Sodium has only one naturally occurring isotope, sodium-23. Using the data presented in Table 20.3, explain how the molecular mass of sodium is 22.98976 amu and not the sum of the masses of the protons, neutrons, and electrons.

01 2 3 3 04 03 04 04 84 86 88 90 90 01 2 9 9 Co Ni Po Po Ra Ra Th Pa U 12 00 18 94 31 00 36 92 51 94 0-1 1 1 2 3 3 4 6 7 9 0 2 3 5 111-15 5 1 0111233 46790123626 1011112233455668 2 enpH He Li Be B C Cr Fe