Question

Nitrogen has 2 stable isotopes, N-15 which occurs in nature .7% of the time, and N-14 which occurs 99.3% of the time. Calculate the average isotope mass and include units.

Answer 1

14.007 amu

Step-by-step explanation:

N-15 has 15 amu, while N-14 has 14 amu.

So average isotope mass = 15(0.7%) + 14(99.3%)

= 15(0.007) + 14(0.993)

= 0.105 + 13.902

= 14.007 amu