Atomic number and mass number
2 marks · EasyAn atom has 13 protons and 14 neutrons. Calculate the mass number of this atom.
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27
Common mistakes: Adding electrons or only giving the number of protons
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Marking points
M1 · 1 mark · Adds protons and neutrons (13 + 14)
A1 · 1 mark · Arrives at correct mass number: 27 (follow-through)
Worked solution
The mass number is 27.