Download C1.7 Earth and its a..

Q1.
Earth scientists have discovered that the Earth has three layers.
The diagram shows the three layers of the Earth.
(a)
Complete the table by writing the letters, A, B or C, from the diagram in the correct box.
Layer of Earth
Letter
Core
Crust
Mantle
(2)
(b)
Draw a ring around the correct answer to complete each sentence.
(i)
Earth scientists think that, since the Earth formed, the surface of the Earth
warmed up.
has
stayed the same temperature.
cooled down.
(1)
crust
(ii)
The outer layers of the Earth are cracked into pieces called
mantle
plates.
tectonic
(1)
conduction
(iii)
These plates move because of
convection
currents under the Earth’s
core
surface.
(1)
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droughts.
(iv)
This movement can cause
hurricanes.
volcanic eruptions.
(1)
(c)
The table gives information on some gases in the Earth’s atmosphere.
Gas
Percentage in
atmosphere 2.5
billion years ago
Percentage in
present day
atmosphere
Nitrogen
29 %
78 %
Oxygen
9%
21 %
Carbon dioxide
58 %
0.03 %
Calculate the increase in the percentage of oxygen in the atmosphere.
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(1)
(Total 7 marks)
Q2.
Billions of years ago, the Earth’s early atmosphere was probably like the atmosphere of
Venus today.
The table shows a comparison of the atmospheres of the Earth and Venus today.
Percentage composition of atmosphere
Name of gas
Earth today
Venus today
Nitrogen
78
3.5
Oxygen
21
a trace
Argon
0.97
a trace
Carbon dioxide
0.03
96.5
Average surface
temperature
20 ºC
460 ºC
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(a)
Use the names of gases from the table to complete the sentences.
(i)
In the Earth’s atmosphere today, the main gas is .................................................. .
(1)
(ii)
In the Earth’s atmosphere billions of years ago, the main gas was
............................................................ .
(1)
(b)
(i)
Scientists do not know the accurate composition of the Earth’s early atmosphere.
Suggest why.
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(1)
(ii)
Use information from the table to answer this question.
Water vapour is present in the atmospheres of the Earth and Venus today.
The Earth’s surface is mainly covered by water.
Suggest why there is no water on the surface of Venus.
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(1)
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(c)
The diagram shows how carbon dioxide is removed from the Earth’s atmosphere.
Describe what happened to the carbon dioxide in the Earth’s early atmosphere.
Use the diagram to help you.
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(3)
(Total 7 marks)
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Q3.
The following information suggests that South America and Africa were once attached and
then moved apart.
Suggest when South America and Africa began to move apart.
[Make use of dates in your answer, where possible.]
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(Total 3 marks)
Q4.
(a) Two hundred years ago, scientists thought that the Earth was about 400 million years
old. This estimate came from the idea that the centre of the Earth was still molten. More
recently, measurement of radioactivity in rocks has shown that the Earth is much older
than 400 million years.
Suggest one reason why scientists now know that the Earth is much older than 400
million years.
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(1)
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(b)
About one hundred years ago there was a scientist called Alfred Wegener. He found
evidence that the continents, such as South America and Africa, had once been joined and
then drifted apart.
Use the diagram to suggest two pieces of evidence that could be used to show that the
continents had once been joined.
1 ..................................................................................................................................
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2 ..................................................................................................................................
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(2)
(c)
About fifty years ago, new evidence convinced scientists that the Earth’s crust is made up
of tectonic plates that are moving very slowly.
Give two pieces of evidence that have helped to convince these scientists that the
tectonic plates are moving.
1 ..................................................................................................................................
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2 ..................................................................................................................................
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(2)
(Total 5 marks)
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Q5.
Life on Earth would not exist without the atmosphere. Billions of years ago the composition
of the Earth’s atmosphere was very different from the composition today.
(a)
Label the pie chart below to show the percentages and names of the two main gases in
the Earth’s atmosphere today.
(2)
(b)
There is evidence that the composition of the Earth’s atmosphere is still changing. One
possible reason is that many power stations generate electricity by burning fossil fuels
such as coal, oil or natural gas. Sulfur dioxide, SO2, is produced when coal burns in air.
(i)
What environmental problem does sulfur dioxide cause?
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(1)
(ii)
How could this environmental problem be reduced in coal-fired power stations?
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(1)
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(iii)
Gas-fired power stations burn methane, CH4, in air.
Complete the word equation for this reaction.
methane + ............................... → carbon dioxide + ...............................
(2)
(c)
Excess carbon dioxide should be prevented from entering the atmosphere.
Explain why.
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(2)
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(d)
Carbon dioxide is produced when fossil fuels burn in power stations. The diagram
represents one idea to prevent excess carbon dioxide from entering the atmosphere.
