Question

Why is the mass number of an element always a whole number?

Answer 1

hy mate°°

because Atomic mass is never an integer number for several reasons: Theatomic mass reported on a periodic table is the weighted average of all the naturally occuring isotopes. Being an average it would be most unlikely to be a whole number. The mass of an individual atom in atomic mass units is the mass relative to carbon-12.

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hope it helps

Answer 2

Answer:

because the mass number is the sum of protons and neutrons present in atomic nucleas  and atom can not have fractinal  protons and neutrons so it is always a whole number.

Explanation: