Abalance is used to measure: mass weight volume density

Once the unit of mass is defined, samples of matter can be compared to the unit and thus measured.

Comparing a sample of matter to the standard unit of mass, or to its subdivision the gram, can be done

on an equal-arm balance.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.