Mendeleev's overall arrangement of elements in the periodic table is based on

Repeated patterns in the elements. 
Hopefully this helps

It is based on collumns and reactivity of the element, the ones on the far right (column 1,2 and 3) are all metals, the ones in the middle (columns 4,5,6 and 7) are physical matters and the ones on the far right (columns 8 and 9) are all gasses, hope this helps