Chlorine exists in two isotopic forms ³⁵ Cl , ³⁷ Cl . If average atomic mass of chlorine is 35.5 , what is the percentage abundance of these isotopes respectively?

Step-by-step solution

Average atomic mass atomic mass of ³⁵ Cl percentage = + atomic mass of ³⁷ Cl percentage 100 Let the % abundance of ³⁵ Cl isotope =x . % abundance of ³⁷ Cl isotope =100-x . Average atomic mass =35.5 From formula, Average atomic mass aligned & = 35 x+37 (100-x) 100 =35.5 & 35 x+3700-37 x=35.5 100 & -2 x=-3700+3550 & 2 x=150 & x=75 aligned Percentage abundance of ³⁵ Cl =75 % and ³⁷ Cl =(100-75)=25 %