Question

natural chlorine has isotopes Cl (Mass no.35, atomic no.17) and C (Mass no.37 and atomic no.17) in the ratio 1:3.Find the average atomic mass of natural chlorine

Answer 1

$$\begin{gathered} Averageatomicmass=\frac{x_1{M}_1+x_2{M}_2}{x_1+x_2} \\ {x}_{1}and{x}_{2}aretherelativeabundanceofthetwoisotopes. \\ {M}_{1}and{M}_{2}aretheatomicmassofthetwoisotopes. \\ Averageatomicmass=\frac{x_1{M}_1+x_2{M}_2}{x_1+x_2} \\ =\frac{{\displaystyle \frac{1}{4}}\times 35+\frac{3}{4}\times 37}{{\displaystyle \frac{1}{4}}+{\displaystyle \frac{3}{4}}}=36.5u. \end{gathered}$$