Page 20 - Curriculum Visions Dynamic Book

Sg see Seaborgium Silicon (Si)
Element 14. Silicon is a metalloid (between a metal and a non-metal) in group 4 (the carbon group) in the Periodic Table. Silicon has a structure and many properties similar to the diamond form of carbon.
Silicon does not occur uncombined, but always with oxygen as silicates and other minerals. Quartz (SiO2, silicon dioxide, or silica) is a compound of silicon and oxygen. Sand and clay are also compounds dominated by silica.
Pure silicon is a hard, dark grey solid. Silicon is unreactive with water or acids. It is the main component
in glass.
The atomic structure of silicon has made it a very important semi-conductor. It is the basis
of silicon chips in computers.
Discovery
Discovered by Jöns Jacob Berzelius in Sweden in 1824.
Technology
One of the main uses of the mineral is as
a base for silicon chips in the electronics industry. It is doped with boron, gallium, phosphorus or arsenic to make a wide range of solid-state devices.
Silica as silicone is a waterproof inert sealer. Silica as sand is used in most buildings.When heated and softened, it can be formed into glass.
 Glass is made from silicates, which in the form of sand are abundant and widespread.
Key facts...
Name: silicon
Symbol: Si
Atomic number: 14
Atomic weight: 28.09
Position in Periodic Table: group 4 (14)
(carbon group); period 3
State at room temperature: solid
Colour: dark grey with a bluish tinge Density of solid: 2.33 g/cc
Melting point: 1,410°C
Boiling point: 2,355°C
Origin of name: from the Latin word silicis,
meaning flint
Shell pattern of electrons: 2–8–4
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