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So, what actually is a mole?

A mole is simply a unit of measurement of any substance that contains as many atoms as there are in 12 grams of Carbon-12. Why Carbon-12? Carbon-12 is the standard by which we compare the mass of any other m...
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Answered by Patrick Q. • Chemistry tutor
4767 Views

I'm doing GCSEs, isn't it too early to be thinking about applying for medicine?

Simply, no. Whilst it is imperative to keep an open mind when it comes to what degree you wish to study in university medicine often differs from other subjects. Although many subjects are very difficult to ...
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3322 Views

How do I find the root of a quadratic equation?

Usually the easiest way to find the root of a quadratic is to factorise it so you have something a form similar to - (x+2)(x-1)=0. From here you need to find a value for x that makes each bracket equal to ze...
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Answered by Nicky F. • Maths tutor
6212 Views

When should I use the preterite and the imperfect form of the past tense?

In general the preterite is used when something has been completed. If an action has a definite start and end then you should be using the preterite, this can be both if it is something that happened once or...
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Answered by Nicky F. • Spanish tutor
4207 Views

What is Natural Selection?

Natural Selection is the accepted theory of evolution first postulated by Charles Darwin and can be thought of as 'survival of the fittest'. It is the process by which a species gradually evolves through tim...
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Answered by Ellie W. • Biology tutor
6111 Views