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30 Cards in this Set
- Front
- Back
What percentage of each gas makes up the Earth’s atmosphere?
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Oxygen= 21% Nitrogen=78% CO2= 0.037 Argon= 0.9
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What is the percentage of nitrogen in the air?
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78%
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What is the percentage of oxygen in the air?
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21%
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What is the percentage of argon in the air?
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0.9
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What is the percentage of carbon dioxide in the air?
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0.037
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Where did the early gases come from?
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Volcanoes
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What were the main gases in the early atmosphere?
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Carbon dioxide and water vapour
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Name one way that oxygen levels increased
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Photosynthesis
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Name three ways that carbon dioxide levels decreased
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Dissolving in the ocean, locked up in fossil fuels and sedimentary rocks, photosynthesis by green plants
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What happened to the water vapour from volcanoes?
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It condensed and formed oceans when the Earth cooled
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Which two pollutants cause acid rain?
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Sulphur dioxide and nitrogen dioxide
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Which pollutant gas is poisonous?
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Carbon monoxide
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Which pollutant makes things dirty and causes breathing problems?
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Particulates
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What problem does carbon dioxide cause?
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Global warming
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What is the best estimate of a set of data?
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The calculated mean
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What are the main pollutants?
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Particulates, Carbon dioxide, Nitrogen oxide, Carbon monoxide, nitrogen dioxide, sulphur dioxide
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What are the products of incomplete combustion?
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Carbon monoxide and carbon
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What group of compounds do petrol, diesel fuel and fuel oil belong to?
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Hydrocarbons
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Why does a yellow flame produce a ‘sooty’ bottom?
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Because the fuel is burning with a lack of oxygen and producing carbon.
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How do you know if data is repeatable?
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Repeated measurements are similar
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What happens to the atoms during a chemical reaction?
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During a chemical reaction, reactants contact each other. Bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
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Where does nitrogen dioxide come from?
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From the nitrogen and oxygen in air reacting inside hot engines. Some is formed naturally by lightning and some is produced by plants, soil and water.
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What happens to the carbon dioxide in the atmosphere?
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Dissolves in the oceans, locked in sedimentary rocks and absorbed in photosynthesis.
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Give an example of a correlation between a factor and an outcome that does not mean that one causes the other?
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Being overweight and having an unhealthy lifestyle can lead to heart disease but they have not been proven to be the direct cause of heart disease.
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What is needed to show that a factor causes an outcome – give an example.
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A fair test. Keep one thing the same and change the rest. That results in a correlation.
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How can you prove that there is a real difference between 2 sets of data?
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The range bars do not overlap. The mean of one set of data lies outside the range of the other.
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Recall 3 ways of reducing pollution caused by power stations.
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Wet scrubbing, removing sulphur from the fuel before it is burnt, dust precipitator.
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Give 4 ways that exhaust emissions from motor vehicles can be reduced?
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Efficient engines, using low sulphur fuels, using catalytic converters, setting legal limits on exhaust emissions.
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How would you calculate the mean if a set of data contained an outlier?
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Leave the outlier out.
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How can the levels of carbon dioxide be reduced?
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Burn less fossil fuels.
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