why is the atomic mass of strontium not a whole number
Why is the atomic mass of a element not a whole number like its atomic number and mass number? An element's atomic mass is not an integer (a whole number) because it is the average mass of all of the element's isotopes (elements that have different amounts of neutrons e â¦ ffecting the mass number of an element). For example, oxygen has 16.01 as its atomic mass.