The importance of silicon and its compound in daily life

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The importance of silicon and its compound in
daily life

• 7S04 Chan Siu Yee
• 7S08 Chiu Yin Ling

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Introduction of silicon

• The 2nd most abundant element in the universe
• by mass, making up 25.7 of the crust.
• rarely occurs as the pure element in nature
• more widely appeared as a compound
• most common form is SiO2, or silica dioxide
• At room temperatures, silicon exists in two
  forms,
• Amorphous ---- brown powder while
• crystalline silicon --- metallic luster and a
  grayish color.

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Introduction of silicon

• has many industrial uses
• pure silicon is the principal component of
  most semiconductor devices, most importantly
  integrated circuits integrated circuits or
  computer-chips.
• SiO2 is mined both as sand and as vein or
  lode deposits, for use in industry.

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Importance of silicon 1. As Silicon oxides -
Construction materials

• Silicon dioxide forms giant covalent structure,
• The pure form ---- Quartz.
• The impure form ---- sand.
• both are rigid and hard materials.
• Especially sand, it as a principal constituent
  of natural stone, glass, concrete and cement.
• sand is a principal component of glass.
• important to the construction industry as
  building materials.

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Importance of silicon 1. As Silicon oxides -
Essential elements in Biology

• Silicon is important to plants.
• it contributes to form sand,
• sand it is the raw material of soil and all
  plants need soil as a place to grow.
• It is also a element for plants growth
• Silicon dioxide, indirectly affects the growth of
  plants and food resources of us.

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Importance of silicon 2. As Pure Silicon -
Essential parts of electronic devices

• Pure Silicon --- grey colour and a metallic
  lustre.
• rather strong, very brittle, and prone to
  chipping.
• used to produce ultra-pure silicon wafers used in
  the semiconductor industry,
• Hydrogenated amorphous silicon is used in the
  production of low-cost, large-area electronics in
  applications such as LCDs, and of large-area,
  low-cost thin-film solar cells.

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Importance of silicon 2. As Pure Silicon -
Making alloys

• manufacture of aluminium-silicon alloys to
  produce cast parts, mainly for the Car industry.
• important constituent of electrical steel,
• ferrosilicon or silicocalcium alloys to improve
  the performance in casting thin parts, and to
  prevent the formation of cementite at the surface
  of products.

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Importance of silicon 3. Compounds containing
silicon-oxygen and silicon-carbon bonds

• act as bonding intermediates between glass and
  organic compounds,
• form polymers with useful properties such as
  impermeable to water,
• flexible and resistance to chemical attack.
• used in waterproofing treatments, moulding
  compounds and mould-release agents, mechanical
  seals, high temperature greases and waxes,
• caulking compounds and even in
• applications as diverse as breast
• implants and explosives.

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Importance of silicon 4. Mica

• Mica has a high dielectric strength and
  excellent chemical stability,
• a favored material for manufacturing capacitors
  for radio frequency applications.
• used as an insulator in high voltage electrical
  equipment.
• used to separate electrical conductors in cables
  that are designed to have a fire-resistance
  rating in order to provide circuit integrity.
• keep the metal conductors from fusing in order
  to prevent short-circuit so that the cables
  remain operational during a fire, which can be
  important for applications such as emergency
  lighting.

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Importance of silicon 5. Silica gel

• granular, porous form of silica made
  synthetically from sodium silicate.
• most commonly encountered in everyday life as
  beads packed in a semi-permeable plastic.

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Importance of silicon 5. Silica gel - Desiccant

• By adding packets of silica gel,
• prevent moisture encourages the growth of mold
  and spoilage
• Condensation may also damage other items like
  electronics and may speed the decomposition of
  chemicals
• items can be preserved longer.

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Importance of silicon 5. Silica gel - Chemistry

• used in chromatography as a stationary phase
• the method is referred to as reverse phase
  chromatography.
• Silica gel is also applied to aluminum, glass, or
  plastic sheets for thin layer chromatography.

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Importance of silicon 5. Silica gel - Cat
litter

• by itself or in combination with more traditional
  materials, such as clays including bentonite.
• It is trackless and virtually odorless, albeit
  expensive

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Reference

• Wikipedia
• mineral.galleries.com/minerals/silicate/quartz/qua
  rtz.htm
• www.answers.com/topic/silicon-dioxide
• www.chemguide.co.uk/atoms/structures/giantcov.html
  
• www.timedomaincvd.com/CVD_Fundamentals/films/SiO2_
  properties.html

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THE END

• thankyou..