Henry Moseley said this quote

“ In the last four days I have got the (results) given by Tantalum, Chromium, Manganese, Iron , Nickel, Cobalt and Copper ... The chief result is that ... the result for any metal (is) quite easy to guess from the results for the others. This shews that the insides of all the atoms are very much alike, and from these results it will be possible to find out something of what the insides are made up of. ”