Silicon is a chemical element with the symbol Si and atomic number 14. It is the eighth most abundant in the Universe and the second most abundant element on Earth.

It is a tetravalent metalloid and semiconductor. It is a member of group 14 on the periodic table and its oxidation state is -2.

Several important compounds and materials of silicon are obtained from silicate minerals, including glass (silicon dioxide) in sand, and ceramics and abrasives (silicon carbide) made from clay. These substances are used in a wide variety of applications.

Silicon-based polymers and synthetic compounds, such as silicones, are also significant silicon-containing materials. They have nonstick and rubber-like properties and are often used in cookware, medicine (implants), sealants, adhesives, lubricants, and for insulation.

Silver is a tetravalent metalloid that belongs to group 12. It is the sixth most abundant in the Universe and the fourth most abundant element on Earth.

It occurs in nature in a range of forms, most importantly as a component of natural silicates in soil, rocks and water. These substances are essential for plant growth, as well as for the formation of many other materials.

The most abundant naturally occurring form of silicon is the mineral silicon dioxide, which can be found in sand and other clays. It is also found in crystalline forms, such as quartz. It is also the main component of the substance in high-precision watches and clocks, and is a major element for the production of silicon wafers used in computer chips.