ABSTRACT
The orthogonal space of chemical reactivity represents a chemical concept which can be explained with the aid of the reactivity indices electronegativity and chemical hardness, when one considers in chemical reactivity analysis the difference between the energetic level characterizing electronegativity and the energetic gap characterizing chemical hardness. The chemical orthogonal space is based on the idea of constructing an analogy between the (3+1) D model given by the physical laws and the chemical phenomena. The reactivity indices can be used to analyze the molecular interaction mechanism in the case of a bonding complex which is chemically formed when a chemical, biological interaction occurs. The acids and bases have an important role in chemical bond and bonding theory, their characterization being a conceptual challenge for chemists for centuries. M. V. Putz determined that the electronegativity returns positive and negative values, while the chemical hardness always returns positive values.
