The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes 
and 
in the sample?
It is given that the average atomic mass of the sample of element X is 16.2 u.
Let the percentage of isotope be y %. Thus, the percentage of isotope will be (100 - y) %.
Therefore,
Therefore, the percentage of isotopeis 10%.
And, the percentage of isotopeis (100 - 10) % = 90%.
