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How do you rationalise the denominator?

Defintions Rationalising the denominator means rewriting a fraction so that the bottom only contains rational numbers. Remember: A rational number is one that can be made by dividing two whole numbers (e.g. ...
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Answered by John O. • Maths tutor
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What is cancer and what are the most common types?

Cancer: what is it? A cancer happens when cells begin to divide out of control. Benign tumours are growths of abnormal cells which are contained in one area, usually within a membrane. They do not invade oth...
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Answered by Appitha A. • Biology tutor
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Find the point of intersection between two lines y=2x+4 and 2y+3x=1:

Initially drawing a diagram of the two lines helps to establish whether values should be positive or negative and gives a rough approximation of where the answer may be: By doing this we see the point of int...
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Answered by Michael W. • Maths tutor
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How do you calculate the pH of a weak acid?

Lets say we have 0.89 mol dm-3 of CH3COOH, a weak acid, with a ka of 1.7X10^-5.We want to find Ph, but to do this we first need to know [H+] because PH = -log10[H+].Because CH3COOH is a weak acid, it only pa...
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Answered by Amy H. • Chemistry tutor
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What's the difference between covalent and ionic bonding?

Covalent bonding happens when two molecules share a pair of electrons. For example in hydrogen chloride (HCl). Ionic bonding is when two oppositely charged ions are attracted to each other to form a lattice....
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Answered by Isobel S. • Chemistry tutor
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