N2(g) + 3H2(g) + 2NH3(g) reactant molecule(s)

The equilibrium system described by this equation has _ reactant molecule(s)

and _ product gas molecule(s).

3 1/4 %

explanation:

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.