Find iron on the periodic table. Iron has many isotopes. Based on the information given on the periodic table for iron, what isotope of iron is the most common isotope found in nature? Explain your answer.

Answer 1

The atomic weight is 55.845
So I'd say Fe55 is the most common
The heavier isotopes move the average atomic weight up a bit.

Answer 2

I disagree. I would think the most common isotope would be 56Fe with the packing fraction and other isotopes moving it down somewhat.