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Solid-phase electrical conductivity: Variable, [6] depending on the nature of the bonding: network solids in which all electrons are used for sigma bonds (e.g. diamond, quartz) are poor conductors, as there are no delocalized electrons. However, network solids with delocalized pi bonds (e.g. graphite) or dopants can exhibit metal-like conductivity.
Solids can be classified according to the nature of the bonding between their atomic or molecular components. The traditional classification distinguishes four kinds of bonding: [1] Covalent bonding, which forms network covalent solids (sometimes called simply "covalent solids") Ionic bonding, which forms ionic solids
This page was last edited on 20 July 2010, at 03:13 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may ...
In chemistry, a formula unit is the smallest unit of a non-molecular substance, such as an ionic compound, covalent network solid, or metal. [1] [2] It can also refer to the chemical formula for that unit. Those structures do not consist of discrete molecules, and so for them, the term formula unit is used.
α‑ P 3 N 5 and α′‑ P 3 N 5 are formed of a network structure of PN 4 tetrahedra with 2- and 3-coordinated nitrides, [7] [9] γ‑ P 3 N 5 is composed of both PN 4 and PN 5 polyhedra [8] while δ-P 3 N 5 is composed exclusively of corner- and edge-sharing PN 6 octahedra. [9] δ-P 3 N 5 is the most incompressible triphosphorus ...
The covalent radius of fluorine of about 71 picometers found in F 2 molecules is significantly larger than that in other compounds because of this weak bonding between the two fluorine atoms. [9] This is a result of the relatively large electron and internuclear repulsions, combined with a relatively small overlap of bonding orbitals arising ...
Metallic glasses, for example, are typically well described by the dense random packing of hard spheres, whereas covalent systems, such as silicate glasses, have sparsely packed, strongly bound, tetrahedral network structures. These very different structures result in materials with very different physical properties and applications.
However, they are distinguished from thermosets by the incorporation of dynamic covalent chemistry into the polymer network. When a stimulus (for example heat, light, pH, ...) is applied to the material, these dynamic bonds become active and can be broken or exchanged with other pending functional groups , allowing the polymer network to change ...