Transcript Slide 1

Connection
•
•
•
Connect your learning to the
content of the lesson
Share the process by which the
learning will actually take place
Explore the outcomes of the
learning, emphasising why this will
be beneficial for the learner
Demonstration
• Use formative feedback – Assessment for
Learning
• Vary the groupings within the classroom
for the purpose of learning – individual;
pair; group/team; friendship; teacher
selected; single sex; mixed sex
• Offer different ways for the students to
demonstrate their understanding
• Allow the students to “show off” their
learning
Activation
Consolidation
• Construct problem-solving
challenges for the students
• Use a multi-sensory approach – VAK
• Promote a language of learning to
enable the students to talk about
their progress or obstacles to it
• Learning as an active process, so the
students aren’t passive receptors
• Structure active reflection on the lesson
content and the process of learning
• Seek transfer between “subjects”
• Review the learning from this lesson and
preview the learning for the next
• Promote ways in which the students will
remember
• A “news broadcast” approach to learning
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“C1.7 Our Changing
Planet”
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Overview....
The Earth and its atmosphere provide everything we need. The Earth has a layered structure.
The surface of the Earth and its atmosphere have changed since the Earth was formed and are still
changing.
The atmosphere has been much the same for the last 200 million years and provides the conditions
needed for life on Earth.
Recently human activities have resulted in further changes in the atmosphere. There is more than
one theory about how life was formed.
recognise that the Earth’s crust, the atmosphere and the oceans are the only source of minerals and
other resources that humans need.
explain why Wegener’s theory of crustal movement (continental drift) was not generally accepted for
many years
explain why scientists cannot accurately predict when earthquakes and volcanic eruptions will occur
explain and evaluate theories of the changes that have occurred and are occurring in the Earth’s
atmosphere
explain and evaluate the effects of human activities on the atmosphere
describe why we do not know how life was first formed. (HT Only)
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Where does it all come from?
Product
Raw material
copper
sand
cooking oil
sunflower seeds
glass
clay
denim
copper ore
brick
wheat plants
plastic
crude oil
flour
cotton plants
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C7.1 Structure of the Earth
C1.7.1 The Earth’s Crust
a) The Earth consists of a core,
mantle and crust, and is
surrounded by the atmosphere.
(Limited to the names of the three
major parts, and an awareness of
the relative sizes of these
features).
b) The Earth’s crust and the upper
part of the mantle are cracked into
a number of large pieces (tectonic
plates). (Knowledge of the names,
shapes or locations of specific
plates is not required.)
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a) Structural Features...
TASK:
1.
In the centre of a page
copy out the diagram as
neatly as possible leaving
space for extra labels (Low
Demand)
2.
Add more information
from the textbook p96/97
using the table and text.
(Standard Demand)
3.
Explain in a paragraph
how we have answered
questions about the
structure of the Earth,
density, type of materials.
(Higher Demand)
Extras....
Answer Q1 (Low Demand)
Copy out the key points (Low Demand)
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Simple Earthquake Diagram....
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b) Tectonic Plates p98/99
TASK:
1.
Using the information on page
98 construct a diagram to show
the idea the crust is made up of
individual plates. Make sure you
label it clearly (Low Demand)
2.
Write a short glossary of terms
to explain the idea of; tectonic
plates, convection currents,
boundaries. (Standard Demand)
3.
Explain in a paragraph what
Wegener's theory was. (Higher
Demand) p99
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Chemistry C1 7.1
Answers to in-text questions
Structure of the Earth
a crust
b mantle
Summary answers
1 core, mantle, crust, atmosphere, thin, solid, slowly
2 It can flow but only very slowly.
3 Because all the raw materials we need come from the crust, oceans and
atmosphere and many of them, such as mineral deposits, are nonrenewable – once we have used them up they will not be replaced.
