Variable Valency & Covalency in Chemistry from Chapter 8 / Lesson 8 15K In this lesson, we first review the meaning of valence and covalence for the elements. We then describe how some elements can have multiple different valences and covalences. In other words, some elements do not alway...
What is the valency of hydrogen? For oxidation, when is O2 a -1 charge, and when is it a -2 charge? How do you calculate the oxidation number of complex compounds? Consider the following ion: XF2-2. What is the oxidation number assigned to element 'X'?
Ammonium metavanadate is the inorganic compound with the formula NH₄VO₃. It is a white salt, although samples are often yellow owing to impurities of V₂O₅. It is an important intermediate in the purification of vanadium. What is the meaning of vanadate? :a salt derived from vanadi...
Catenation isthe ability of an atom to form bonds with other atoms of the same element. It is exhibited by both carbon and silicon. Compare the ability of catenation of the two elements. What is tetravalency and catenation? Catenation is the self-linking property of carbon i.e carbon atoms...
The scientistpouredthe acid into a safe container. However, when the meaning ofpouris “to rain heavily,”pourbecomes an impersonal verb. It’spouringoutside, so I’m taking an umbrella. What is valency? In grammar, the valency or valence of a verb refers to how many elements in a sente...
The meaning of an ‘element’ is a favourite topic for argument among off-duty chemists. We agree (right?) that hydrogen is an element – but what do we mean by that? Is molecular hydrogen gas an element? Or the isolated hydrogen atom? Or are we referring not to some actual substance...
These variables are dimensional rather than categorical in the sense that they are ordinal and continuous, meaning that people can vary from one another in terms of multiple degrees of severity of symptoms or similarity to a prototype. For example, a person who has 6 out of 9 symptoms is ...
The experts then gener- ated a set of items that represented each of these dimen- sions. The initial set of items for each domain was reduced by consensus to a final set of 3 items, each comprised of two items with positive valency (e.g., "The things I do make a difference to my...
In chemistry, a related notion is the valency of an atom, i.e., the number of bonds (counting bond order) that can be formed by an atom. Each type of atom/moiety therefore has a fixed degree that we can think of as the number of halfbonds. Each of these may bind to other ...
An act of giving welcome. Hospitable (`hospitable' is usually followed by `to') having an open mind; Hospitable to new ideas Open to suggestions Welcoming Very cordial; A welcoming smile Common Curiosities Do "hospitable" and "welcoming" have the same meaning? They both relate to friendliness...