If atomic weight and atomic mass are different, why does the periodic table list the atomic mass as if it was the atomic weight?

Question

I’m so confused with these two. I know they are different terms but the periodic table shows atomic mass when to my understanding it should be the atomic weight because it’s taking into account their isotopes

In: Chemistry

Answer 1

Some do. The *only* thing standardized is the periods & groups, and even those may be presented differently (if you want to “correctly” display the lathanides & actinides). Most tables I have seen have the standard atomic weight listed, not the atomic mass. I have seen some with the atomic weight listed, *and* the atomic mass of the most-common isotope.