Where did the periodic table come from

In 1869 a Russian chemist called Dmitry Mendeleev published a regular table just five years after John Newlands introduced his Law of Octaves. Mendeleev also arranged in the order of relative atomic mass elements known at that time, but he did some other things, making his table much better.

In 1869, just five years after John Newlands put forward his Law of Octaves, a Russian chemist called Dmitri Mendeleev published a periodic table. Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he did some other things that made his table much more successful.

i have no clue hope you find the answer

fe 55.85 g/mol and h2o 18.02 g/mol.