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C7.2 The Restless Earth
C1.7.1 The Earth’s Crust
c) Convection currents within the Earth’s
mantle driven by heat released by natural
radioactive processes cause the plates to move
at relative speeds of a few centimetres per year.
(Candidates should know that the mantle is
mostly solid, but that it is able to move slowly.)
d) The movements can be sudden and
disastrous. Earthquakes and / or volcanic
eruptions occur at the boundaries between
tectonic plates. (to earthquakes and volcanic
eruptions with the mechanism not required).
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TASK: Draw a diagram of this process and write a paragraph to explain what happens
(Low-High Demand)
c) Convection currents within the Earth’s
mantle driven by heat released by natural
radioactive processes cause the plates to
move at relative speeds of a few centimetres
per year. (Candidates should know that the
mantle is mostly solid, but that it is able to
move slowly.)
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TASK: Draw your own diagram of each process and write a paragraph to explain what
happens (Low-High Demand)
d) The movements can be sudden and
disastrous. Earthquakes and / or volcanic
eruptions occur at the boundaries
between tectonic plates. (to earthquakes
and volcanic eruptions with the
mechanism not required).
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Chemistry C1 7.2
The restless Earth
Answers to in-text questions
a The similar shapes of their coastlines, similar rock types, similar fossils.
b Tectonic plates suddenly slipping past one another after stress builds up
at their boundaries. These sudden movements cause earthquakes.
Summary answers
1 tectonic, convection, mantle, volcanoes (earthquakes), earthquakes
(volcanoes)
2 a Convection currents, caused by energy from natural radioactive
processes, form in the mantle beneath the tectonic plates.
b Although we know where plate boundaries lie, we cannot tell exactly when
and where the forces building up will cause the sudden movement that
produces an earthquake or when the magma building up in a volcano will
cause an explosive eruption.
3 Letter. [Mark based on ideas from description of Wegener’s
ideas in the spread.]
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C7.3 The Earth’s Atmosphere in the Past
b) During the first billion years of the Earth’s existence there was intense volcanic activity. This
activity released the gases that formed the early atmosphere and water vapour that condensed to
form the oceans.
c) There are several theories about how the atmosphere was formed. One theory suggests that
during this period the Earth’s atmosphere was mainly carbon dioxide and there would have been
little or no oxygen gas (like the atmospheres of Mars and Venus today). There may also have been
water vapour and small proportions of methane and ammonia.
f) Plants and algae produced the oxygen that is now in the atmosphere. (Candidates should be
aware that plants and algae produce oxygen by a process called photosynthesis and that this process
uses carbon dioxide from the atmosphere. Knowledge of the process of photosynthesis is not
required.)
C1.7.2 The Earth’s atmosphere
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a) Earth’s atmosphere (page 100)
TASK: Draw your own diagram which is then explained to show the composition of
the Earth’s atmosphere. happens (Low-Medium Demand)
a) For 200 million years, the proportions
of different gases in the atmosphere
have been much the same as they are
today:
•
•
•
about four-fifths (80%) nitrogen
about one-fifth (20%) oxygen
small proportions of various other
gases, including carbon dioxide, water
vapour and noble gases.
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b) Volcanic Activities (page 100)
TASK: Explain to the person next to you how a volcanic eruption could make an
atmosphere and oceans. (Low Demand) Now write out the steps you explained
in a flow chart. (Medium Demand)
b) During the first billion years of the Earth’s existence there was intense volcanic
activity. This activity released the gases that formed the early atmosphere and
water vapour that condensed to form the oceans.
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c) Theories on Formation of the atmosphere (page 100-101)
TASK: Draw a bar chart to compare the atmospheres of Venus, mars and Earth. (Low
Demand) Then write a detailed paragraph to explain how they are different and
what that means changed. (Medium Demand)
Gas
Mars
today
Venus
today
Earth
carbon
dioxide
95.3
96.5
0.0379
nitrogen
2.7
3.5
78
argon
1.6
trace
0.9
oxygen,
water
vapour and
other
gases
trace
trace
22
c) There are several theories
about how the atmosphere
was formed.
