphere or
nitrogen + hydrogen → ammonia
1
carbon monoxide contains oxygen or
carbon monoxide + hydrogen / methane → water
1
amino acids contain carbon, hydrogen, nitrogen + oxygen or amino acids can be
made from (methane), hydrogen, carbon monoxide and nitrogen
1
OR
lightning / ultraviolet / electrical discharge / high energy needed for reaction
[6]
M14.
(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
1
(ii)
because the (Earth’s) crust
1
(is divided into tectonic) plates
1
the heat (released) from radioactive processes
1
causes convection currents
1
in the mantle (that move the tectonic plates)
1
(b)
(i)
forms a solid or freezes
accept would block pipes
1
(ii)
neon
1
Page 70 of 85
(iii)
argon
1
because the boiling points are almost the same or only 3 degrees different
do not allow reference to melting points
1
[10]
M15.
(a)
(i)
2,4 drawn (as dots / crosses / e–)
1
(ii)
Water (vapour) / steam
allow hydrogen oxide / H2O
do not accept hydroxide
1
(b)
any two pairs from:
carbon dioxide (1)
causes global warming (1)
allow greenhouse effect / climate change / sea level rise / melting
of polar ice caps
or
carbon (particles) / soot (1)
allow particulates
causes global dimming (1)
allow blocks out sunlight / smog / prevents plant growth / causes
breathing difficulties
or
carbon monoxide (1)
is toxic (1)
or
sulfur dioxide (1)
causes acid rain (1)
allow kills plants / erosion / acidifies water
4
[6]
M16.
(a)
argon / Ar
1
(b)
(i)
0
1
Page 71 of 85
(ii)
unreactive
1
(c)
(i)
94.96(%)
1
(ii)
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]
M17.
(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.
1
Page 72 of 85
(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 1 (1−2 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]
M18.
(a)
(i)
the polymer is not biodegradable
1
the polymer is waterproof
1
(ii)
any one from:
•
made from a renewable / sustainable resource
•
is biodegradable
ignore releases less carbon dioxide
allow decomposes.
1
Page 73 of 85
(b)
(i)
crushing
in the correct order
1
filtering
1
(ii)
open the tap
1
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
1
(c)
(i)
They provide a lot of energy
1
(ii)
because the vegetable / plant absorbs / uses carbon dioxide
1
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
1
[10]
Page 74 of 85
M19.
(a)
if only formula given it must be correct
any three from:
•
ammonia
accept NH3
•
methane
accept CH4
allow ethane / butane / propane
•
hydrogen
accept H2
•
water vapour
accept H2O vapour / steam
•
carbon dioxide
accept CO2
•
carbon monoxide
accept CO
allow oxygen / O2
allow nitrogen / N2
ignore nitrogen oxide
ignore carbon
3
(b)
(in atmosphere today)
ignore references to water vapour
allow converse
(much) less carbon dioxide / CO2
allow carbon dioxide was the main gas (in Earth’s early
atmosphere)
1
more nitrogen / N2
allow nitrogen is now the main gas (in the atmosphere today)
or
nitrogen is now 78 × 80%
1
more oxygen / O2
1
no ammonia / NH3 or less methane / CH4 or more argon / Ar or more noble gases
allow less ammonia / NH3
1
Page 75 of 85
(c)
(fractional) distillation
1
gases have different boiling points
allow gases condense at different temperatures
ignore condensing points / levels
ignore evaporating points / levels
1
[9]
M20.
(a)
(i)
water vapour
allow steam
1
condensed
allow cooled to form a liquid / water
second marking point can only be awarded if first marking point
correct
1
(ii)
carbon dioxide
allow CO2
C and O must be upper case
numbers in formulae must be subscript
do not accept carbon (mon)oxide / CO
1
(iii)
ammonia
1
methane
1
(b)
nitrogen
1
oxygen
1
(c)
(i)
combustion
1
(ii)
in calcium carbonate
1
in fossil fuels
1
[10]
Page 76 of 85
M21.
(a)
(i)
12
1
(ii)
(oxygen) produced by algae / plants
1
during photosynthesis
1
(iii)
catastrophe / volcano / asteroid
1
destroyed most algae / plants
dependent on first marking point
1
(b)
gives some support since showed that organic compounds might have
been formed in early atmosphere
allow yes since it showed organic compounds formed
1
but no evidence of structures / living organisms
1
[7]
M22.
(a)
A – core
ignore references to inner and outer throughout
1
B – atmosphere / lithosphere
1
C – crust
1
D – mantle
allow magma
1
(b)
carbon dioxide / noble gas / named noble gas
accept CO2 for carbon dioxide
accept correct symbol for noble gases
1
nitrogen
accept N2
1
Page 77 of 85
oxygen / water vapour
accept O2 / H2O
1
[7]
M23.
