Why SiO2 can be considered as an insulator?
464864
In gap between the valence band and the conduction band is very high. Conductors have overlapping bands. Semiconductors have small gaps (e.g., Si=1.1eV). Insulators have high gaps (SiO2 about 8 or 9eV).
180275
Silica is simply SiO2, so silica oxide really is no diferent than just silica.  Silica is very common in the world in the form of sand, and therefore doesn't usually need to be synthesized, although it is ustually ground and sieved to acquire only one particle size for abrasives.
497397
Let's say you're really hungry. If I lock a cupcake in a metal box and give you the box can you get to the cupcake without a key?\n\nNope.\n\nMetal oxides work the same way. By coating a metal in a desirable oxide (ie. as in aluminium anodizing) you're sealing the unprotected metal from more harmful forms of oxidization. If oxygen can't react with the surface of the metal because its already reacted with something else to form an oxide. Because of that you just prevented further oxidization BY oxidizing. There's no key, no reaction, to further degrade the metal underneith.\n\nThere are other things besides oxide coatings that can keep good ole' redox at bay. One is called a sacrificial anode and its commonly used on exposed metal on things like oil rigs.
650119
Less dense materials are better insulators. The denser the material, the closer its atoms are together. That means the transfer of energy of one atom to the next is more effective. Thus, gases insulate better than liquids, which in turn insulate better than solids.\n\nAn interesting fact is that poor conductors of electricity are also poor heat conductors. Wood is a much better insulator than copper. The reason is that metals that conduct electricity allow free electrons to roam through the material. This enhances the transfer of energy from one area to another in the metal. Without this ability, the material--like wood..AND IN YOUR CASE RUBBER--does not conduct heat well.
53419
Answer 1:\n"Glasses" are amorphous solids, that is, they don't have a regular shape.\nEssentially the opposite of crystalline solids which have a defined shape.\nWhen you break a crystalline solid, it will give flat, well defined faces.\nCrystals melt or decompose at definite temps and the change from s to l\nis usually abrupt.  Glass (say window glass) will shatter into irregular\nfaces and curves.  There are many different kinds of glass and none really\nhave a melting point.  All pretty much have silicon dioxide as a principle\ningredient then something else added:  Here are some numbers...keep in mind\nthese are all SOFTENING  points and NOT melting points:\nsilica glass: 1580 Celsius   soda-lime glass: 695 C\nborosilicate glass: 820 C    aluminosilicate glass: 915 C\nleaded glass: 630 C\nWhat I'm trying to say is:  glass isn't a liquid.  It's a solid with so\nmany 'defects' that the order inherent in a crystal is absent.  When I\nsay defects, I'm talking at the molecular level, not physical scratches,\nand so on. You may want to recheck that 100 K number you presented.\nThat's 173 degrees Celsius below zero (-280 F)!\nAm I going to get some arguments about my stance?  I'll find out more\nfrom our resident glassblower here at the university.\n-Joe Schultz\n\nAnswer 2:\nI very much agree with J. Schultz's response...  Here are a couple\nof other observations:\nGlass is formed by melting silicon dioxide (SiO2) which has a\nmelting point of 1710 deg. C..  In its crystalline form, SiO2\nhas a very ordered structure with each Si atom bonded to 4 O atoms\nand each O atom attached to two Si atoms.  If the SiO2 is quickly\ncooled after being melted, the SiO2 "molecules" do not have a chance\nto get completely lined up in their solid crystalline form and thus\nan amorphous solid (glass) is formed.\nOften we like to categorize substances as gas, solid, or liquid..\nobviously, glass is somewhere between a solid and a liquid --\nsome scientists refer to it as a pseudo-solid\n-Dr. Brown
1034076
Insulating materials such as rubber, plastic or those extremely expensive materials made from Silica.
54282
I think that the question must be -What is an electrical insulator?-, because it's material that does not have much free electrons, so the energy to make them jump out of the atom is so great that in normal situations (unless the voltage is really big, like a thunder) the electrons won't flow through it.
