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Elements and Compounds
Atoms and Atomic Structure

What is the mass number of an element?


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April 21, 2016 6:31AM

The mass number of an element is the total mass of atoms in an element (i.e protons, electron and neutrons).

If you were to look on a periodic table element square the mass number is the number above the element letter while the number below is the atomic number

E.g. If you look on a periodic table the mass number of Oxygen (O) is 16.0

mass number is the atomic mass of a particular isotope