The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
256 are needed because 32x1=32 that means the ratio would be 32:256 because 8 x 32 = 256 The final ratio would stay the same as 1:8 though because it would be simplified. Hope this helped.