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Explain how volcanic eruptions occur at destructive plate margins (4 marks usually).

Oceanic crusts are forced beneath the continental crust at a subduction zone because they are denser. Heat produced by friction turns the sinking oceanic plate into magma. This then tries to reach the surfac...
GE
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How does the structure of the grana optimise its function?

The grana is made up of stacked thylakoid membranes which give a larger surface area upon which the photosystems and chlorophyll can trap light energy. The space within the membrane stack allows proton movem...
SM
Answered by Sophie M. • Biology tutor
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Name two advantages and disadvantages of hormonal contraception?

One advantages of hormonal contraception are that, when used properly i.e. taken on time and regularly, they are more effective than physical barrier contraceptives such as condoms or diaphragms. However the...
SM
Answered by Sophie M. • Biology tutor
4744 Views

Describe two examples of the increased power of the state during World War One (4)

'Describe' questions are looking for historical, contextual, knowledge - tailored specifically to the question.For example the examiner will have hundreds of papers to mark and they are looking for specific ...
JH
Answered by James H. • History tutor
3003 Views

Complete the balanced equation for the overall reaction in a hydrogen fuel cell. _ H2 + ___ > _ H2O

Hydrogen fuel cells are really important as they can be used to power electrical cars, so it's something that a lot of scientists are looking into at the moment. We need to balance this equation, so we need ...
KB
Answered by Kyra B. • Chemistry tutor
9413 Views