Question

Given that the percentage abundance of the isotope ${}_{10}^{20}Ne$, is 90% and that of the isotope ${}_{10}^{22}Ne$ is 10%, calculate the average atomic mass of neon.

Answer 1

Here, 90% means 90 out of 100, that is equal to 90/100. Similarly, 10% is equal to 10/100.

Average atomic mass of Ne = $(\frac{90}{100}\times 20amu)+(\frac{10}{100}\times 22amu)$

= 18 amu + 2.2 amu

Average atomic mass of Ne = 20.2 amu