Suppose the element A contains three isotopes, 86A (atomic mass 85.909 u, abundance 16.19%) 87A (atomic mass 86.908, abundance 7.00%) and 88A (atomic mass 87.906 u). What would be the atomic mass of A that would appear in the periodic table?
(A1 x %A1) + (A2 x %A2) + (A3 x (1-(%1 +%2)) = answer
The Attempt at a Solution
16.19% + 7.00% = 23.19%
100% - 23.19% = 76.81% --> so that would be the 88A abundance % right?
then I'm confused from there. Please help