THE RELATIONSHIP BETWEEN THE CHEMICAL STRUCTURE OF IА–VIIА SUBGROUPS METAL HYDRIDES (NON-METALS) OF D.I. MENDELEEV’S PERIODIC TABLE AND THEIR FIRE AND EXPLOSIVE PROPERTIES

An analysis of the relationship between the chemical structure of IA–VIIA subgroups metal hydrides (nonmetals) of D.I. Mendeleev’s periodic table and their fire and explosive properties has been performed. There is considered the difference between the following types of hydrides: ionic, covalent, metallic and complex, depending on the type of bond between metal (nonmetal) atoms and hydrogen. It is indicated that when the electronegativity of the elements is very different, the bond between the atoms is ionic. If there is no difference in the electronegativity of the elements, the bond will be nonpolar, and if there is a difference, it will be polar. Ionic hydrides are formed by the interaction of hydrogen with alkaline and alkaline earth metals of IA, IIA subgroups at elevated temperatures and pressures. Attention is drawn to the nature of the covalent bond, which is characteristic of IIIA–VIIA subgroups hydrides of the periodic table. It is more complex than the ionic bond. The fire and explosion hazard of hydrides is analyzed, which is determined by the bond between the atoms. The higher the chemical activity (reactivity) of hydrides, the greater the electronegativity of the elements (metal, nonmetal – hydrogen) and the higher the polarity of the atoms between the metal (nonmetal) and hydrogen in the hydride molecule, and, consequently, the lower the stability of the compound. The presented data on the relationship between the chemical structure of metal hydrides (nonmetals) and their fire and explosion hazard allow to predict their flammability and explosiveness level based on the known information about the nature of the bond between an element and hydrogen (ionic, covalent, metallic, or complex).