I understand that John Newland’s law of octaves was ridiculed by the scientific community as his table failed to work past calcium. I'm trying to understand how Mendeleev’s table improved on this.
On Mendeleev’s table, do all elements in the same group even past calcium exhibit similar properties? I saw on his table that potassium and copper were in the same group. Calcium and zinc were also in the same group. It seems to me that these elements have different properties.
So why was this accepted? Don't potassium and copper exhibit different properties as well as calcium and zinc? To me, it appears that both Newlands and Mendeleev's tables had elements in the same group with very different properties.