Silicon dioxideGermanium dioxideTin dioxideLead dioxide Related compoundsSilicon monoxideSilicon sulfide ThermochemistryStd molarentropy (S⦵298)42 J·mol−1·K−1Std enthalpy offormation (ΔfH⦵298)−911 kJ·mol−1Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).N verify (what is YN ?)Infobox referencesChemical compoundSilicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, most commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an electrical insulator), and as components in the food and pharmaceutical industries. SiO2 Silicon oxide Kieselerde