Which type of equation can also be considered an oxidation-reduction reaction?

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

can you list the answers so i can answer

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.