The content of silicon in the earth's crust ranks second (second only to oxygen). There is no free silicon in nature. It is widely present in various minerals in the earth's crust in the form of chemical compounds (such as silicon dioxide and silicate). And among the rocks.

(1) Silicon element has two forms: crystalline and amorphous. Silicon crystals have a regular tetrahedral spatial network structure, similar to diamond, usually grayish black, with metallic luster, high hardness, high melting point, and conductivity between Between the conductor and the insulator, it is a good semiconductor material.

(2) Silicon is chemically inactive at room temperature. ① It can react with O2, Cl2, C and some oxides under heating or high temperature; ② It can react with F2, HF and strong alkali solutions at room temperature.

(3) The use of silicon. High-purity silicon is a good semiconductor material and is often used in the manufacture of integrated circuits, transistors, and solar cells.