Silicon (Si)

From Wikipedia, the free encyclopediaSilicon is a chemical element with symbol Si and atomic number 14. It is a tetravalent metalloid, more reactive than germanium, the metalloid directly below it in the table. Controversy about silicon's character dates to its discovery.

Silicon in the periodic table

SymbolSi
Atomic number14
Group14
Period3
Blockp
Element categoryMetalloid

Physical properties

Phase at STPSolid
Density2.329 g/cm3
Atomic weight28.085 u
Melting point1687 K
1413.85 °C
2576.93 °F
Boiling point3538 K
3264.85 °C
5908.73 °F

Atomära egenskaper

Electronegativity (Pauling Scale)1.9
Electron affinity134.068 kJ/mol
Ionization energies
1786.5 kJ/mol
2 1577.1 kJ/mol
3 3231.6 kJ/mol
4 4355.5 kJ/mol
5 16091 kJ/mol
6 19805 kJ/mol
7 23780 kJ/mol
8 29287 kJ/mol
9 33878 kJ/mol
10 38726 kJ/mol
11 45962 kJ/mol
12 50502 kJ/mol
13 235196 kJ/mol
14 257923 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p2
Electrons per shell2, 8, 4

History

Discovered1823
Discovered byJöns Jacob Berzelius
Named byThomas Thomson (chemist)