Why should we be careful not to waste the Earth's resources?
Because the resources are limited
2 of 18
Name three gases that scientists think were in the Earth's early atmosphere
Ammonia, methane and hydrogen
3 of 18
Name four gases that are now in the atmosphere
Nitrogen, oxygen, carbon dioxide and argon
4 of 18
How did oceans form?
When the Earth cooled down the water vapour in the atmosphere condensed
5 of 18
What was the effects of algae and plants on the early atmosphere
The removed carbon dioxide and replaced it with oxygen
6 of 18
What are tectonic plates?
Large pieces of the Earths crust
7 of 18
Why do tectonic plates move?
They move because of convection currents in the mantle
8 of 18
About how much do tectonic plates move in a year?
A few centimetres
9 of 18
What happens at plate boundaries?
Earthquakes and volcanic eruptions occur and mountains form
10 of 18
Why have the amounts of gases in the atmosphere been almost the same for the last 200 million years?
Natural processes maintain a balance from the carbon moving in and out o the atmosphere due to plants, animals, oceans and rocks
11 of 18
What has been the main cause of a change in the amount of gases in recent years?
Burning fossil fuels
12 of 18
Why were Wegener's ideas not accepted until the 1960's?
Because the he could not prove that the continents moved until the 1960's when new evidence was discovered
13 of 18
Why are there so many theories about how life began?
There is insufficient evidence and there are many possibilities but no proof
14 of 18
Outline the Miller and Urey experiment
They used a mixture of water, ammonia, methane and hydrogen and used a small electric spark to timulate lightning which produced amino acids from which proteins are made
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What is meant by primordial soup?
A mixture of organic amino acids needed for life in water
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Why is the fractional distillation of liquid air done commercially?
To separate the air into individual gases, to produce nitrogen and oxygen, which are raw materials
17 of 18
Explain briefly how the fractional distillation of liquid air is done
Air is cooled until it becomes liquid which is then put into a fractionating column. Nitrogen is collected as a gas at the top of the column and oxygen remains as a liquid and is colelcted at the bottom
18 of 18
Other cards in this set
Card 2
Front
Why should we be careful not to waste the Earth's resources?
Back
Because the resources are limited
Card 3
Front
Name three gases that scientists think were in the Earth's early atmosphere
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