Chapter 2, Problem 2.121SP

A sample of naturally occurring silicon consists of ${}^{\text{28}}\text{Si }\left(\text{27}.\text{9769}\right){,}^{\text{29}}\text{Si }\left(\text{28}.\text{9765}\right),$ and ${}^{\text{3}0}\text{Si }\left(\text{29}.\text{9738}\right)$ . If the atomicweight of silicon is 28.0855 and the natural abundance of ${}^{\text{29}}\text{Si}$ is 4.68%, what are the natural abundances of ${}^{\text{2}8}\text{Si}$ and ${}^{\text{3}0}\text{Si}$ ?