Which is a characteristic of a decomposition reaction?

A kind of chemical reaction in which a single compound dissociates into two or more elements or novel compounds is known as a decomposition reaction. These reactions usually comprise a source of energy like light, heat, or electricity, which dissociates the bonds of compounds. The reaction can be demonstrated by the general equation, that is, AB = A + B. The example of a decomposition reaction is the dissociation of water into oxygen and hydrogen.

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.