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.

Mass of B-11 = 11.009 amu

Explanation:

Given dа ta:

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