mass number
noun
Definition of mass number
: an integer that approximates the mass of an isotope and designates the number of nucleons in the nucleus
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1923
First Known Use of mass number
1923
Medical Dictionary
mass number
noun
Medical Definition of mass number
: an integer that approximates the mass of an isotope and that designates the number of nucleons in the nucleus the symbol for carbon of mass number 14 is 14C or C14—compare atomic mass
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Britannica.com: Encyclopedia article about mass number
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