Mendeleev arranged the elements in his Periodic Table primarily by relative atomic mass, but he swapped the positions of certain elements, such as tellurium and iodine.
Why did Mendeleev make these swaps?
To ensure elements with similar chemical properties were placed in the same group.
To correct errors in his measurements of their atomic masses.
To group elements according to their physical states at room temperature.
To arrange the elements in order of their reactivity with water.