Transcript The importance of silicon and its compound in daily life

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.




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.
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.
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.
Importance of silicon:
3. Compounds containing silicon-oxygen and siliconcarbon 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 shortcircuit 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..