Look at the diagram of a fuel cell used to power a motorized vehicle. A fuel cell with 2 vertical objects labeled A and B connected by an electrical wire through a circle with a M in it; that circle is labeled A. There is an area between the two vertical objects, and substances flowing to, along, and away from the vertical objects and to the left and right. Which part of the fuel cell does A represent? anode cathode electrolyte motor

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.