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Metasilicic Acid
Metasilicic acid is a hypothetical chemical compound with formula .M. F. Bechtold (1955): "Polymerization and Properties of Dilute Aqueous Silicic Acid from Cation Exchange" ''Journal of Physical Chemistry'', volume 59, issue 6, pages 532–541. The free acid slowly polymerises in aqueous solution even at low concentrations and cannot be isolated under normal conditions. Compounds including the conjugate base are known as metasilicates and occur widely in nature as inosilicate Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dio ...s. See also * Orthosilicic acid References {{reflist Oceanography Aquatic ecology Hypothetical chemical compounds Silicon compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasilicate
320 px, Idealized structure of sodium metasilicate. Metasilicates are silicates containing ions of empirical formula . Common stoichiometries include MSiO3 and MIISiO3. Metasilicates can be cyclic, usually the hexamer or chains . Common compounds containing metasilicate anion are: * Inosilicates * Metasilicic acid (hydrogen metasilicate) * Sodium metasilicate * Calcium metasilicate References Silicon oxyanions {{Inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken or new bonds formed or both. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasilicate
320 px, Idealized structure of sodium metasilicate. Metasilicates are silicates containing ions of empirical formula . Common stoichiometries include MSiO3 and MIISiO3. Metasilicates can be cyclic, usually the hexamer or chains . Common compounds containing metasilicate anion are: * Inosilicates * Metasilicic acid (hydrogen metasilicate) * Sodium metasilicate * Calcium metasilicate References Silicon oxyanions {{Inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inosilicate
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dioxide, ) are usually considered to be Silicate mineral#Tectosilicates, tectosilicates, and they are classified as such in the Dana system (75.1). However, the Nickel-Strunz system classifies them as oxide minerals (4.DA). Silica is found in nature as the mineral quartz, and its polymorphism (materials science), polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this carbonate–silicate cycle, geologic cycle. For example, a type of plankton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthosilicic Acid
Orthosilicic acid () is an inorganic compound with the formula . Although rarely observed, it is the key compound of silica and silicates and the precursor to other silicic acids . Silicic acids play important roles in biomineralization and technology.N. N. Greenwood, A. Earnshaw, ''Chemistry of the Elements'', 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997. It is the parent acid of the orthosilicate anion . Isolation Typically orthosilicic acid is assumed to be a product of the hydrolysis of its esters, , where R stands for organyl group, as is practiced in sol-gel syntheses. These conditions are however too vigorous to allow isolation of the parent acid. Orthosilicic acid can be produced by Pd- catalyzed hydrogenolysis of tetrabenzoxysilicon: : The acid was crystallized from a solution of dimethylacetamide and tetrabutylammonium chloride. As established by X-ray crystallography, the chloride anions interact with the acid via hydrogen bonds. Otherwise, the structure con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanography
Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of topics, including ocean currents, waves, and geophysical fluid dynamics; fluxes of various chemical substances and physical properties within the ocean and across its boundaries; ecosystem dynamics; and plate tectonics and seabed geology. Oceanographers draw upon a wide range of disciplines to deepen their understanding of the world’s oceans, incorporating insights from astronomy, biology, chemistry, geography, geology, hydrology, meteorology and physics. History Early history Humans first acquired knowledge of the waves and currents of the seas and oceans in pre-historic times. Observations on tides were recorded by Aristotle and Strabo in 384–322 BC. Early exploration of the oceans was primarily for cartography and mainly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Ecology
An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environment. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. Freshwater ecosystems may be lentic (slow moving water, including pools, ponds, and lakes); lotic (faster moving water, for example streams and rivers); and wetlands (areas where the soil is saturated or inundated for at least part of the time). Types Marine ecosystems Marine coastal ecosystem Marine surface ecosystem Freshwater ecosystems Lentic ecosystem (lakes) Lotic ecosystem (rivers) Wetlands Functions Aquatic ecosystems perform many important environmental functions. For example, they recycle nutrients, purify water, attenuate floods, recharge ground water and provide habitats for wildlife. The biota of an aqua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothetical Chemical Compounds
A hypothesis (: hypotheses) is a proposed explanation for a phenomenon. A scientific hypothesis must be based on observations and make a testable and reproducible prediction about reality, in a process beginning with an educated guess or thought. If a hypothesis is repeatedly independently demonstrated by experiment to be true, it becomes a scientific theory. In colloquial usage, the words "hypothesis" and "theory" are often used interchangeably, but this is incorrect in the context of science. A working hypothesis is a provisionally-accepted hypothesis used for the purpose of pursuing further progress in research. Working hypotheses are frequently discarded, and often proposed with knowledge (and warning) that they are incomplete and thus false, with the intent of moving research in at least somewhat the right direction, especially when scientists are stuck on an issue and brainstorming ideas. A different meaning of the term ''hypothesis'' is used in formal logic, to deno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
