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BeH 2 is usually formed as an amorphous white solid, but a hexagonal crystalline form with a higher density (~0.78 g/cm 3) was reported, [7] prepared by heating amorphous BeH 2 under pressure, with 0.5-2.5% LiH as a catalyst. Subunit of structure of BeH 2. Each Be is tetrahedral and each H is doubly bridging. [8]
The propensity for any two substances to form a solid solution is a complicated matter involving the chemical, crystallographic, and quantum properties of the substances in question. Substitutional solid solutions, in accordance with the Hume-Rothery rules, may form if the solute and solvent have: Similar atomic radii (15% or less difference)
Beryllium oxide (BeO), also known as beryllia, is an inorganic compound with the formula BeO. This colourless solid is an electrical insulator with a higher thermal conductivity than any other non-metal except diamond, and exceeds that of most metals. [12]
The other form resembles zinc iodide with interconnected adamantane-like cages. [4] In contrast, BeF 2 is a 3-dimensional polymer, with a structure akin to that of quartz. In the gas phase, BeCl 2 exists both as a linear monomer and a bridged dimer with two bridging chlorine atoms where the beryllium atom is 3-coordinate. [5]
Beryllium is an exception: It does not react with water or steam unless at very high temperatures, [10] and its halides are covalent. If beryllium did form compounds with an ionization state of +2, it would polarize electron clouds that are near it very strongly and would cause extensive orbital overlap, since
Beryllium fluoride has distinctive optical properties. In the form of fluoroberyllate glass, it has the lowest refractive index for a solid at room temperature of 1.275. Its dispersive power is the lowest for a solid at 0.0093, and the nonlinear coefficient is also the lowest at 2 × 10 −14.
At low temperatures, the electrons of solid materials can also organize into various electronic phases of matter, such as the superconducting state, with vanishing resistivity. Magnetic states such as ferromagnetism and antiferromagnetism can also be regarded as phases of matter in which the electronic and nuclear spins organize into different ...
The covalent bonds in this material form extended structures, but do not form a continuous network. With cross-linking, however, polymer networks can become continuous, and a series of materials spans the range from Cross-linked polyethylene , to rigid thermosetting resins, to hydrogen-rich amorphous solids, to vitreous carbon, diamond-like ...