Silicon

Silicon is second most abundant element found in earth’s crust. It constitutes about 27.7% of the total mass of earth’s crust. Silicon is represented by the symbol ‘Si’. Its atomic number is 14 and is found in group 14 and the third period of the periodic table. It is metalloid in nature and forms the backbone of the semiconductor industry. Due to its low reactivity, it is also used in body implants.

In this article, we will learn in detail about silicon, its symbol, properties, and applications.

What is Silicon?

Silicon is a chemical element with the symbol Si and an atomic number of 14. It is hard, brittle, and crystalline, with a metallic blue-grey lustre. It is a member of the carbon group in the periodic table. It belongs to Group 14 in the periodic table. It is a p-block element. It is neither a metal nor a non-metal, but a metalloid. One of the characteristics of this material is its semiconductor features. It is a fundamental element in the production of electronic devices.

Silicon Element Symbol

The symbol of Silicon element is shown below:

Silicon Element Data

The detailed data of silicon element is tabulated below:

Silicon Element
Symbol	Si
Atomic Number	14
Atomic Mass	28.0855 amu
Electron Configuration	[Ne] 3s2 3p2
Density	2.3296 g/cm3
Melting Point	1,414 °C (2,577 °F)
Boiling Point	3,265 °C (5,909 °F)
Phase at Room Temperature	Solid
Color	Shiny, grayish-black
Crystal Structure	Diamond cubic
Common Isotopes	28Si, 29Si, 30Si (with 28Si being the most abundant)
Electronegativity	1.90 (Pauling scale)
Metallic Properties	Metalloid

Properties Of Silicon

Silicon is an important element in chemistry as well as in electronics. It is abundantly found in earth crust and possess unique properties. The properties of silicon can be studied in two categories

• Physical Properties of Silicon
• Chemical Properties of Silicon

Physical Properties of Silicon

The physical properties of silicon are mentioned below:

State at Room Temperature: At standard room temperature silicon has a solid structure. It is formed from a hexagonal structure resembling crystals, resulting in an appealing metallic sheen.

Density: A silicon density tucked in approximately 2.3296 grams per cubic centimeter. Low density leads to the mouldings significance because it is lightweight.

Melting Point: Silicon has very high melting point of 1,414℃(2,577 ℉ )

Boiling Point: The melting point of silica is likewise very high approximating 2180℃(3915℉ ).

Crystal Structure: Silicon has cubic diamond crystal lattices that offer a degree of hardness and a strength to silicon.

Electrical Conductivity: Silicon is a semiconductor. It has medium electrical conductivity. This makes it suitable for usage in electronics sector.

Malleability and Ductility: Silicon is neither malleable or ductile. Rather it is hard and brittle

Chemical Properties of Silicon

The chemical properties of silicon are mentioned below:

Reactivity: Silicon is chemically harmless under normal circumstances. It does not readily react with the majority of acids or bases.

Oxidation: When the silicon meets oxygen, it forms an SiO₂ (Silicon dioxide) layer on its surface. This oxide layer act in passivation role, hence protecting underlying layer from oxidation.

Combustibility: Silicon does not react easily in standard atmospheric conditions; this is perfect for its use in high-temperature applications.

Hydride Formation: Silicon reacts with hydrogen creating hydrides, such as silane (SiH₄).

Halogen Reactivity: Reaction of silicon with halogens (fluorine, chlorine, bromine, iodine) gives silicon tetrahalides, e.g. silicon tetrafluoride (SiF₄) and silicon tetrachloride (SiCl₄).

Alloy Formation: Silicon forms compounds with metals that are lighter than it, such as ferrosilicon(iron and silicon alloy).

Amphoteric Nature: Silicon has a characteristic of being amphoteric which implies that it can react as an acid and as a base. It may form salts with either acid or base.

Reaction with Alkali Metals: Si interacts with alkali metals (such as sodium and potassium) to produce silicides.

Silicon Compounds

Silicon can react with other elements forming large number of stable chemical compounds. Some of such silicon derived compounds along with their chemical formulas are mentioned below:

Silicon Compounds	Chemical Formulas
Silicon Dioxide	SiO2
Silicon Carbide	SiC
Silicon Tetrachloride	SiCl4
Silicon Tetrafluoride	SiF4
Silane	SiH4
Disilane	Si2H6
Silicon Monoxide	SiO
Silicon Nitride	Si3N4
Silicon Monosulfide	SiS
Silicon Phosphide	Si3P4
Trisilicon Tetranitride	Si3N4
Sodium Silicate	Na2SiO3
Silicon Tetrahydride	SiH4
Hexachlorodisilane	Si2Cl6

Polymers of Silicon

Silicon has catenation property although not as long as carbon. This property of silicon qualifies it to form long chain polymeric compounds. These polymers based on silicon are called silicones or polysiloxane.

