Question

Oxygen exist in two isotopic form 16x8 and 18x8 with the average atomic mass of 16.2u.find the percentage of each isotope

Answer 1

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Answer 2

Lets take the percentage of the  isotope of  16 8 X as  --> x %

So , the percentage of the  isotope of 18 8X ---> (100 - x) %

We are given the average atomic mass as 16.2

 × 16 +  × 18 = 16.2

+ = 16.2

-2x + 1800 = 16.2 × 100

-2x + 1800 = 1620

-2x = 1620 - 1800

-2x = -180

x = \frac{-180}{-2}

x = 90 %

Therefore , percentage of isotope of 16 8 X = 90 %

percentage of isotope of 18 8 X = 100 - x = 100 - 90 = 10 %

Hope it helps ♥️