Why aren’t the masses on the Periodic Table whole numbers?
: Why aren’t the masses on the Periodic Table whole numbers? The atomic masses on the Periodic Table are average masses for all of the isotopes of that element. Isotopes – atoms of the same element that differ only in their mass The abundance of each isotope is determined with an instrument known as a mass spectrometer. Slide 3: In a given sample of chlorine… 75.78% is Chlorine-35 24.22% is Chlorine-37 To calculate the average atomic mass, multiply each isotope’s mass by its relative abundance. Then add these up.
