What statement is true about the atomic mass?

The Atomic Mass of an element is the weighted average mass of its isotopes, measured in atomic mass units (amu). It reflects the number of protons and neutrons in the nucleus of an atom and is typically not a whole number due to the presence of isotopes and their relative abundances. Atomic mass is often listed on the Periodic Table and is used to determine the mass of a mole of atoms in grams.