why-are-atomic-masses-on-the-periodic-table-typically-not-whole-numbers

Question

Why are atomic masses on the periodic table typically not whole numbers?

Accepted Answer

They represent the average mass of all isotopes of an element.

Answer

They only consider the most abundant isotope.

Answer

They are calculated based on the number of protons and neutrons only.

Answer

They are rounded to the nearest whole number.