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Explain how the electron pair repulsion theory can be used to deduce the shape of, and the bond angle in, NH3.

Nitrogen has 5 valence electrons in its outer shell. Each Hydrogen has 1 valence electron in its outer shell, so the 3 Hydrogens donate 3 electrons in total. This gives 8 valence electrons in total. We can t...
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Answered by Matthew N. • Chemistry tutor
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How much work experience do I need?

It is important to stress that universities realise getting work experience is hard, therefore a lack of work experience should not be counted against you.In my experience one week in primary healthcare ie a...
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Explain, in terms of sub-atomic particles, why the mass number of a magnesium atom is 24.

On the periodic table, Magnesium has the symbol 12 Mg 24 , where 24 is the mass number and 12 is the atomic number. The atomic number is the number of protons found inside an atom, while the mass number tell...
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Answered by Matthew N. • Chemistry tutor
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What is an enzyme?

An enzyme is a type of protein that catalyses reactions that occur in the body. In many cases they are essential in order to allow reactions to occur under physiological conditions. There are many different ...
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Answered by Rohin A. • Biology tutor
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What is the difference between DNA transcription and translation?

DNA is used to code proteins. This requires two steps: transcription and translation.Transcription is the conversion of double stranded DNA into a single stranded mRNA molecule. DNA nucleotides bind to their...
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Answered by Rohin A. • Biology tutor
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