Describe how to calculate the average atomic mass for the following element. Isotopes: % Abundance:

neon-20 90.00%

neon-22 10.00%

Average atomic mass = 20.2 amu

Explanation:

Given data:

Average atomic mass of neon = ?

Abundance of Ne-20 = 90.00%

Abundance of Ne-22 = 10.00%

Solution:

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass  = (90.00×20)+(10.00×22) /100

Average atomic mass =  1800 + 220 / 100

Average atomic mass = 2020 / 100

Average atomic mass = 20.2 amu.

a is the correct answer