Science in Action

This year is the  184 th birthday of Dmitri Mendeleev , born 8 th Feb 1834.  The story of the periodic table that he initiated is  a nice example of Science in Action and illustrates many aspects of how modelling & science relate.   I will try and tease out some of this relating over time. But first an initial look at some of his modelling      Picture courtesy The Royal Society and Facebook  The Mendeleev table, fig 1, dates from 187 when there were only  66 known elements. A table from 2016, fig 2,  contains 118 elements. Fig 1  Mendeleev's Periodic Table, 1871 Both tables show the symbols and weights of the elements (fig 2 also includes the names of the elements),  and the elements are organised in rows and columns. The columns group elements with similar chemistry. This is made explicit in the Mendeleev table by showing, symbolically, how the element combines with oxygen and with hydrogen in each group label. We can also see, in both tabl