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Explain how a compound such as Magnesium Oxide has a high melting point and conducts electricity when molten

A substantial amount of energy is required to break the strong ionic bonds between the ions Mg^2+ and O^2-. While in a solid state the molecular structure is rigid and does not have any free or mobile ele...

Answered by Jack J. • Chemistry tutor

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Jill and four friends go camping together for 5 days. The friends share the cost of the trip equally. These costs are: £120 for fuel, £58 for food, £100 for equipment and £207 for activities. How much does Jill have to pay for her share of the costs?

The first thing we need to realise that the cost of the trip is going to be split between 5 people (Jill + 4 friends). As they are all sharing the cost of the trip equally, we need to find the total cost ...

Answered by Lauren D. • Maths tutor

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how do I solve the equation x^2 + 7x + 11 = 0, to 3dp?

This is a quadratic equation and there are three ways to solve one. This question specifies that the answer should be left to three decimal places. This tells you that you can not factorise, as your...

Answered by Jamie D. • Maths tutor

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Work out 2 3/4 x 1 1/2. Give your answer in terms of a mixed fraction in simplest form.

Step one: As the fractions are mixed fractions we need to convert them into top heavy fractions to multiply. 2 3/4 is equivalent to 11/4 ( as 2 3/4 = 4/4 + 4/4 + 3/4 = 11/4). 1 1/2 is equivalent to 3/2 (a...

Answered by Megan B. • Maths tutor

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1.1 Write out the base sequence of the complimentary strand of DNA for the following DNA sequence (ATGGCTACG) (2 marks). 1.2 How many amino acids does the DNA sequence code for? (1 mark)

1.1 Answer: TACCGATGC (T is complimentary to A and C is complimentary to G)1.2 Answer: 3 amino acids (3 DNA bases code for 1 amino acid and there are 9 DNA bases in the sequence (9/3=3))

Answered by Siobhan L. • Biology tutor

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