A better form of table

A disadvantage of the form of table currently used is that it loses completely the secondary relationships shown in the chart in Section 10.1 (i.e. between 3-valent Sc and Al, 4-valent Ti and Si, 5-valent V and P, etc.). These relationships can be shown in a pyramidal form of table as pictured below. Principal connections are indicated by blue lines and secondary coimections by red ones. 

Hull Periodic Table, as at www.hull.ac.uk/chemistry/hullptable 

You will notice that Mg is coimected to Zn by a blue line as well as to Ca. This is because Zn, Cd, and Hg are like Mg in being bivalent metals. One trivalent compound of Hg has been reported, but this is very unstable (it decomposes within a few seconds at -78 °C). The effect of this connection is to make Zn, Cd, and Hg part of main group 2M, and to shorten the transition series. This means that the zinc group should not be labelled 12T, but as a subgroup of 2M (2M ). 

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