Question

Give one example of a pair of elements that would be placed incorrectly if they were in the order of their relative atomic masses on the periodic table. Explain why placing these two elements in the order of their relative atomic masses
would not be correct.

Answer 1

cobalt and nickel
nickel has a lower atomic mass number, but has a higher atomic number or more protons. Elements are arranged by atomic number.

Ir and Pt also