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Whereas SO 2 tends to be molecular and SeO 2 is a one-dimensional chain, TeO 2 is a cross-linked polymer. [5] SeO 2 is considered an acidic oxide: it dissolves in water to form selenous acid. [6] Often the terms selenous acid and selenium dioxide are used interchangeably. It reacts with base to form selenite salts containing the SeO 2−
Selenium can exist with oxidation state −2, +2, +4, +6. Se(II) is the dominant form in organoselenium chemistry. Se(II) is the dominant form in organoselenium chemistry. Down the group 16 column, the bond strength becomes increasingly weaker (234 kJ / mol for the C−Se bond and 272 kJ/mol for the C−S bond) and the bond lengths longer ( C ...
The common mineral selenite is not a selenium mineral, and contains no selenite ion, but is rather a type of gypsum (calcium sulfate hydrate) named like selenium for the moon well before the discovery of selenium. Selenium is most commonly found as an impurity, replacing a small part of the sulfur in sulfide ores of many metals.
In the selenium cycle it has been found that bacteria, fungi, and plants, especially species of Astragalus, metabolize the most oxidized forms of selenium, selenate or selenite, to selenide. It is also thought that microorganisms may be able to oxidize selenium of valence zero to selenium of valence +6.
Selenium was originally developed by Jason Huggins in 2004 as an internal tool at ThoughtWorks. [5] Huggins was later joined by other programmers and testers at ThoughtWorks, before Paul Hammant joined the team and steered the development of the second mode of operation that would later become "Selenium Remote Control" (RC).
Building structures or large nonbuilding structures (such as dams and bridges) are rarely subjected to destructive testing due to the prohibitive cost of constructing a building, or a scale model of a building, just to destroy it. Earthquake engineering requires a good understanding of how structures will perform at earthquakes. Destructive ...
Before any demolition activities can take place, there are many steps that must be carried out beforehand, including performing asbestos abatement, removing hazardous or regulated materials, obtaining necessary permits, submitting necessary notifications, disconnecting utilities, rodent baiting and the development of site-specific safety and ...
Water damage restoration can be performed by property management teams, building maintenance personnel, or by the homeowners themselves; however, contacting a certified professional water damage restoration specialist is often regarded as the safest way to restore water damaged property. Certified professional water damage restoration ...