Search results
Results from the WOW.Com Content Network
Silicon carbonate is a crystalline substance formed under pressure from silica and carbon dioxide.The formula of the substance is SiCO 4.To produce it silicalite is compressed with carbon dioxide at a pressure of 18 Gpa and a temperature around 740 K (467 °C; 872 °F).
The carbonate-silicate cycle is the primary control on carbon dioxide levels over long timescales. [3] It can be seen as a branch of the carbon cycle, which also includes the organic carbon cycle, in which biological processes convert carbon dioxide and water into organic matter and oxygen via photosynthesis. [5]
However, silicon has several drawbacks as a carbon alternative. Carbon is ten times more cosmically abundant than silicon, and its chemistry appears naturally more complex. [19] By 1998, astronomers had identified 84 carbon-containing molecules in the interstellar medium, but only 8 containing silicon, of which half also included carbon. [20]
Silicon dioxide is a relatively inert material (hence its widespread occurrence as a mineral). Silica is often used as inert containers for chemical reactions. At high temperatures, it is converted to silicon by reduction with carbon. Fluorine reacts with silicon dioxide to form SiF 4 and O 2 whereas the other halogen gases (Cl 2, Br 2, I 2 ...
Silicon boils at 3265 °C: this, while high, is still lower than the temperature at which its lighter congener carbon sublimes (3642 °C) and silicon similarly has a lower heat of vaporisation than carbon, consistent with the fact that the Si–Si bond is weaker than the C–C bond.
The C–Si bond is somewhat polarised towards carbon due to carbon's greater electronegativity (C 2.55 vs Si 1.90), and single bonds from Si to electronegative elements are very strong. [14] Silicon is thus susceptible to nucleophilic attack by O −, Cl −, or F −; the energy of an Si–O bond in particular is
The carbon atoms are in the same locations as the silicon and aluminum atoms of the mineral sodalite. The space group, I 4 3m, is the same as the fully expanded form of sodalite would have if sodalite had just silicon or just aluminum. [30] bct-carbon: Body-centered tetragonal carbon was proposed by theorists in 2010. [31] [32]
Carbon dioxide: 3.640 0.04267 Carbon disulfide: 11.77 0.07685 Carbon monoxide: 1.505 0.0398500 Carbon tetrachloride: ... Silicon tetrafluoride: 4.251