How is the periodic table organized?
the periodic table is arranged based on atomic numbers. the origin was from Mendeleeve, who mistakenly arranged the elements by their weights. but the mistake was minor cuz there are only 3 pairs of elements were not in the right order: (1) Ar and K, (2) Co and Ni, and (3) Te and I. his contribution was tremendous. Mendeleeve found that certain main group elements behaved in a similar mannar chemically, he arranged those from top to bottom based on the mass. that’s the Group we have today. the group arrangement started out based on reaction properties. now we know better with the electron configuration, elements with the same number of electrons in the outermost shell behave similarly.
