Question

There are two naturally occurring isotopes of chlorine. 35^CI has a mass of 34.9689 amu. 37^CI has a mass of 36.9659 amu. Determine the abundance of each isotope.

Answer 1

Let abundance of Cl³⁷ = x

let abundance of Cl³⁵ = 1-x

Average atomic mass = atomic massof Cl³⁷* abundance + atomic mass of Cl^{35 *} abundance

    35.453                    = 36.9659*x +34.9689*(1-x)

      x    = 0.24

    x% = 24%

abndance of Cl³⁷ = 24%

abndance of Cl³⁵ = 76%