1. L1.05 Clean Air Lesson Outcomes How I did Targets Task 1:
APP AF4
HSW 1a,1b,3a & 3c
How I did
Targets
Task 1:
Recall the percentage of the main gases in the air
Grade C
Task 2:
Describe how the present day atmosphere evolved
Grade B
Task 3:
Explain how gases from the air can be separated and their uses
Grade A/A*
Connector: (Grade D)
Would humans be able to live on Mars and Venus without any support? Explain your answer.
Why is it about conditions on Earth that allow us to exist on it?

2. However today it is much different – how?
Today, Mars and Venus’ atmosphere consists of large quantities of carbon dioxide (CO2), along with methane (CH4) , and ammonia (NH3)
This is what the atmosphere on Earth for the first billion years would have been like.
However today it is much different – how?
Mars
Venus
The Earth’s atmosphere would also have contained water vapour which condensed to form the oceans. 2

3. Homework Homework task:
Create a presentation showing a timeline for the evolution of the Earth’s atmosphere.
Due date: ??/??/??
Criteria for Grade C:
Criteria for Grade B:
Criteria for Grade A/A*:

4. BIG picture What skills will you be developing this lesson?
Numeracy
Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection
How is this lesson relevant to every day life? (WRL/CIT)

5. Keywords: Atmosphere Photosynthesis Volcanic activity
Can you explain these key words?
Atmosphere
Photosynthesis
Volcanic activity

6. New Information for Task 1
Demonstration
1 Hot copper reacts with oxygen in the air to form copper oxide. Write a word equation for the reaction.
2 Why does the volume of gas change during the experiment?
3 Calculate the volume of oxygen in the original 100 cm3 of air (the difference between the starting volume and the final volume).
4 Use your answer to question 3 to calculate the percentage of oxygen in the air. How close to the accepted percentage is this?

7. 1 copper + oxygen → copper oxide
Task 1 Answers (Grade C)
Task 1:
1 copper + oxygen → copper oxide
2 Oxygen reacts with the hot copper and is removed from the air.
3 Typical answer: final volume is 79 cm3, so volume of oxygen is 100 − 79 = 21 cm3
4 Answer depends on the answer to question 3, e.g. 21%.

8. New Information for Task 1

9. How can I improve on task 1?
Task 1: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 1:
Grade C
Met?
Partly met?
Not met?
How can I improve on task 1?

10. New Information for Task 2
In the beginning -
Jupiter
The Earth was formed about 4500 million years ago.
The very first atmosphere mainly consisted of hydrogen and helium gases.
Frozen giant planets like Saturn and Jupiter still have atmospheres like this but on the warmer, smaller Earth these light gases were largely lost into space.
Saturn

11. New Information for Task 2
The early atmosphere
During the first billion years on Earth there was intense volcanic activity. This produced the next early atmosphere.
It would have contained large quantities of carbon dioxide (CO2), along with methane (CH4) , and ammonia (NH3).
This is rather like the atmosphere on Mars and Venus today.
Mars
Venus

12. New Information for Task 2
Oxygen levels increase
Carbon dioxide reacted with rocks and much became trapped in them.
The evolution of algae some 3000 million years ago, and subsequently plants which successfully colonised the Earth’s surface, led us towards the present atmosphere.
Their photosynthesis replaced carbon dioxide with oxygen.
Earth
Photosynthesis increased oxygen levels

13. Task 2 (Grade B) Task 2: Keywords for Task 2:
The first atmosphere of the Earth, __________ billion years ago, was nearly 100% __________ . Once plants evolved, carbon dioxide was taken out of the air and replaced in part by __________ . For the last million years, there has been less than 0.1% of carbon dioxide in the air. The exact amount has varied as the Earth’s __________ has flipped between __________ and __________ periods. Predictions of climate change are made using complex computer __________- the ones used for weather forecasting. They are not __________ and so, like a weather forecast, could be wrong. You can follow the debate on the __________ , but watch out for __________ .
Keywords for
Task 2:
bias
carbon dioxide
climate
cold
hot
internet
models
oxygen
perfect 4½

14. Task 2: Answers
The first atmosphere of the Earth, __________ billion years ago, was nearly 100% __________ . Once plants evolved, carbon dioxide was taken out of the air and replaced in part by __________ . For the last million years, there has been less than 0.1% of carbon dioxide in the air. The exact amount has varied as the Earth’s __________ has flipped between __________ and __________ periods. Predictions of climate change are made using complex computer __________- the ones used for weather forecasting. They are not __________ and so, like a weather forecast, could be wrong. You can follow the debate on the __________ , but watch out for __________ .
4 ½
Carbon dioxide
oxygen
climate
hot
cold
models
perfect
internet
bias

15. How can I improve on task 2?
Task 2: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 2:
Grade B
Met?
Partly met?
Not met?
How can I improve on task 2?

16. Before the distillation happens, what needs to happen to the air?
Task 3: (Grade A/A*)
Before the distillation happens, what needs to happen to the air?
At the bottom of the column, what will be a gas and what will be liquid?
What will be gas and what will be liquid at the top of the column?
Oxygen b.p.= -183°C
Nitrogen b.p.= - 196°C

17. Uses of Oxygen
Use of pure oxygen? – the pictures gives clues to three main uses:

18. Uses of Nitrogen
Use of Nitrogen? – the pictures gives clues to some uses:

19. List the uses of oxygen and nitrogen.
Task 3: (Grade A/A*)
Task 3:
Write a paragraph using the keywords on the right to explain how oxygen and nitrogen are separated from air.
List the uses of oxygen and nitrogen.
Keywords for Task 3:
distillation
fractionating tower
recondense
-183°C (b.p. oxygen)
-196°C (b.p. nitrogen)
cooling system

20. Task 3: Answers

21. How can I improve on task 3?
Task 3: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 3:
Grade A/A*
Met?
Partly met?
Not met?
How can I improve on task 3?

22. Review of lesson
With the people either side of you summerise the evolution of the atmosphere on Earth.
Some of you will be chosen to feed back to the class – you have 5 minutes.

23. Technicians’ List
Task 1 Demo:
Eye protection, Safety screen, Borosilicate glass tube, Bunsen burner, Two gas syringes, Heatproof mat, Two stands and clamps, Tubing to connect apparatus, Copper turnings