The importance of silicon and

its compound in daily life

7S04 Chan Siu Yee

7S08 Chiu Yin Ling

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.

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.

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.

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.

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

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.

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.

Importance of silicon: 2. As Pure Silicon - Making alloys

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.

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.

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.

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.

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.

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

Reference: Wikipedia mineral.galleries.com/minerals/silicate/quartz/

quartz.htm

www.answers.com/topic/silicon-dioxide www.chemguide.co.uk/atoms/structures/giant

cov.html www.timedomaincvd.com/CVD_Fundamental

s/films/SiO2_properties.html

THE END*

thankyou..