THE TIME EVOLUTION OF THE HARD AND SOFT ACIDS AND BASES THEORY - Theoretical and Computational Research in the 21st Century - page 2

1.1 INTRODUCTION
Our history says that the periodic table was written in Russian, the quan-
tum mechanics was written in German, and our understandings were in
English [1]. The present status shows that although the periodic table has
the powerful chemical organizing power, it does not follow from the quan-
tum mechanics. We are habituated in thinking and modeling in terms of
many things that are mental constructs and do not occur in the real world,
and hence do not follow from quantum mechanics. Or in other words, their
measurement and evaluation in terms of quantum mechanics are ruled out
because they are not the things of the real world, and hence have no quan-
tum mechanical operators. They occur in mind and in the domain of hy-
pothesis such as the unicorn of mythical saga [2]. They exist but cannot
be seen. We can mention many such mental constructs in the domain of
hypothesis. We mention here only two of such mythical objects. These are
the “electronegativity” and the “hardness.” If the meaning and purport and
operational significance of these two legends are withdrawn from the ped-
agogy of chemistry, there will be a total chaos in the whole of the chemical
and physical world. These two hypothetical and mental constructs are so
important descriptors deep rooted in the thinking of chemistry and physics
that scientists had to search method of their measurement through model-
ing. In fact, these are measured after reification [3], that is, suggesting and
designing certain model and then evaluation was conceived. We may refer
to the opinion of Parr et al. [4] who seem to have connected the construct
of the hardness and the electronegativity with the noumenon of Kantian
philosophy. The noumenon is an object knowable by the mind or intellect,
but not by the senses. Thus, the hardness and/or electronegativity are ob-
jects of purely intellectual discourses. Scientists have designed scales of
measurement of the electronegativity and hardness. Success lies in the fact
that the results of semi empirically evaluated data are useful in correlation
with chemical and physical behavior of atoms, molecules, and crystalline
solids.
The improvement of basic structural thinking in chemistry was often
based on empirical relations between some properties, which can be mea-
sured or can be found in the literature. The ultimate aim of chemists, till
now, is to understand and correlate the naturally occurring phenomenon.
For this purpose, chemists, rely upon the electronic structure of the funda-
mental gross building stones of the universe—the atoms.