What is the atomic mass of hafnium if, out of every 100 atoms, 5 have a mass of 176, 19 have a mass of 177, 27 have mass of 178, 14 have a mass of 179, and 35 have a mass of a 180?
If there are two isotopes an element
In the given problem about Hafnium, 5 isotopes have been given.
Extending the above expression to 5 isotopes
(Ensure that sum of all fractions adds to 1.
It is easy to find the fraction of each isotope in the question as total number is given as 100 atoms. Number of each isotope divided by 100)