Use the diagram to explain how carbon dioxide can be prevented from entering the
atmosphere.
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(2)
(Total 10 marks)
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Q6.
(a) For the last 200 million years the amount of carbon dioxide in the atmosphere has
remained almost the same.
Describe the natural processes which remove carbon dioxide from the atmosphere.
To gain full marks in this question you should write your ideas in good English.
Put them into a sensible order and use the correct scientific words.
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(4)
(b)
The amount of carbon dioxide in the atmosphere has increased over the last one hundred
years. Suggest two reasons why this has happened.
1 ...................................................................................................................................
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2 ...................................................................................................................................
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(2)
(Total 6 marks)
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M1.
(a)
core - C
crust - A
mantle - B
2 marks if all three correct
1 mark if one or two correct
2
(b)
(i)
cooled down
1
(ii)
tectonic
1
(iii)
convection
1
(iv)
volcanic eruptions
1
(c)
12 %
1
[7]
M2.
(a)
(i)
nitrogen / N2
1
(ii)
carbon dioxide / CO2
1
(b)
(i)
humans / scientists had not evolved
accept it was billions / millions of years ago
allow too long ago
1
(ii)
temperature is above 100°C or any water would evaporate / boil
accept Venus is too hot
1
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(c)
any three from:
•
used by plants
•
used for photosynthesis
accept plants take in carbon dioxide and give out oxygen for the
first two bullet points ie 2 marks
•
dissolves in oceans / seas
allow absorbs into oceans / seas
•
used to form the shells / skeletons of marine organisms
•
locked up as limestone / carbonates
•
locked up as fossil fuels / oil / coal
3
[7]
M3.
idea that:
continents had not drifted apart at the end of the Permian period
continents had not drifted apart 230 million years ago*
continents moved apart before the Jurassic period
continents moved apart prior to 195 million years ago*
continents moved apart in Triassic period
(* credit single figure in range 195-230 million years ago)
any 3 for 1 mark each with 1 mark
[3]
M4.
(a)
radioactivity (keeps the core hot)
accept half-life of radioactive elements has proved the Earth is
older than 400 million years
accept the Earth is not cooling
do not accept fossil / rock evidence
1
(b)
any two from:
•
the shapes of the two continents fit together (like a jigsaw) OWTTE\
do not accept the continents / they are the same shape
•
the same type of rocks have been found
accept ‘rocks match’
•
the same fossils have been found
accept ‘fossils match’
•
rising magma rising through a gap under the Atlantic
2
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(c)
any two from:
•
earthquakes
accept seismic waves
•
volcanoes
•
idea of distance between America and Europe / Africa is increasing e.g.
continental drift
•
oceanic ridges
accept ocean floor spreading
•
formation of (new) mountain ranges
accept fold mountains or mountains increasing in height
•
formation of (new) islands
•
magnetic stripes
•
tsunamis
2
[5]
M5.
(a)
oxygen and nitrogen
1
20 – 21 % and 78 – 80 %
accept any two correct responses in the correct space for one
mark
1
(b)
(i)
acid rain
accept toxic gas or consequence of acid rain
1
(ii)
idea of the removal or use of sulfur
dioxide gas (from the waste gases)
do not accept remove sulfur from coal
1
(iii)
oxygen
accept O2
1
water
accept H2O
accept hydrogen oxide / steam
1
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(c)
any two from:
•
it’s a ‘greenhouse gas’ or increase greenhouse effect
accept action of a ‘greenhouse gas’
•
causes global warming or increase in the Earth’s temperature
•
sea-levels rise or flooding
•
climate change
•
(polar) ice-caps melt
•
extension of deserts
mention of ozone / acid rain / global dimming = max 1 mark
2
(d)
idea trap / store / lock the carbon dioxide
1
in the oil reservoir or under the sea bed
do not accept ‘into the oil’ / ‘under the sea’
1
[10]
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M6.
(a)
Quality of written communication
for any two ideas sensibly stated
1
any three from:
•
plants take in (CO2)
accept photosynthesis uses (CO )
•
converted to glucose / starch / carbohydrates
ignore carbon compounds by itself
•
CO2 locked up in fossil fuels
accept coal / oil / natural gas / methane for fossil fuels
•
CO2 reacts with / dissolves (sea)water
accept ocean removes CO2
•
producing hydrogencarbonates
accept carbonic acid
•
producing carbonates
accept named carbonates
•
marine animals use carbonates to make shells
do not accept bones
•
forms sedimentary rocks
accept limestone / chalk
accept marble
do not accept sediments alone
3
(b)
any two from:
•
burning of fossil fuels or cars /
industry / air travel / power stations
ignore increase in population
ignore more use of electricity
•
natural processes cannot absorb all the extra CO2
•
deforestation
accept less photosynthesis
ignore volcanic activity
accept burn trees
2
[6]
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