Why is the atomic mass of chlorine quoted on the Periodic Table NON-INTEGRAL?

1 Answer
Dec 1, 2015

All chlorine nuclei have 17 protons in their nucleus. Chlorine nuclei contain differing numbers of neutrons. The weighted average of the nuclei sum to #35.45# amu.


Isotopic breakdown of chlorine: #""^35Cl#, 75.77%; #""^37Cl#, 24.27%. These are the major isotopes and their weighted average is the quoted atomic mass.