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Infection and response
Organisation
Cell biology
Biological molecules
Homeostasis and response
Responding to change (a2 only)
Energy transfers (a2 only)
The control of gene expression (a-level only)
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
Cells
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1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
Britain & the wider world: 1745 -1901
Inter-war germany
World war one
2n revolution and dictatorship: russia, 1917-1953
World war two & the holocaust
1l the quest for political stability: germany, 1871-1991
The cold war
2j america: a nation divided, c1845-1877
Medieval period: 1066 -1509
The fight for female suffrage
2m wars and welfare: britain in transition, 1906-1957
2d religious conflict and the church in england, c1529-c1570
Britain: 1509 -1745
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01/04/2023
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Q Combustion What is combustion? Combustion is another word for burning a fuel. It is an irreversible, chemical reaction. Combustion releases energy as heat, called an exothermic reaction. What is a fuel? A fuel is a substance that stores energy in a chemical store. When a fuel burns it transfers energy into the surrounds as heat (useful energy). What is a hydrocarbon? Most fuels contain hydrocarbons. It is a compound of hydrogen and carbon. The symbol for a hydrocarbon is CH4 Complete Combustion Complete combustion takes place when there is lots of oxygen. The fuel burns to form carbon dioxide and water. X Incomplete combustion Incomplete combustion takes place when there is not enough oxygen. The fuel burns to form carbon monoxide (extremely toxic), water and carbon. Advantages of complete combustion The water produced can be used in all sorts of ways useful to both human beings, animals and plants. Carbon dioxide can be useful, to an extent, by helping plants got photosynthesis. Disadvantages of complete combustion Though the carbon dioxide can have benefits for the planet, too much can contribute to climate change. Advantages of incomplete combustion. Incomplete combustion produces carbon monoxide that can be used in gas furnace, gas water heaters, wood burning stoves and more. Disadvantages of incomplete combustion. Incomplete combustion is dangerous as it produces carbon monoxide, an extremely harmful gas that can be fatal if humans inhaled it.
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