One theory suggests that
during this period the Earth’s
atmosphere was mainly carbon
dioxide and there would have
been little or no oxygen gas
(like the atmospheres of Mars
and Venus today).
There may also have been
water vapour and small
proportions of methane and
ammonia.
Index
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Oxygen and carbon dioxide: The Earth’s early atmosphere is believed to have been
mainly carbon dioxide with little or no oxygen gas. The Earth’s atmosphere today
contains around 21 percent oxygen and about 0.04 percent carbon dioxide. So how did
the proportion of carbon dioxide in the atmosphere go down, and the proportion of
oxygen go up?
Increasing oxygen: Plants and algae can carry out photosynthesis. This process uses
carbon dioxide from the atmosphere (with water and sunlight) to produce oxygen (and
glucose). The appearance of plants and algae caused the production of oxygen, which is
why the proportion of oxygen went up.
Decreasing carbon dioxide: Photosynthesis by plants and algae used carbon dioxide
from the atmosphere, but this is not the only reason why the proportion of carbon
dioxide went down. These processes also absorb carbon dioxide from the atmosphere:
dissolving in the oceans the production of sedimentary rocks such as limestone the
production of fossil fuels from the remains of dead plants and animals
Today, the burning of fossil fuels (coal and oil) is adding carbon dioxide to the
atmosphere faster than it can be removed. This means that the level of carbon dioxide
in the atmosphere is increasing, contributing to global warming. It also means that the
oceans are becoming more acidic as they dissolve increasing amounts of carbon dioxide.
This has an impact on the marine environment, for example making the shells of sea
creatures thinner than normal.
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Chemistry C1 7.3
The Earth’s atmosphere in the
past
Answers to in-text questions
a carbon dioxide
b very little or none
Summary answers
1 dioxide, water, methane, volcanoes, oxygen
2 From gases emitted by volcanoes.
3 The temperature was too high.
4 Student chart showing development from early volcanicatmosphere to
the fi rst plant-produced oxygen and the removal of carbon dioxide during
photosynthesis.
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C7.4 Life on Earth
d) There are many theories as to how life
was formed billions of years ago.
e) One theory as to how life was formed
involves the interaction between
hydrocarbons, ammonia and lightning. (HT
Only) (Candidates should be aware of the
Miller-Urey experiment and the
‘primordial soup‘ theory, but they should
know that this is not the only theory.)
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Chemistry C1 7.4
Answers to in-text questions
Life on Earth
a carbon, hydrogen, nitrogen and oxygen
b Because it contains organic molecules which support the theory that the
molecules of life might have arrived from outer space.
Summary answers
1 a They reacted a mixture of water, ammonia, methane and hydrogen to
model the early atmosphere. To produce the energy needed for reactions to
take place they used a high voltage. They kept the experiment going for a
week, then analysed the mixture of new compounds formed.
b C – It showed that biological molecules can be made from substance that
could have been in the early atmosphere.
2 a The mixture of organic compounds brewing in prehistoric seas.
b The organic molecules could have reacted together to make biological
molecules, such as self-replicating proteins, that could have gone on to
make the first cells.
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C7.5 Gases in the Atmosphere
a) For 200 million years, the proportions of different gases in the atmosphere
have been much the same as they are today:
■ about four-fifths (80%) nitrogen
■ about one-fifth (20%) oxygen
■ small proportions of various other gases, including carbon dioxide,
water vapour and noble gases.
g) Most of the carbon from the carbon dioxide in the air gradually became
locked up in sedimentary rocks as carbonates and fossil fuels.
j) Air is a mixture of gases with different boiling points and can be fractionally
distilled to provide a source of raw materials used in a variety of industrial
processes. (HT Only) (Knowledge of the boiling points of the different
gases is not required.)
