Interparticle interaction in condensed media: some elements are “more equal than others”

Some aspects of interparticle and intermolecular interaction in condensed media are discussed with special emphasis on hydrogen bonding (intermolecular interaction involving hydrogen atoms) and chemical bonds between carbon atoms. The intermediate strength of hydrogen bonding is due to the hydrogen atom having no inner shell electrons (“zero-size ion”). Hydrogen-bonded substances exhibit a large number of modifications and aggregate states at or near normal temperature and pressure conditions. What determines the diversity of carbon structures and the uniquely strong interatomic interaction they exhibit is the carbon's specific Periodic Table position (the middle of the second row). The simultaneous presence of hydrogen and carbon atoms produces a huge variety of states (including metastable ones) for organic substances to be in. The region of existence of “complex” organics lies in a rather narrow temperature-pressure range of 100–1000 K and 0–1 GPa.