Search results
Results From The WOW.Com Content Network
The Lorentz rule was proposed by H. A. Lorentz in 1881: [5] = + The Lorentz rule is only analytically correct for hard sphere systems. Intuitively, since , loosely reflect the radii of particle i and j respectively, their averages can be said to be the effective radii between the two particles at which point repulsive interactions become severe.
A critical pair arises in a term rewriting system when two rewrite rules overlap to yield two different terms. In more detail, (t 1, t 2) is a critical pair if there is a term t for which two different applications of a rewrite rule (either the same rule applied differently, or two different rules) yield the terms t 1 and t 2.
Hume-Rothery rules, named after William Hume-Rothery, are a set of basic rules that describe the conditions under which an element could dissolve in a metal, forming a solid solution. There are two sets of rules; one refers to substitutional solid solutions, and the other refers to interstitial solid solutions.
Bent's rule addresses disparities between the observed and idealized geometries. [3] According to Bent's rule, a central atom bonded to multiple groups will rehybridize so that orbitals with more s character are directed towards electropositive groups, and orbitals with more p character will be directed towards groups that are more electronegative.
The valence is the combining capacity of an atom of a given element, determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of 2; and in hydrogen chloride, chlorine has a valence of 1.
There is the qualitative rule that states that the greater the difference in the electronegativity of two metals, the greater the heat of formation - and hence the stability. Then there is the Hume-Rothery rule , which states that two metals that differ by more than 15% in their atomic radius will not form substitutional solid solutions.
The 18-electron rule is a chemical rule of thumb used primarily for predicting and rationalizing formulas for stable transition metal complexes, especially organometallic compounds. [1] The rule is based on the fact that the valence orbitals in the electron configuration of transition metals consist of five ( n −1)d orbitals, one n s orbital ...
Matched molecular pair analysis (MMPA) is a method in cheminformatics that compares the properties of two molecules that differ only by a single chemical transformation, such as the substitution of a hydrogen atom by a chlorine one. Such pairs of compounds are known as matched molecular pairs (MMP).