Why SiO2 have two kinds of crystal and non crystal? How do I get it?
Natural silica is divided into crystalline and amorphous two categories, crystalline silica mainly exists in quartz. Pure quartz is a colorless crystal with large transparent prisms and crystals of quartz. Silicon dioxide is an atomic crystal of the tetrahedral structure of silicon atoms with four oxygen atoms. The whole crystal can also be regarded as a huge molecule. SiO2 is the simplest and does not represent a single molecule. Density 2.32g/cm3, melting point 1723 + 5 DEG C, boiling point 2230 DEG C. Amorphous silica is a white solid or powder
SiO2 uses two forms of existence in nature: one is crystalline, such as crystals, diamonds, etc., similar to precious stones, having regular shapes, fixed boiling points, and all the properties of crystals. One is non crystalline, such as silica glass, similar to glass, irregularly shaped, with no fixed boiling point, and conforms to amorphous properties.
The crystal is SiO2 which are each silicon atom and four oxygen atoms around with the formation of four covalent bonds, each oxygen atom and two silicon atoms surrounding the formation of covalent bonds, the spread of it, forming a strong network structure, it is the crystal of SiO2. Non covalent crystal silica in silicon and oxygen atoms with very irregular, with a silicon atom and two oxygen atoms form two covalently combine into one molecule, are also part of the mesh structure, hardness, density and melting point is lower than the non crystal crystal too many.
