why atomic mass is in fraction while mass number is in whole number
Answers
But due to existence of isotopes there are two different atoms of same element with different mass number by same atomic numbers.
Atomic Mass is calculated by taking the weighted mean of all isotopes according to the amounts of them present on earth. This creates fractions.
Hence Atomic can be fractional but Mass number is always a whole number.
Answer:
Atomic mass of an element is not a whole number because It contains isotopes.
For example, chlorine has two isotopes .
Cl with natural abundances in the approximate ratio of 3:1. Hence, the average atomic mass of chlorine is approximately 35.5 g/mol.
Explanation:
Mass number is the sum no. of neutrons and no. of protons. Now since there can't be a fraction of either one of them in any atom, the mass number is a whole number.
But due to existence of isotopes there are two different atoms of same element with different mass number by same atomic numbers.
Atomic Mass is calculated by taking the weighted mean of all isotopes according to the amounts of them present on earth. This creates fractions.
Hence Atomic can be fractional but Mass number is always a whole number.