Why are the atomic masses of some elements are in fraction and not in whole numbers - Science - Structure of the Atom

Question

Why are the atomic masses of some elements are in fraction and not
in whole numbers ?

Akanksha Jain · Accepted Answer

Kindly refer to the following link:
https://www meritnation
com/ask-answer/question/why-atomic-mass-of-some-element-are-in-fraction/atoms-and-molecules/447243

Why are the atomic masses of some elements are in fraction and not in whole numbers ?