Examples of working out abundances from the Ar

Examples of working out Abundances

Naturally occuring potassium consists of K-39 and K-41. Calculate the % of each isotope present if the average is 39.1.Let % K-39 = X      % K-41 = (100-X)Ar=39.1= (39 x X) + (41 x (100-X)                              1003910= 39X + 4100 - 41X190= 2X190 = X 295 = X  Therefore:  95% = K-39                    5% = K-412. Ar of Ne is 20.0. The isoptopes and Ne-20 and Ne-22. Find there % abundances.Ar= 20.2= (20 x X) + (22 x (100 - X))                               1002020= 20X + 2200 - 22X-180= -2XX = 90Therefore: Ne-20 = 90%                  Ne-22= 10%

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