Question

An element with atomic mass z has two isotopes having atomic masses (z-1) and (z+2). Find out the percentage abundance of heavier isotope.

Answer 1

z=x(z+2)+(1−x)(z−1)

z=xz+2x+z−xz−1+x

0=3x−1⟹x=1/3

Therefore, the abundance of the heavier isotope is 33.3%