What is the purpose of subscripts in chemical formulas

A. So the chemist can multiply the chemical formula by that number

B. To let the chemist know that the element is a noble gas

C. To indicate that the element has isotope

D. To indicate an elements proportions within a formula

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.