Polysiloxanes have a general structure where silicon atoms are alternately bonded to oxygen atoms and organic groups, typically methyl (-CH3) groups. An example is Polydimethylsiloxane (PDMS), which is composed of repeating units of [-Si(CH3)2O-].

Silicones exhibit a variety of useful properties such as flexibility, heat resistance, water repellency, and biocompatibility. They find applications in various industries including automotive, electronics, medical devices, cosmetics, and construction

Some other classes of compounds formed by silicon are:

• Silanes: They include family of silicon hydrides
• Silicide: They have a structure similar to carbide and boride
• Silica: It is silicon dioxide. It is usually found in sandstone.

Uses Of Silicon

Silicon due to its unique metalloid properties has got application in various sectors. The applications of silicon are mentioned below:

Semiconductor Industry: Silicon is a key element in the manufacturing of semiconductors such as chipsets, transistors, integrated circuits and microprocessors. The semiconducting feature of silicon makes it to be the switch that either controls or amplifies the electrical signals in the electronic devices.

Solar Energy: Silicon is extensively used in the fabrication of photovoltaic cells used in solar panels. By using the photovoltaic effect solar silicon cells transform the sunlight into electricity, which makes silicon an important participant in the energy transition.

Metallurgical Industry: Silicon is employed in the process of alloy production; an example of alloys include ferro and aluminum silicon alloys. These mixed alloys are in use in metallurgical industry for deoxidation and enhancing the properties of the metals.

Construction Materials: Silicone is made from silicates that occur naturally and also from the melting of sand. It is used in the production of silicones, a class of synthetic materials that are used as sealants and adhesives in construction and waterproofing. Silicones provide reliable durability and specific resistance to high temperatures.

High-Temperature Applications: The semiconductor silicon carbide, an alloy of silicon and carbon, is known for its high resistance to wear and good thermal conductivity. It serves the production of abrasives, cutting tools, and as a refractory material at high temperatures.

Glass and Ceramics: Silicon dioxide (silica) is a essential for the making of glass and ceramics. Silicon participates in their formation, which causes these materials to be stronger, with higher heat resistance, and are transparent.

Electronics and Computers: The semiconductor field does not exhaust the application scope of silicon: it is also involved in different types of electronic components, like diodes and transistors. It is crucial electrical property of such material that makes it a base in the electronics and computer fields.

Medical Applications: Silicone, which in turn is derived from silicon is used in medical devices like implants, catheters or tubing among others, because of their biocompatibility and inert properties.

Facts About Silicon

Abundance: Silicon is second most abundant mineral found in earth crust. About 27.7% of Earth’s crust by mass consist of silicon

Semiconductor Properties: Silicon has excellent semiconductor properties hence, used in transistors, integrated circuits, and microprocessors.

Solar Energy: Silicon is one of the prime ingredients that are used in solar cell manufacturing, where the cells absorb light energy from the sun and turn it into electricity.

Glass Formation: The glass that you have probably been using contains silicon dioxide which is technically called as silica.

Crystal Structure: Silicon posses cubic diamond crystal structure.

Brittle Nature: Silicon is hard and brittle in nature

Catenation Property: Silicon posses catenation property i.e. silicon atoms can join each other forming chain. However these chains are not as long and stable as carbon chain.

Silicon Frequently Asked Questions

What is silicon?

Silicon is a chemical element, the chemical symbol for which is Si with atomic number 14. It is a metalloid that has characteristic features of both metal and non-metal elements.

What percent of earth’s crust is silicon?

About 27.7 % of Earth’s crust made up of silicon. It is the second most common element in the Earth’s crust, existing mostly in the form of silicate minerals, such as quartz.

Is silicon metal or non-metal?

Silicon is neither a metal nor a non-metal, but it is a metalloid

Why is silicon used in electronics industry?

Silicon is a semiconductor which means it can carry small amount of current and supply to low powered devices. This makes silicon a prominent element in the field of electronics

Is silicon reactive?

Silicon is generally unreactive at ordinary temperature. However it can react at elevated temperature

What is polymer of silicon called?

Polymer of silicon is called silcones or polysiloxanes