Question

Given the following information, calculate the mass for B-11. B-10 has a natural abundance of 19.9

percent, while B-11 has a natural abundance of 80.1 percent. The mass of B-10 is 10.013 amu.

Answer 1

Mass of B-11 = 11.009 amu

Step-by-step explanation:

Given data:

Abundance of B-10 = 19.9%

Abundance of B-11 = 80.1%

Mass of B-10 = 10.013 amu

Mass of B-11 = ?

Solution:

Average atomic mass of boron is 10.811 amu.

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

10.811 = (10.013×19.9) + (x × 80.1) /100

10.811 = 199.26 + (x × 80.1)

10.811 × 100 = 199.26 + (x × 80.1)

1081.1- 199.26 = x × 80.1

881.84 = x × 80.1

881.84/ 80.1 = x

x = 11.009