(a)
(i)
80(%)
allow answers in range 78–80(%)
1
(ii)
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 1 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 / 100°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
1
B = core
ignore inner / outer
1
Page 78 of 85
(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
1
(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
1
[6]
M25.
(a)
(i)
oxygen
allow O2
must have uppercase O and subscript 2
ignore O
1
(ii)
20 (cm3)
allow 18–22 (cm3)
1
(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 O2 for Oxygen
allow CuO for copper oxide
1
(b)
(i)
nitrogen
allow N2
must have uppercase N and subscript 2 ignore N
1
Page 79 of 85
(ii)
any one from:
•
carbon dioxide
allow CO2
must have uppercase letters and subscript 2
•
argon
accept named noble gas or correct symbol
allow Ar
do not allow Ar2
•
water vapour
ignore steam
allow nitrogen / N2 if not given in (b)(i)
1
[5]
M26.
(a)
(i)
78 %
1
(ii)
A – nitrogen
allow N2
N must be uppercase and 2 must be subscript
ignore N
1
B – oxygen
allow O2
O must be uppercase and 2 must be subscript
ignore O
1
(b)
(i)
any two from:
•
level up to 1900 (allow 1890 to 1910)
•
increasing from 1900 to today (allow 1890 to 1910)
allow increased by 90 (ppm), allow answers in the range 88 – 92
•
increased more rapidly in last 50 years
if no other marks gained allow 1 mark for it has increased
2
(ii)
(fossil) fuels
accept coal / oil / (natural) gas / peat
allow petrol / diesel / methane
1
[6]
Page 80 of 85
M27.
(a)
(i)
global dimming
allow smog
1
(ii)
incomplete / partial combustion (of hydrocarbon fuels)
allow description eg too little oxygen / O2 / air.
1
(b)
(i)
Any 3 from:
ignore name of acid
ignore references to limestone / calcium carbonate dissolving
•
limestone is (mainly) calcium carbonate
allow correct formula, CaCO3
•
(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
(ii)
(polycarbonates) contain carbonate
allow (windows) made of polycarbonate
1
(so) could react in a similar way to limestone
1
[7]
M28.
(a)
burning of fossil fuels
accept burning of a named fossil fuel
1
(b)
Change:
carbon dioxide dissolves / is absorbed by oceans / water
accept ocean acts as a reservoir / store
1
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
1
Page 81 of 85
(c)
(i)
422
allow answers in range of 418-430
1
(ii)
from 1980 to 2010 carbon dioxide increased by 50ppm and coral decreased by
50%
allow answers in range of 48-52 ppm
1
from 2010 to 2020 carbon dioxide increased by 32 ppm,
allow answers in range of 30-40 ppm
allow ecf from part (i) with a tolerance of ± 2 ppm
1
(so) would expect coral to decrease by half again
accept increasing rate of change of carbon dioxide / coral
or
exponential rate of change of carbon dioxide / coral
1
[7]
M29.
(a)
burning fossil fuels
1
(b)
point correctly plotted at 2020, 430
allow ± ½ square
1
suitable curve drawn through most of the points
allow ecf for plotted point
1
(c)
amount of carbon dioxide increases
ignore references to figures unqualified
if carbon dioxide is given as CO2 it must be written correctly
1
(so) amount of coral decreases
accept coral is killed
ignore references to other organisms
1
[5]
M30.
(a)
(i)
solid particles
accept soot / carbon / unburnt fuels
1
(ii)
global dimming
allow smog
1
Page 82 of 85
(iii)
any two from:
•
•
•
•
•
•
•
irregular pattern in the graph
cannot predict future development of industry / technology
cannot predict future number of cars
cannot predict future efficiency / type of engines
might be other sources of particulates in future
change in amount of fossil fuels burnt
cannot predict future volcanic eruptions
allow change in use to other fuels / energy sources
2
(b)
(i)
rate of decay is lower
allow rate of decay is less
1
(because) less acid rain
must refer to idea of less / reduced / not as much acid rain
1
(as) sulfur dioxide is a cause of acid rain
or
limestone / calcium carbonate reacts with acid (rain)
not corrodes
1
(ii)
any one from:
•
•
remove (sulfur dioxide) from waste gases
accept (sulfur dioxide) reacted with limestone / calcium carbonate /
calcium hydroxide / calcium oxide
accept flue gas desulfurisation
use low sulfur fuels
1
[8]
M31.
(a)
combustion
1
Page 83 of 85
(b)
Substance
Environmental effect
extra lines from substance negates mark
3
[4]
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Page 85 of 85