Question

[40 points] How do I find the average atomic masses of these?

Answer 1

Answer:

14.02 amu

Explanation:

The following data were obtained from the question:

Isotope A (N–13):

Mass of A = 13 amu

Abundance (A%) = 28.97%

Isotope B (N–14):

Mass of B = 14 amu

Abundance (B%) = 41.04%

Isotope C (N–15):

Mass of C = 15 amu

Abundance (C%) = 29.97%

Average atomic mass of nitrogen =?

The average atomic mass of nitrogen can be obtained as illustrated below:

Average = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]

= [(13 × 28.97)/100] + [(14 × 41.04)/100] + [(15 × 29.97)/100]

= 3.77 + 5.75 + 4.50

= 14.02 amu

Thus, the average atomic mass of nitrogen is 14.02 amu