The periodic table . a. is arranged by atomic mass
b. was developed by early alchemists
c. is arranged by the number of protons
d. is divided into vertical periods and horizontal groups

It's either a or c I'm pretty sure but i don't know which one

both a and c

Explanation:

it shows the mass of the element along with protons

A. is arranged by atomic mass   and/or number

Explanation:

hope i helped

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.