Martian table is believed to be the most important tool used by chemists. On this table, it was found out that the properties of the elements differ. It was Dmitri Mendeleev and Henry Moseley who arranged the first periodic table and later arranged in another manner, respectively. Dmitri arranged the elements according to the atomic mass in which way, all same elements are grouped together. The latter, Moseley, arranged the elements according to the increasing number of atoms.