Characteristics of a mixture?

Characteristics of mixtures
The substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation.
There is little or no energy change when a mixture forms (see Enthalpy of mixing).
Mixtures have variable compositions, while compounds have a fixed, definite formula.

Hello thereone of the following properties was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version. which property fits this description? answer: atomic mass  was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

That is a lot of moles that you have