Silicon

Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid and semiconductor.

What the numbers say

At standard temperature and pressure Silicon is a solid, sitting in period 3, group 14 of the p-block.

Its melting point of 1687 K (1414 °C) is the 34th highest of the 110 elements with a measured value — mid-range among the elements.

At 2.33 g/cm³ it is the 74th densest of 96 elements with a quoted density.

Pauling electronegativity is 1.9. Paired with oxygen (3.44) that is a difference of 1.54, which puts the bond polar covalent — oxides here tend to be semiconducting or refractory rather than salt-like.

In the solid state it takes a tetrahedral packing structure.

It is reported in 8 oxidation states (-4, -3, -2, -1, 1, 2, 3, 4), which sets how many distinct compounds and phases it can form.

First identified in 1824.

Where silicon shows up in engineering materials

3 entries in the materials library name it directly:

• Silicon carbide (SSiC) — Non-oxide ceramic
• Silicon nitride Si₃N₄ — Non-oxide ceramic
• Monocrystalline silicon — Elemental semiconductor

Check it against computed structures

The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Si — with DFT formation energy, hull stability and band gap where the provider publishes them.