Question #a535f

1 Answer
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#-""_17^35Cl and ""_17^37Cl#

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

The atomic mass of #Cl->35.453" g/mol"#

So weighted average atomic mass

#(xxx35+(100-x)37)/100=35.453#

#=>35x-37x=3545.3-3700=-154.7#

#x=154.7/2=77.35#

So Abundance

#""_17^35Cl->77.35%#

and

#""_17^37Cl->22.65%#