How much heat ,in joules, is needed to vaporize and 18.0 gram sample of water at 100°

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

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.