Question #a81ec

1 Answer
Jul 11, 2016

Answer:

It is due to the relative abundances of its isotopes

Explanation:

There are two principal Chlorine isotopes. About 75% of Chlorine atoms have a relative atomic mass of 35 and 25% have a relative atomic mass of 37.

Hence in a sample of Chlorine, the average relative atomic mass would be:
#(75% times 35) + (25% times 37)=35.5#