A 2.00 mL of substance A has a density of 18.4 g/mL and a 5.00mL sample of substance B has a density of 35.5 g/mL. Do you have an equal mass of Substances A and B.

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.