Element X has three istotopes, X⁹⁵, X⁹⁶, and X⁹⁸. Element X has an atomic mass of 96.344u. If X-98 has a mass of 98.0001u and an abundance of 19.8%, what are the abundances of X-96 (mass of 95.9988u) and X-95 (mass of 95.0011u)?

Answer 1

We know X-98 is 98.0001 and 0.198; therefore, 1-0.198 = 0.802 must be the fraction for 96 and 95.
Let X = fractional abundance of X-96
Then 0.8020-x = fractional abundance of 95.
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98.0001(0.198) + 95.9988(x) + 95.0011(0.802-x) = 96.344
Solve for x.