In nature, everything is made up of chemicals. They, in turn, have a complex structure that cannot be determined with the naked eye. How should the smallest particles be arranged in order for a chemical compound to take a gaseous, liquid or solid state? It depends on its crystal lattice and the bonds between atoms.
Crystal Chemistry
From the school course it is known that substances are made up of molecules, and they are made of atoms. A crystal is a solid body that, under normal conditions, takes the form of a symmetrical polyhedron. S alts can be in a crystalline state when the necessary requirements are met for their occurrence (for example, a certain temperature). The main role in such transformations is played by the structure of the studied chemical substance. Its state of aggregation and strength depend on its crystal lattice.
Types of crystal lattices
- Ionic.
- Metal.
- Molecular.
- Nuclear.
Characteristic
The essence of the first type is based on a well-known fact: positively charged ions are attracted to negatively charged ones, forming a kind of dense accumulation of them, and at the same time a corresponding crystal lattice, the atoms of which are connected by an ionic bond.
Unlike the previous one, metal is a crystal where the atoms are loosely bound to each other. Here, each of them is surrounded by many others of the same kind. Such a connection between metals can only occur if they are in a solid or liquid state, since in the gaseous state they consist of monoatomic molecules, where the atoms are not connected to each other.
Molecular is a crystal in which particles are held together only due to the forces of intermolecular interaction (for example, hydrogen bonds in water). Molecules are attracted to each other by partial charges ("+" to "-" and vice versa), resulting in a dipole-dipole interaction. If this is done with the help of particle polarization, then the electron clouds are displaced towards the center of the atomic nucleus. Such an interaction is called inductive and is characterized by the appearance of a fragile molecular crystal lattice.
Atomic crystal is a very strong body. A strong covalent polar bond prevails here. Such substances do not dissolve in water and are odorless. A well-known example is a diamond, which just has an atomic crystal lattice. Despite the fact thatdiamond, graphite and carbon black have the same formula, they are different allotropic modifications. Their difference in strength is explained by the different bonds of carbon atoms in the crystal.