922061
An insulator is a material containing no electrical charges. When a voltage is sent across an insulator, no charges flow, so there is no electrical voltage\n\nGenerally,all non metals materials are good insulators.Such as plastic,glass,rubber(frying pot handle)
114277
Because in SiO2, polymerization occurs whereas in CO2 , polymerization is not possible. Polymerization of large no. of SiO2 makes it solid.
512575
We review theoretical interpretations of Schottky barriers and Fermi-level pinning, which result when metals and other chemical species are deposited on semiconductor surfaces. Experiments indicate that these two phenomena are closely connected, so a theory of Schottky barriers must also explain Fermi-level pinning for submonolayer coverages of both metallic and nonmetallic species. Proposed mechanisms include the following: (a) Intrinsic surface states. For GaAs and several other materials, there are no intrinsic surface states within the band gap; GaP, e.g., does have surface states in the gap, but they are not at the correct energy to explain Schottky barrier formation. (b)Metal-induced gap states. These states, which require a thick metal overlayer, cannot explain Fermi-level pinning at submonolayer metallic coverages. They also cannot explain why a single semiconductor (n-type InP) exhibits two distinct Schottky barrier heights. Furthermore, they cannot explain why the Schottky barrier persists when there is an oxide layer between semiconductor and metal. Metal-induced states can in principle give rise to Schottky barriers at defect-free interfaces, but they fail to explain much of the existing experimental data for III–V semiconductors and Si. (c) The classic Schottky model. This model is not in agreement with experiment for III–V and Group IV semiconductors, but does appear to account for the measurements involving nonreactive metals on GaSe–a layered material expected to be relatively free of defects. (d) The Spicer defect model. This phenomenological model, now supported by microscopic theoretical studies, appears to account for many of the observations regarding Schottky barrier and Fermi-level pinning. We review our theoretical investigations within the framework of the defect model, which provide a satisfactory explanation of the principal observations for both III–V and Group IV semiconductors. We conclude that the levels responsible for Schottky barriers and Fermi-level pinning arise from two sources: (1) bulk-derived deep levels (e.g., the deep donor level for the antisite defect AsGa, which persists when this defect is present at the surface, but which is shifted in energy), and (2) dangling-bond deep levels (which are also shifted in energy according to the environment of the dangling bond). Most of the observed Schottky barriers—for both III–V and Group IV semiconductors—are attributed to dangling bon
889370
carbon has no free electrons available\nso it cannot conduct electricitys\nin case of germanium and si they have d orbits in the outer shell and they have greater mobility
634755
It already exist...it is called ceramic. Glass is also silicon based.\nThey've been using them for years on old telegraph and telephone poles. The are still used in the electrical industry.\n\nIf you are referring to the soft silicon that fake boobs and adhesives are made from the answer in durability. It is not structurally solid enough to be used reliably.
1088099
insulators ; conduction
982255
no, because even silicon which is a semi-conductor and used in microchips when it is purified to 99.999% purity, is only a semi-conductor. silicon occurs in crystal form as silicon dioxide.\nin its different forms it can either be a semi-conductor or an insulator.\nsand isn't going to conduct electricity just because an element appears in it in the form of a compund bonded molecule. afterall, H20 conducts electicity, does sugar that also contains water do so in crystalline form? no!\n\nwet sand will conduct electicity, but that is actually the water doing the conducting of the electrical current.\ndry sand is an insulator just like any crystal.\n\nnow if you happen to walk into an environment that has sand made of 99.999% Si and a thunderstorm blows up, the lightning should scare you a little bit.\n\ncement is made of sand, do you see it conducting electricity?\n\nif you take dionized water, which doesn't conduct electicity well, and dump a little sand into it, it may add enough electolytes to improve he electical conductivity of the water, but dry sand on its own does not!
794794
Silicon Dioxide (S02)
831022
Chemically pure water is an electrical insulator.\n\nEven the least impurity, even the least amount of any dissolved ion, will convert it into a conductor.  Even dissolved CO2 will provide the ionic activity to make water conductive
226343
Syrofoam is primarily air space, and is thus an extremely poor conductor, but a good insulator.  Im not sure why you thought it was a conductor.