The two isotopes of chlorine are latex: \begin{matrix}35\\17\end{matrix}cl3 5 17 c l and latex: \begin{matrix}37\\17\end{matrix}cl3 7 17 c l . which isotope is the most abundant?

The percentage abundance of and isotopes are 77.5% and 22.5% respectively.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

  .....(1)

Let the fractional abundance of isotope be 'x'. So, fractional abundance of isotope will be '1 - x'

Mass of isotope = 35 amu

Fractional abundance of isotope = x

Mass of isotope = 37 amu

Fractional abundance of isotope = 1 - x

Average atomic mass of chlorine = 35.45 amu

Putting values in equation 1, we get:

Percentage abundance of isotope =

Percentage abundance of isotope =

Hence, the percentage abundance of and isotopes are 77.5% and 22.5% respectively.