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Silicon: Element, Properties, Uses & Real-Life Importance

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What Are the Physical and Chemical Properties of Silicon?

Silicon is essential in chemistry and helps students understand various practical and theoretical applications related to this topic. It is a vital element for electronics, construction, and daily life, making it an important subject for students to know thoroughly.


What is Silicon in Chemistry?

A silicon refers to a chemical element with the symbol Si and atomic number 14. This concept appears in chapters related to Periodic Table, metalloids, and semiconductors, making it a foundational part of your chemistry syllabus. Silicon is a metalloid, so it has some properties of metals and some of nonmetals. 


It is the second most abundant element in the Earth's crust, mostly found in sand, rocks, and quartz as silicon dioxide (SiO₂). Silicon is extremely important in technology, especially in making electronic chips and solar cells.


Molecular Formula and Composition

The molecular formula of silicon is simply Si, because it is an element. It consists of just silicon atoms and is categorized under the group of metalloids. In nature, silicon is often combined with oxygen to form silicon dioxide (SiO₂) or with other elements in silicates.


Preparation and Synthesis Methods

Industrial production of silicon is mainly by the reduction of pure silica (SiO₂, sand or quartz) with carbon in an electric furnace:

SiO₂ (s) + 2C (s) → Si (s) + 2CO (g)

For extra pure silicon, needed in electronics, silicon is further purified by chemical reduction methods and zone refining. Lab methods may involve the reduction of silicon tetrachloride or heating silica with magnesium powder.


Physical Properties of Silicon

Property Value
Appearance Hard, grey-blue, shiny, crystalline solid
Density 2.33 g/cm³
Melting Point 1,410 °C
Boiling Point 3,265 °C
State at Room Temp Solid
Conductivity Semiconductor

Chemical Properties and Reactions

Silicon is generally unreactive at room temperature, but reacts easily at high temperatures. Its main chemical properties are:

  • Forms silicon dioxide (SiO₂) when burned in oxygen:
  • Si + O₂ → SiO₂
  • Reacts with halogens to form silicon tetrahalides (e.g., SiCl₄):
  • Si + 2Cl₂ → SiCl₄
  • Forms silicides with metals, and hydrides (silanes) with hydrogen, though silanes are unstable.
  • Does not dissolve in most acids (except hydrofluoric acid).

Frequent Related Errors

  • Confusing silicon (element) with silicone (synthetic polymer).
  • Thinking silicon is a metal (it is a metalloid).
  • Mixing up silicon dioxide (SiO₂) with pure silicon.
  • Ignoring the fact that silicon is not found free in nature.

Uses of Silicon in Real Life

  • Semiconductor chips for computers, mobile phones, and solar panels
  • Glass and ceramics manufacturing (from silica, SiO₂)
  • Steel and aluminium alloys to improve strength and lightness
  • Silicone rubbers and sealants for waterproofing
  • Cements and construction materials (as silicates)
  • Polishing powders (as silicon carbide)

Silicon is present in most sands and rocks, making it extremely important for building materials and day-to-day products. Its electrical use is unmatched thanks to its special semiconductor properties. Vedantu notes also highlight silicon’s broad role in practical chemistry.


Relation with Other Chemistry Concepts

Silicon is closely related to topics such as chemical bonding and compounds of nonmetals, helping students build a conceptual bridge between elements, compounds, and materials science. 


Learning about silicon also supports understanding periodic trends and the physical and chemical differences among metals and nonmetals.


Step-by-Step Reaction Example

1. Start with the reaction of silicon with chlorine gas at high temperature.

Si (s) + 2Cl₂ (g) → SiCl₄ (l)

2. Explain:

Silicon reacts with chlorine to produce silicon tetrachloride, a colorless liquid used in making pure silicon for electronics.

3. Conditions:

High temperature and chlorine atmosphere are required for this process.

Lab or Experimental Tips

Remember silicon by the rule of four—since it is tetravalent, it usually forms four bonds just like carbon. Vedantu educators often use models or sand samples in live sessions to help students visually connect silicon with everyday objects like glass, electronics, or beach sand.


Try This Yourself

  • Write the electronic configuration of silicon.
  • Find two differences between silicon and silicone.
  • Give three everyday uses of silicon-based materials you know.

Final Wrap-Up

We explored silicon—its definition, physical and chemical properties, reactions, everyday uses, and how it connects to your chemistry curriculum. For more in-depth explanations, experiment tips, and to clear your doubts on silicon or other elements, explore topic pages and live classes on Vedantu.


FAQs on Silicon: Element, Properties, Uses & Real-Life Importance

1. What is silicon and where is it found?

Silicon is a chemical element with the symbol Si and atomic number 14. It is a metalloid found widely in nature, mainly as silicon dioxide (sand, quartz) and silicate minerals in the Earth's crust.

2. Is silicon a metal, nonmetal, or metalloid?

Silicon is classified as a metalloid. It has properties of both metals and nonmetals, such as a shiny appearance and intermediate electrical conductivity.

3. What are the physical properties of silicon?

Silicon has the following key physical properties:

  • Colour: Grey with a metallic sheen
  • Density: About 2.33 g/cm3
  • Melting Point: 1414°C
  • Boiling Point: 3265°C
  • Crystalline structure: Diamond cubic

4. What are the main chemical properties of silicon?

Silicon is relatively unreactive at room temperature, but:

  • Reacts with oxygen to form silicon dioxide (SiO2)
  • Combines with halogens and strong bases
  • Does not react with most acids except hydrofluoric acid

5. What are the main uses of silicon?

Silicon is used in a variety of industries:

  • Making semiconductors and electronic chips
  • Manufacturing glass and ceramics
  • Producing alloys such as ferrosilicon
  • Solar panels (photovoltaic cells)
  • Construction as a component of concrete and cement

6. How is silicon extracted from nature?

Silicon is extracted mainly from silicon dioxide (SiO2) using a high-temperature reduction process:

  1. Silicon dioxide (sand) is mixed with carbon (coke)
  2. Heated in an electric furnace to about 2000°C
  3. This forms pure silicon and carbon monoxide gas

7. Who first isolated silicon, and when?

Silicon was first isolated in 1824 by Swedish chemist Jöns Jacob Berzelius using chemical reduction methods.

8. What is the difference between silicon and silicone?

Silicon is a chemical element (Si), while silicone is a synthetic polymer made from silicon, oxygen, carbon, and hydrogen. Silicon is used in electronics, while silicone is used for medical implants, seals, and cookware.

9. Why is silicon used in electronics and semiconductors?

Silicon is used in electronics because:

  • It acts as a semiconductor with adjustable conductivity
  • It is abundant and can be purified to very high levels
  • Forms a stable insulating oxide (SiO2)

10. What are the most common compounds of silicon in nature?

The most common silicon compounds in nature are:

  • Silicon dioxide (SiO2): Main ingredient in sand and quartz
  • Silicates: Found in minerals like feldspar, mica, and clay

11. Can silicon conduct electricity?

Pure silicon is a poor conductor at room temperature, but when doped with other elements, it acts as a semiconductor—the essential material for microchips and transistors.

12. Is silicon important for living organisms?

Silicon is not essential for most animals, but it is important for the structure of certain plants and diatoms. Some evidence suggests it helps strengthen connective tissues and bones.