Question 253 of 991 in Principles of Chemistry

The periodic table

2 marks · Easy

An atom of aluminium has a mass number of 27 and an atomic number of 13.

Calculate the number of neutrons in an aluminium atom.

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14 (±0)

Common mistakes: 27 + 13 = 40; using atomic number instead

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Marking points

M1 · 1 mark · Attempts correct calculation: 27 - 13.

A1 · 1 mark · Correctly gives final answer 14.

Worked solution

So there are 14 neutrons in an aluminium atom.

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