Periodic Table of Elements




Silicon was first identified by the French chemist Antoine Lavoisier in 1787. He proposed that a new chemical element could be found in quartz. Silicon was re-discovered by Jns Jacob Berzelius, a Swedish chemist, in 1824 by heating chips of potassium in a silica container and then carefully washing away the residual by-products.

Name: Silicon
Symbol: Si
Atomic number: 14
Atomic weight: 28.085
State: solid
Group, period, block: 14, 3, p
Color: crystalline, reflective with bluish-tinged faces
Classification: metalloid
Electron configuration: 3s23s2 3p2

Physical properties

Density: 2.3290 g.m-3
Melting point: 1687 K, 1410 C, 2577 F
Boiling point: 3538 K, 3265 C, 5909 F

Atomic properties

Oxidation states: 2, 1[1]
Electronegativity: 1.90 (Pauling scale)
Ionization energies: 1st: 786.5 kJmol-1
Covalent radius: 111 pm
Van der Waals radius: 210 pm
  • Si
  • Electron Configuration


There are three naturally occurring isotopes of silicon exist, 28Si, 29Si, and 30Si.