| Physical Description |
Silicon powder, amorphous appears as a dark brown powder. Insoluble in water and denser than water. Burns readily when exposed to heat or flames, and may be difficult to extinguish. Water may not be effective in extinguishing flames. Used to make computer microchips. |
| Color/Form |
Black to gray, lustrous, needle-like crystals or octahedral platelets (cubic system); amorphous form is dark brown powder |
| Boiling Point |
4271 °F at 760 mmHg (NIOSH, 2023) |
| Melting Point |
2570 °F (NIOSH, 2023) |
| Solubility |
Insoluble (NIOSH, 2023) |
| Density |
2.33 at 77 °F (NIOSH, 2023) - Denser than water; will sink |
| Vapor Pressure |
0 mmHg (approx) (NIOSH, 2023) |
| Viscosity |
Dynamic viscosity = 0.88 cP at MP and 0.7 cP at 1500 °C; kinematic viscosity (calculated) = 0.347 cSt at MP and 0.28 cSt at 1500 °C /Liquid silicon/ |
| Heat of Combustion |
-9.0550x10+8 J/kmol |
| Heat of Vaporization |
16 kJ/g |
| Surface Tension |
736 dyn/cm at MP; 720 dyn/cm at 1500 °C /Liquid silicon/ |
| Other Experimental Properties |
Atomic number: 14; valence: 4, 2; poor conductor of electricity ... lattice constant (25 °C): 5.41987X10-8 cm; compressibility (vol/vol 0) at 25x10+3 kg/sq cm: 0.978; at 100x10+3 kg/sq cm: 0.940; dielectric constant: 13; covalent bond ionization energy at 0 K = 1.2 electron volt; band gap: 1.106 electron volt; impurity atom ionization energy: approx 0.04 electron volt; intrinsic resistivity at 300 K = 0.23 megaohm; average heat capacity (16-100 °C): 0.1774 cal/g/deg C |
| Chemical Classes |
Mineral Dusts -> Other Mineral Dusts |
