# An element has two naturally occurring isompes widx atomic masses of 10.01 amu and 11.01 amu. The relative abundances of these elements are 19.8% and 80.2%, respectively. What is the average atomic mass of the element?

##### 1 Answer

Nov 29, 2015

#### Explanation:

Now I hope you have been exposed to the concept of weighted average;

If not here is a video

Now lets get our data;

Lets call our element x; Let its existence and abundance be divided in 100 parts

so

Total atomic mass in this isotope is;

Total atomic mass in this isotope is;

Now total number of mass units

But now the total number of parts

So all that's left is the weighted average;