Question

http://media.education2020.com/evresources/652-02-03-02-00_files/i0240000.jpg

Based on the information above, do you think that fluorine has common isotopes? Justify your answer.

Answer 1

I think you look at the mass. Since the mass of an element in the periodic table is calculated by multiplying the percentage abundance of each isotopes with their masses and adding them together, I would expect to see decimal places if there are isotopes. Makes sense?

Answer 2

Example of what I said: http://chemistry.about.com/od/workedchemistryproblems/a/atomabundance.htm