Some individual elements prominently increased in number and diversity of compounds during this period, as is the case of B, F, Si, P, Sc, and Ge, showing similar patterns to organogenic elements. C compounds indeed contributed to a large extent to the revival of these element's chemistry (SI Fig. ), which in turn had an impact on the periodic system. In particular, the surge of F compounds, whose ratio of organic to inorganic compounds was above 100 by 1980, led to the splitting of the large family of H and non-metals, observed since the turn of the 20 th century (Fig. ). Thus, by 1958 this family gave place to the current fragments of chalcogens {S}, {Se, Te}; organogenic elements {H, C, N, O}, and to the parallel belonging of H to halogens and N: {H, N, F, Cl, Br, I}. The "modern age of fluorine chemistry" , as it has been called the blossoming of F chemistry after WW2, involved Fowler's perfluorination of hydrocarbons , as motivated by warfare research ; Simon's electrochemical fluorination , only disclosed after WW2 ; Fried's report of medicinal fluorinated compounds ; the discovery of fluorinated noble gases ; and the further perfluorination methods by Margraves . Thus, the role of organogenic elements, especially of C, in the chemistry of several elements in this post-war period, not only led to a surge of organogenic compounds and of their diversity (resulting from combinations with non traditional organogenic elements) but to the appearance of new similarities determining the shape of the periodic system in the period (Fig. ). Figure : Snapshots in the evolution of the periodic system. Periodic tables representative of each period in history. Families of similar elements shown in each table summarise the patterns shown in Fig. , and do not necessarily imply continuity nor simultaneity of the families throughout the period.