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Chemistry C1 7.5
Gases in the atmosphere
Answers to in-text questions
a into carbonate rocks
b oxygen
Summary answers
2 a fractional distillation
b They solidify out by cooling the air.
c i argon
ii Because the boiling points of argon and oxygen are very close
together.
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C7.6 Carbon Dioxide in the Atmosphere
h) The oceans also act as a reservoir
for carbon dioxide but increased
amounts of carbon dioxide absorbed
by the oceans has an impact on the
marine environment.
i) Nowadays the release of carbon
dioxide by burning fossil fuels
increases the level of carbon dioxide
in the atmosphere.
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The Ocean Cycle
In the oceans, carbon dioxide exchange is largely controlled by sea surface temperatures, circulating currents, and by the
biological processes of photosynthesis and respiration. There is a higher capacity to hold a gas with a lower temperature than
with a higher temperature, which means that more carbon dioxide can dissolve in cold water than in warm. These cold dense
waters sinking at high latitudes are rich in carbon and act to move large quantities of carbon from the surface to deep waters.
This mechanism is known as the "solubility pump" or physical mixing. Cold, downward moving currents such as those that occur
over the North Atlantic absorb carbon dioxide and transfer it to the deep ocean.
Upward moving currents such as those in the tropics bring carbon dioxide up from depths and release it to the atmosphere.
Another key biological process occurs in the ocean carbon cycle when carbon dioxide from the atmosphere dissolves in the
ocean; it undergoes rapid chemical reactions and only a small fraction remains as carbon dioxide. The carbon dioxide and the
associated chemical forms are collectively known as dissolved inorganic carbon or DIC. The presence of organisms like plankton
(microscopic plants and animals) or calcites transports gases and nutrients from the ocean surface to the deep; this movement is
also known as a "biological pump.“ The biological pump, in essence, removes carbon dioxide from the surface water of the
ocean, changing it into living matter and distributing it to the deeper water layers, where it is out of contact with the
atmosphere.
Eventually when plankton decays, the CO2 is then released into the water; most of it becomes absorbed in the sea-water.
Although a small but possibly significant percentage of the sinking organic material becomes buried in the ocean sediment, most
of the dissolved carbon dioxide eventually returned to the surface. This sedimentary process takes place at an extremely low rate
measured in hundreds to thousands of years, meaning that the carbon that is released by human activities will not become
geologically sequestered again for many thousands of years
The Carbon Cycle
The exchange of carbon between the important reservoirs of the
biosphere, atmosphere and oceans is known as the carbon cycle.
TASK:
a.
Read the block of text through once. (Basic)
b.
Highlight each key part or underline. (Basic)
c.
Draw a diagram to show one of the cycles
(Medium Challenge)
d.
Write your own short summary article
explaining the idea behind.. (Harder Challenge)
1.
“Carbon Cycle”
2.
“The Ocean Cycle”
Carbon is an essential component of life on earth and is the basis
for all organic molecules. On land, the major exchange of carbon
with the atmosphere results from photosynthesis and respiration.
Nearly all forms of life on Earth depend on the production of
sugars from solar energy and carbon dioxide (photosynthesis) and
the metabolism (respiration) of those sugars to produce the
chemical energy that facilitates growth and reproduction.
When forests are cleared for agriculture, the carbon contained in
the living material and soil is released, causing atmospheric
carbon dioxide concentrations to increase. When agricultural land
is abandoned and forests are allowed to re-grow, carbon is stored
in the accumulating living biomass and soils, causing atmospheric
carbon dioxide concentrations to decrease.
Carbon is also stored in fossil fuels, such as coal, petroleum, and
natural gas. When these are burned, carbon dioxide is also
released back into the air. Volcanoes and fires also release large
amounts of CO2 into the atmosphere.
Now fold this sheet in two and stick this part in your
book so you can retain the original full
information.
The Carbon Cycle
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