Question

Given that the abundances of isotopes, ${}^{14}N$ and ${}^{15}N$ are 99.63% and 0.37% respectively, the average atomic mass of $N$ is:

• A. 14.0037 u
• B. 14.37 u
• C. 14.05 u
• D. 14.0025 u

Answer 1

The correct option is A 14.0037 u

The average atomic mass of $N$ will be
$=(14\times 0.9963+15\times 0.0037)$ u
= 14.0037 u