Physics GCSE
mass number
What mass number means in Physics GCSE, as defined for AQA.
Definitions of mass number
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Reference: AQA
The number written above the chemical symbol in a nuclide symbol, which differs between isotopes of an element.
The total number of protons and neutrons in an atom, written as the upper number in the nuclide symbol.
Topics that use mass number
- Mass number, atomic number and isotopes (AQA GCSE)
Related terms
- atomic number
- counting neutrons
- identity, charge and mass
- ions
- isotopes
- neutral atoms
- nuclide notation
- nuclide symbols
Using mass number in the exam
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