Question

The nucleodic masses of ${}^{14}\text{N}$ and ${}^{15}\text{N}$ are mixed to give atomic mass of 14.1. What is the ratio of the two isotopes as a whole number.

Answer 1

Let the ratio be $x:1$

$\therefore x\times 14+1\times 15=14.1(x+1)$ (Law of average)

$\therefore x=9$

Hence the ratio is $9:1$ or $9$