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Explain how chromatography is used to separate components in a mixture.

Chromatography separates components in a mixture according to their solubility in the mobile phase and their adsobance to the stationary phase. The mobile phase is the part of the chromatography set up that ...
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Answered by Immy C. • Chemistry tutor
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GSCE: How is a delta formed? (5 marks)

A delta is formed in the lower course of a river when the river reaches the sea, or another still body or water such as a large lake. The river slows down and loses energy as there is now no limiting chanel ...
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Answered by Caitlin B. • Geography tutor
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Explain why the price elasticity of demand for two products may vary.

Price elasticity depends on several other components: Availability of substitutes The proportion of a consumer's disposable income which the products account for Whether the products are addictive (consumers...
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Answered by Thomas B. • Economics tutor
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How do I integrate ln(x), using integration by parts?

This is a common question among A-Level Maths students, as integration by parts requires 2 things: 1. Something to integrate ; 2. Something to differentiate. In ln(x), we can immediately see that ln(x) is th...
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Answered by Mustafa K. • Maths tutor
4279 Views

How do alveoli create a surface for efficient gas exchange?

This kind of question is extremely common in A level biology, they want you to explain a system and apply your knowledge of biological principals to it. To understand alveoli we need to understand the concep...
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Answered by Matthew C. • Biology tutor
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