Question

Potassium has two naturally occurring isotopes. Potassium-39 had a relative abundance of 95.0% and potassium-40 has a relative abundance of 5.0%. Determine the average atomic mass for copper using this information

Answer 1

Assuming that the question is about potassium and not copper;

The relative atomic mass of potassium is caculated as;

$RAM=\dfrac{(39x95)+(40x5)}{100}$

$RAM= \dfrac{3705200}{100} = 39.05$