How can you distinguish A from B? In this lab, you will do experiments to identify types
of changes. Using the question format you learned
(shown above), write an investigative question that
you can answer by doing these experiments.

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.