Question

define mass number.....❤​

Answer 1

Mass number is an integer (whole number) equal to the sum of the number of protons and neutrons of an atomic nucleus. In other words, it is the sum of the number of nucleons in an atom. Mass number is often denoted using a capital letter A.

Contrast this with the atomic number, which is simply the number of protons.

Electrons are excluded from the mass number because their mass is so much smaller than that of protons and neutrons that they don't really affect the value.

Hope it helps....

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