The value of ΔH° for the reaction below is -790 kJ. What is the change in enthalpy (in kJ) when 0.95 g of S converted into SO3?
2S (s) + 3O2 (g) → 2SO3 (g)

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.