chemist, John Newlands had the idea of arranging chemical elements in order
of their relative atomic masses and he arranged his elements in columns.
However, Russian chemist,
Mendeleev greatly improved on Newlands' idea and convinced other chemists
to use it, so Mendeleev has been credited with the invention of the periodic
Mendeleev came up with his first version of the periodic table in 1864,
since then more than 700 versions of the table have been proposed. (see
Development of the Periodic Table)