About 90% of the minerals that make up the rocks of the Earth contain silicon. It is therefore a very common element in the crust of our planet. Almost all silicon minerals are compounds of silicon and oxygen, known as silicates. The most common silicate is quartz, the mineral form of silicon dioxide or silica. It is also the most common substance in sand. Amethyst is a type of quartz. Quartz deposits are widely found in rocks such as granite and sandstone. A valuable type of silica is opal, which is used as a gemstone. Clays used to make pottery and ceramics are also silicates.
In 1954, the first silicon transistor started what has become a global semiconductor market. Silicon is a key component of electronic chips and circuits. Wafers are very thin sheets of silicon used to make electronic circuits. It is a very versatile element, so it is also used to convert sunlight into electricity in solar panels. Artificial silica is used to create aerogel, a lightweight but tough substance that is a poor conductor of heat. It is used in a variety of applications, for example, in the fireproof suits worn by firefighters. Another silicon derivative is silicone, which can be molded into any shape. It is used in a wide range of products, from baking molds to watches and breast implants.

Summary of properties (Si)

Atomic weight[28.084, 28.086]
Discoverer (year)Berzelius, Jöns Jacob (1824)
Natural formnon-metal solid (face centered cubic)
Electron configuration[Ne] 3s2 3p2
Melting point (ºC)1410
Boiling point (ºC)2355
Abundance in earth's crust (ppm)282000
Isotope (abundance)28Si (92.223), 29Si (4.685), 30Si (3.092)
Density g/cm32.33
Van der Waals radius (pm)210
Covalent radius (pm)114
Electronegativity (Pauling)1.9
Vaporization enthalpy (kJ/mol)383.00
Enthalpy of fusion (kJ/mol)50.21
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.71
Thermal conductivity (W/cm·K) at 25ºC and 1 atm1.490
Oxidation state+4, +2, -4
Electron affinity (eV)1.39
1st Ionization potential (eV)8.1517

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