Question

give a clear explanation for fractional atomic mass with example

Answer 1

The atomic masses of most elements are fractional because they exist as a mixture of isotopes of different masses.Most elements occur as a mixture of isotopes of different masses. The fractional atomic masses arise because of this mixture.

Answer 2

atomic mass of an element is the average of atomic masses of all the
isotopes of an element and this is sometimes fractional like chlorine-35.5 as it has isotopes of mass 35 and mass 37 in different ratios