Which set of terms is in the proper order, from left to right, for labeling the reactants and products in this reaction?
H3PO4 + 3KOH
3H2O + K3PO4

B. Acid, base, water, salt

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.