What allotropy



In science, there is such a thing as allotropy - ie the ability of a chemical element to form a few simple substances, which differ only in the crystal lattice (especially chemical bonds form and atoms of the material order of coupling between them).Allotropy not dependent on the aggregate state of the substance, it can have both solids and liquid, or plasma.An example of this, from the seemingly complex phenomenon known to every schoolboy: solid diamond and graphite fragile.Both are connected by a chemical bond between the carbon atoms (C), only the graphite crystal lattice similar to the flat scales, but the structure of the diamond is a branched compound.That is why the same chemical element, which is in the same state of aggregation, has such different properties.

Why confusion



If we consider just the water - it is a complex matter.In other words, its molecules consist of several atoms, and the term "allotropic modifications" applies only to simple substances.Allotrope is often confused with the phenomenon of "polymorphism" chemicals, which occurs only in those substances, which are in the solid state.Confusion occurred because he and the other term is applicable to both chemicals that are both simple and firm in one and the same time.An example is the iron - is stored at room temperature in the solid state and at the same time is simple substance, i.e. consists only of atoms of chemical elements that are not associated in the molecule.

Conclusion



term "allotropy" can be applied only to simple substances, and water is a complex matter.Therefore, it being in a solid state (as ice) has just polymorph.The latest data revealed fourteen different kinds of ice structure, but perhaps soon will open more than one.Most of these modifications can only exist in the space environment, at low temperatures (below 110 degrees Celsius) or at high pressure (up to 700 atmospheres).This suggests that the question of "how much water has allotropic states" can be answered with a single word - not at all.