Explain: In a physical change, like changing state from a solid to a liquid, the substance itself doesn’t really change. In a chemical change, new substances are created from the old substances. Are the atoms and mass that make up these new substances created, destroyed, or rearranged? In a chemical reaction atoms and mass are…

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.