Question

Calculate the atomic mass (average) of chlorine using the given data : % ³⁵Cl ³⁷Cl Natural Abundance75.77 24.23 Molar Mass34.968936.9659

Answer 1

by using the formula

av.atomic mass= relative abundance*mass of the isotope / 100

thus we have (35*75.77+37*24.23)/ 100 which is approx 35.41 which is the atomic mass of chlorine

Answer 2

Nuclear mass of first isotope = 34.9689

Natural plenitude of first isotope = 75.77% or 0.757

Atomic mass of second isotope= 36.9659

Natural wealth of second isotope= 24.23% or 0.242

Now normal nuclear mass of chlorine = [34.9689x 0.757 + 36.9659x 0.242]/(0.757+0.242) =35.4521

So, the normal nuclear mass of chlorine = 35.4527 u.