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39 Cards in this Set
- Front
- Back
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What is in the atmosphere that surrounds the earth ? |
Nitrogen- N2 Oxygen -O2 Argon-Ar Water vapour- H20 Carbon dioxide- CO2 other gases |
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What is air ? |
A mixture of different gases consisting of small molecules with large spaces between them |
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Percentage of main gases in the air ? |
78% Nitrogen 21% Oxygen 1% Argon |
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What can affect air quality? |
Other gases or particulates being released into the atmosphere by human activity or by natural processes e.g. volcanoes |
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How was the earth atmosphere formed and what did it contain ? |
by volcanic activity and it consisted of mainly carbon dioxide and water vapour |
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What happened to to water vapour in the early atmosphere? |
Water vapour condensed as the earth cooled to form oceans |
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What did the evolution of of photosynthesising organisms do? |
It added oxygen to the atmosphere and removed carbon dioxide |
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How was carbon dioxide removed from the atmosphere ? |
Carbon dioxide dissolved in the oceans |
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What happened after carbon dioxide was dissolved in the oceans ? |
it formed into sedimentary rocks then later into fossil fuels |
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What elements have human activity added to the air ? |
small amounts of carbon monoxide nitrogen oxides sulphur dioxides extra carbon dioxide small particulates of solid (e.g. carbon) |
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Who are pollutants harmful too? |
they are directly harmful to humans and the environment (acid rain- sulphur dioxide) |
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What does carbon monoxide do to a person? |
It reduces the amount of oxygen that the blood can carry |
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What is coal ? |
it is mainly Carbon |
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What are mainly compounds of hydrocarbons ? |
Petrol diesel fuel fuel oil |
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What is a hydrocarbon ? |
A molecule made up of only carbon and hydrogen atoms |
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When fuels burn, atoms of carbon and/ or hydrogen from the fuel combine with oxygen fro the air to produce..... |
carbon dioxide and/or water (hydrogen oxide) |
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What is it called when substances chemically combine with oxygen ? |
oxidation |
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What is it called when substances loose oxygen |
reduction |
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What do combustion reactions involve ? |
they involve oxidation |
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When do fuels burn more rapidly ? |
In pure oxygen rather than in air |
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What are the properties of the reactants and products in a chemical reaction |
they are all different |
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What happens to atoms in a chemical reaction? |
They are rearranged |
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What happens to the number of atoms at the start (the reactants) and at the end (the products) in a chemical reaction? |
nothing is gained nor lost ( the conservation of mass) |
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What pollutants are caused when burning fossil fuels in power stations and in transport ? |
carbon dioxide, sulfur dioxide, nitrogen oxides, carbon monoxide, particulate carbon |
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What pollutants are caused when burning fossil fuels in power stations and in transport (incomplete combustion) ? |
carbon monoxide, particulate carbon |
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When is Nitrogen monoxide formed ? |
during the combustion of fuels in air |
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methane +oxygen ------> |
carbon dioxide +water |
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air (nitrogen+oxygen) + fuel (mixture of hydrocarbons)-----> |
carbon dioxide, water, nitrogen, carbon monoxide, nitrogen monoxide, carbon particulates |
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Where do atmospheric pollutants go ? carbon |
particulate carbon is deposited on surfaces, making them dirty |
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Where do atmospheric pollutants go ? Sulphur dioxide and Nitrogen dioxide |
react with water and oxygen to produce acid rain |
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Where do atmospheric pollutants go ? Carbon dioxide |
used by plants to photosynthesis, dissolves in rain water and in sea water |
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How can pollution caused by power stations that burn fossil fuels be reduced ? |
1. Using less electricity 2. removing sulfur from natural gas and fuel oil 3. removing sulfur dioxide and particulates from flue gases emitted by coal- burning power stations |
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How is the acid gas sulfur dioxide removed from flue gases by wet scrubbing ? |
1. using an alkaline slurry e.g. a spray of calcium and water 2. using sea water |
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What is the one way of producing less carbon dioxide? |
To burn less fossil fuels |
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How to reduce pollution caused by exhaust emissions from motor vehicles? |
1. burning less fuel e.g. more efficient engines 2. using low sulfur fuels 3. using catalytic converters 3. adjusting the balance between pubic and private transport 4. having legal limits to exhaust emissions( MOT test) |
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Advantages of biofuels instead of fossil fuels ? |
1. renewable (made from plants and waste) 2. only produce carbon dioxide and water when burned 3. Carbon neutral (plants take in as much oxygen as is given out) |
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Disadvantages of biofuels instead of fossil fuels ? |
1. Large amount of deforestation to grow plants for biofuels - species loosing their natural habitats |
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Advantages of electricity instead of fossil fuels ? |
batteries 1. electric cars produce no exhaust gases |
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Disadvantages of electricity instead of fossil fuels ? |
1. electricity to charge the battery is made by buying fossil fuels in a power station |
