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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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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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Explain why fluorine and chlorine are in the same group of the periodic table.

These elements are in the same group in the periodic table due to their electron configurations: fluorine: 2, 7 chlorine: 2, 8, 7 They both have 7 electrons in their outer shell, so therefore are both in gro...
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Answered by Mia V. • Chemistry tutor
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What is a disproportionation reaction?

A disproportionation reaction is when an element is both oxidised and reduced in the same reaction. You check this by looking at the oxidation state of the element at the begining of the reaction and then wh...
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Answered by Mia V. • Chemistry tutor
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What is Le Chatelier's Principle?

Le Chatelier's Principle states that for a reaction which is reversible, where there is a change made to the reaction conditions the equilibrium position will shift to oppose the change. In answering a quest...
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Answered by Angus T. • Chemistry tutor
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