Question

The average atomic mass of nitrogen is 14.0067. The atomic masses of the two stable isotopes of nitrogen.^14 N and^15 N, are 14.003074002 and 15.00010897 amu, respectively. Use this information to determine the percent abundance of^14 N. % Determine the percent abundance of^15 N. %

Answer 1

The answer to your question is Abundance N-14 = 99.63%

Abundance N-15 = 0.37%

Step-by-step explanation:

Data

Average atomic mass = 14.0067 amu

N-14 = 14.003074002

N-15 = 15.00010897

Abundance N-14 = ? x

Abundance N-15 = ? 1 - x

Formula

Average atomic mass = (mass of N-14)x + (mass of N-15)(1 - x)

Substitution

14.0067 = 14.003074002x + 15.00010897(1 - x)

Solve for x

14.0067 = 14.003074002x + 15.00010897 - 15.00010897x

14.0067 - 15.00010897 = 14.003074002x - 15.00010897x

-0.9934 = -0.99703x

x = -0.9934 / -0.99703

x = 0.9963

Conclusion

Abundance N-14 = 0.9963 x 100 = 99.63 %

Abundance N-15 = 1 - 0.9963 = 0.0037 x 100 = 0.37 %