2 bottom) seem to lose this feature while they position helium in a traditional way above neon (Scerri 2009). Scerri’s modifications of the Table (both “symmetric traditional”, and LSPT, for the latter see Fig. This version strongly emphasizes the electronic structure of isolated atoms in the gas phase, and the fact of existence of the s, p, d, and f blocks of the Periodic Table. Specifically, the so-called left-step form of the periodic table, LSPT (Janet 1928a, b, 1929 Tarantola 2000 Scerri 2005a Stewart 2010) organizes elements according to the orbital filling (instead of theoretical maximum valence) and is sometimes used by physicists (Fig. However, this has not necessarily been the case, if other historically important formulations of the Periodic Table are taken into consideration.
neon, argon, krypton, xenon, radon (and Ununoptium, i.e. In all versions routinely used today in the universities worldwide, helium, the Z = 2 element, is been placed together with other “noble” gases, i.e. It may seem that with the naming of the last superheavy elements in 2016, the history of the formulation of the Periodic Chart is closed, or at least it will rest until the new Period is opened due to a synthesis of a Z > 118 element (Seaborg 1969 Pyykkö 2011). This version of the Table survived in the main didactic room to this day, except for a few elements being given their new IUPAC-recommended names (Francl 2009). Now, the old Group VIII encompasses three modern Groups: 8, 9 and 10. Finally, the freshman years of the 1990s brought another, more subtle, modification: the giant Periodic Table depicted in the Grand Aula of the Chemistry Faculty of the University of Warsaw corresponds to a long version, with noble gases placed in the last Group of the chart, the Group numbering now running from 1 to 18 in Arabic rather than Roman numbers (Fig. Here, the A and B Groups still persisted. On the other hand, the Periodic Table recommended to this author during education in the comprehensive school a decade later was the so-called long version (LPT), with the transition metal elements clearly separated from the main group ones (Fig. Here, noble gases stand out as Group 0, to emphasize lack of room for them in the original Mendeleyev’s formulation this happily coincides with their null (or weak at best) bond-forming ability. This version follows to some extent the early formulation by Mendeleyev, and introduces Group VIII containing Fe, Co, Ni, and their heavier analogues. The traditional depiction of the periodic system, which has been taught to this author in primary school in the 1980s, has been the so-called short version (SPT), with the division to A (main group) and B (transition metal) Group elements (Fig.