Background: Chemical hardness is one of the most useful conceptual constructs of
chemistry and physics and this quantity is an important tool in the understanding of behavior of
Method: In the present report, we have disclosed about the effect of molecular hardness on
chemical properties like ionic character, bond length, bond force constant and melting point for
alkali halides that are among the most familiar ionic crystals. Absolute hardness values of alkali
halides have been calculated via molecular hardness equation published by us in the recent past.
Conclusion: The results obtained and graphs plotted in the study demonstrated that ionic
characters, bond lengths, bond strengths, bond force constants and melting points of alkali halides
are closely associated with their absolute hardness values.