Question

Which 2 elements would be out of order in the periodic table if they were arranged by atomic mass instead of atomic number?

Answer 1

Tellurium and Iodine

Step-by-step explanation:

Iodine has a lower atomic mass than Tellurium despite it having a higher atomic number. This means if the periodic table were ordered by atomic mass, Iodine would be placed before Tellurium despite having a greater atomic number.