There are such strong correlations between numerous atomic parameters, physical and chemical, that the term "electronegativity" has the effect of integrating them into a single dimensionless number between 0.78 and 4.00. Consequently, the electronegativity of an element can be used to predict/describe/model much of its empirical physical character and chemical behaviour. 16 Natural system basis. Earlier, Jensen (1986) had suggested, with some caution, that any significant typology of the elements had to be based on a "natural system" of some sort, that is, it should arise naturally or spontaneously from a study of the elements' properties rather than being based on some artificial or arbitrarily selected criterion or theoretical preconception. 17