Question

What determines the order of placement of the elements on the modern Periodic Table?
(1) atomic number(2) atomic mass(3) the number of neutrons, only(4) the number of neutrons and protons

Answer 1

The order of placement of the elements on the modern Periodic Table is the atomic number. The answer is number 1. The rest of the choices do not answer the question above. Atomic mass gives the number of mass of an atom.