Crystal.

a solid with a certain geometric polydesome shape, called crystals, which are arranged in space by atoms, molecules, ions and other structural particles in space. The crystal therefore has a certain shape, because the structural particles (atoms, molecules, ions) within the crystal are closely related by a certain force of force, and to determine the location in space for a defined arrangement. Depending on the type of structural particles, the properties of their forces are different, so the crystals are divided into four large categories. The first category is ion crystals (e.g.
NaCl, CsCl), where the structural particles are metal positive and halogen negative ions, which are combined by electrostitive gravity. The second category is atomic crystals (e.g. diamond, SiO 2 ), the structural particles of the crystals are atoms, which are combined by co-priced bonds. The third category is metal crystals (e.g. tungsten, copper, etc.), metal atoms bonded by metal bonds. The fourth category is molecular crystals (e.g. dry ice, benzene crystals), structural particles are molecules, by molecular force binding. Crystals have different properties than a fixed-shaped solid. The first is that crystals have uniformity and antho-heterogeneity. Antho-heterogeneous means that there are different properties of light, electricity, heat, and force in different directions, and the degree of antho-heterogeneity of the various parts of the crystal is completely uniform. The second is that crystals have symmetry and
X-rays to the crystal.
X-ray
the wavelength of the crystal and the atomic spacing in the crystal belong to the same order of magnitude. Diffraction occurs when X-rays are used to irradiated crystals. The third is that crystals have their own paradigms, that is, they spontaneously grow complete geometric polymorphosic shapes consisting of crystal surfaces, prisms and vertigos. The fourth is that the crystal has a fixed melting point. Crystals
to
at a certain temperature and begin to melt. At this point, all the energy provided by the outside world is used to melt the crystals, and the temperature does not rise. The temperature did not rise until the crystals were completely melted. The natural plane of the crystal is called the crystal surface, and the intersection of the two crystal surfaces is called the crystal prism. Crystals may produce defects or distortions when formed, but the angle between crystal surfaces is always constant. The dot matrix theory used to study crystal structure can be applied approximately. The periodicity of crystal structure consists of two aspects: first, the size of the repeating cycle and the law of change, and second, the specific content of periodic changes (i.e., the type, number and connection of atoms, ions or molecules, etc.). The former can be represented by dot matrix, while the latter is represented by structural substruct. Therefore, the crystal structure can be summarized as a crystal structure , dot matrix structure base. A structural binary can be abstracted into a point in geometry, that is, a d'equid? These dstrones are arranged periodically in space in a certain way to form a spatial dot matrix.