# How would you find the percent abundance of 2 isotopes of an element, given the atomic weight and mass number of each isotope?

##### 1 Answer

Nov 11, 2015

#### Answer:

See explanation.

#### Explanation:

The average atomic mass of elements is calculated by:

For example, suppose we want to find the percent abundance of chlorine isotopes

Assume that the percent abundance of

Thus,

Solve for

Therefore, the percent abundance of