17400 | Mendeleev focused on abstract elements, not simple substances, so he got to their essence [Mendeleev, by Scerri] |
17401 | Mendeleev had a view of elements which allowed him to overlook some conflicting observations [Mendeleev] |
12450 | The periodic table not only defines the elements, but also excludes other possible elements [Azzouni] |
17480 | Generally it is nuclear charge (not nuclear mass) which determines behaviour [Hendry] |
17395 | Elements were ordered by equivalent weight; later by atomic weight; finally by atomic number [Scerri] |
17410 | Moseley showed the elements progress in units, and thereby clearly identified the gaps [Scerri] |
17406 | Moseley, using X-rays, showed that atomic number ordered better than atomic weight [Scerri] |
17408 | Some suggested basing the new periodic table on isotopes, not elements [Scerri] |
17412 | Elements are placed in the table by the number of positive charges - the atomic number [Scerri] |
17414 | Pauli explained the electron shells, but not the lengths of the periods in the table [Scerri] |
17413 | Elements in the table are grouped by having the same number of outer-shell electrons [Scerri] |
17416 | Orthodoxy says the periodic table is explained by quantum mechanics [Scerri] |
17417 | To explain the table, quantum mechanics still needs to explain order of shell filling [Scerri] |
17419 | Since 99.96% of the universe is hydrogen and helium, the periodic table hardly matters [Scerri] |
17422 | The best classification needs the deepest and most general principles of the atoms [Scerri] |
17466 | Mendeleev systematised the elements, and also gave an account of their nature [Weisberg/Needham/Hendry] |
17603 | Chemistry just needs the periodic table, and protons, electrons and neutrinos [New Sci.] |