# Question a535f

Nov 10, 2016

Atomic mass of an element is defined as the weighted average mass of atoms of an element, calculated using the relative abundance of nuclides in a naturally-occurring mass of that element.

In nature the in a mass of CHlORINE two types of nuclides are present$- {\text{_17^35Cl and }}_{17}^{37} C l$

If percent abundance of ""_17^35Cl be x% then percent abundance of ""_17^37Cl will be (100-x)%

The atomic mass of $C l \to 35.453 \text{ g/mol}$

So weighted average atomic mass

$\frac{\times x 35 + \left(100 - x\right) 37}{100} = 35.453$

$\implies 35 x - 37 x = 3545.3 - 3700 = - 154.7$

$x = \frac{154.7}{2} = 77.35$

So Abundance

""_17^35Cl->77.35%

and

""_17^37Cl->22.65%#