Question

One of the following properties was originally used to arrange elements in the periodic table but is no longer used to organize the modern version which property fits the description

Answer 1

atomic mass

Step-by-step explanation:

Answer 2

atomic weight or atomic mass.

Step-by-step explanation:

The development of periodic table starts from the Dobereiner's law of triad where he arranged the elements based on the average of atomic weight of two elements. the middle element was supposed to one with the atomic weight average of the two other elements.

Then the Newland law of octave was proposed where he observed the changes in the periodic trend based on atomic weight after seven elements.

Later Mendleev arranged the elements based on atomic weight only.

Thus the answer is atomic weight or atomic mass.

In modern version we use atomic number to arrange elements.