Two Elements whose atomic mass order does not match thier atomic number order

Question

Two Elements whose atomic mass order does not match thier atomic number order using periodic table

Answer 1

There are actually 3 such cases.

First, argon has a higher atomic mass than does potassium, but comes before it in the Table.

Second, cobalt has a higher atomic mass than nickel, and also appears before it in the Table.

Finally, tellurium comes before iodine yet has a higher atomic mass.