Metal alkali, earth alkaline

True metals alkali, alkaline earth metals, Al, Cu, Ag, Au, etc., having a high specific electrical conductivity (OhnG cm l) k = 105—106 and crystal structures of high symmetry and coordination numbers (CN = 8-12). 

An interesting related feature shown by several alloys of the more basic metals (alkali, alkaline earths) with many /5-block (13th, 14th, 15th groups) elements, and,... 

A comprehensive screening study to identify optimal release thermodynamics should include both mixed metal amine salts as well as low concentration dopants. It is, however, not practically possible due to the large number of possible combinations. Limiting the potential elements to 3d and 4d transition metals, alkali, alkaline earth metals, and halides down to the sixth period of the periodic table, the number of candidate structures with just two different cations and two different anions in a super cell of 8 formula units is almost 2 million. An intelligent screening method is therefore needed to cut down the number of calculations e.g., a genetic algorithm. 

One current limitation of orbital-free DFT is that since only the total density is calculated, there is no way to identify contributions from electronic states of a certain angular momentum character /. This identification is exploited in non-local pseudopotentials so that electrons of different / character see different potentials, considerably improving the quality of these pseudopotentials. The orbital-free metliods thus are limited to local pseudopotentials, connecting the quality of their results to the quality of tlie available local potentials. Good local pseudopotentials are available for the alkali metals, the alkaline earth metals and aluminium [100. 101] and methods exist for obtaining them for other atoms (see section VI.2 of [97]). 

Alkali alkaline earth metal enolates tend to be aggregates- complicates stereo selection models. 

Table 14. Alkali Metal and Alkaline-Earth Titanates...

Further dechlorination may occur with the formation of substituted diphenyhnethanes. If enough aluminum metal is present, the Friedel-Crafts reactions involved may generate considerable heat and smoke and substantial amounts of hydrogen chloride, which reacts with more aluminum metal, rapidly forming AlCl. The addition of an epoxide inhibits the initiation of this reaction by consuming HCl. Alkali, alkaline-earth, magnesium, and zinc metals also present a potential reactivity hazard with chlorinated solvents such as methylene chloride. 

Fatty-acid soaps Alkali, alkaline earth, and other metal soaps sodium stearate aluminum stearate Gear oils paper stock paper sizing glue solutions... 

No attempt should be made to purify perchlorates, except for ammonium, alkali metal and alkaline earth salts which, in water or aqueous alcoholic solutions are insensitive to heat or shock. Note that perchlorates react relatively slowly in aqueous organic solvents, but as the water is removed there is an increased possibility of an explosion. Perchlorates, often used in non-aqueous solvents, are explosive in the presence of even small amounts of organic compounds when heated. Hence stringent care should be taken when purifying perchlorates, and direct flame and infrared lamps should be avoided. Tetra-alkylammonium perchlorates should be dried below 50° under vacuum (and protection). Only very small amounts of such materials should be prepared, and stored, at any one time. 

Among the alkali metals, Li, Na, K, Rb, and Cs and their alloys have been used as exohedral dopants for Cgo [25, 26], with one electron typically transferred per alkali metal dopant. Although the metal atom diffusion rates appear to be considerably lower, some success has also been achieved with the intercalation of alkaline earth dopants, such as Ca, Sr, and Ba [27, 28, 29], where two electrons per metal atom M are transferred to the Cgo molecules for low concentrations of metal atoms, and less than two electrons per alkaline earth ion for high metal atom concentrations. Since the alkaline earth ions are smaller than the corresponding alkali metals in the same row of the periodic table, the crystal structures formed with alkaline earth doping are often different from those for the alkali metal dopants. Except for the alkali metal and alkaline earth intercalation compounds, few intercalation compounds have been investigated for their physical properties. 

In all of these alkali-metal and alkaline earth-metal orthophosphates there are discrete, approximately regular tetrahedral PO4 units in... 

Many of the ionic fiuorides of M, M and M dissolve to give highly conducting solutions due to ready dissociation. Some typical values of the solubility of fiuorides in HF are in Table 17.11 the data show the expected trend towards greater solubility with increase in ionic radius within the alkali metals and alkaline earth metals, and the expected decrease in solubility with increase in ionic charge so that MF > MF2 > MF3. This is dramatically illustrated by AgF which is 155 times more soluble than AgF2 and TIF which is over 7000 times more soluble than TIF3. 

The C102 ion is nonlinear, as expected, and X-ray studies of NH4CIO2 (at —35°) and of AgC102 lead to the dimensions Cl-O 156 pm, angle O-Cl-O 11 r. The chlorites of the alkali metals and alkaline earth metals are colourless or pale yellow. Heavy metal chlorites tend to explode or detonate when heated or struck (e.g. those of Ag+, Hg+, T1+, Pb + and also those of Cu + and NH4+). Sodium chlorite is the only one to... 

On the other hand, Bartsch et al. have studied cation transports using crown ether carboxylic acids, which are ascertained to be effective and selective extractants for alkali metal and alkaline earth metal cations 33-42>. In a proton-driven passive transport system (HC1) using a chloroform liquid membrane, ionophore 31 selectively transports Li+, whereas 32-36 and 37 are effective for selective transport of Na+ and K+, respectively, corresponding to the compatible sizes of the ring cavity and the cation. By increasing the lipophilicity from 33 to 36, the transport rate is gradually... 

The person whose name is most closely associated with the periodic table is Dmitri Mendeleev (1836-1907), a Russian chemist. In writing a textbook of general chemistry, Mendeleev devoted separate chapters to families of elements with similar properties, including the alkali metals, the alkaline earth metals, and the halogens. Reflecting on the properties of these and other elements, he proposed in 1869 a primitive version of today s periodic table. Mendeleev shrewdly left empty spaces in his table for new elements yet to be discovered. Indeed, he predicted detailed properties for three such elements (scandium, gallium, and germanium). By 1886 all of these elements had been discovered and found to have properties very similar to those he had predicted. 

Reactions of Alkali Metals and Alkaline Earth Metals... 

Ground state The lowest allowed energy state of a species, 137 Group 1 metal. See Alkali metal Group 2 metal See Alkaline earth metal Group A vertical column of the periodic table, 31... 

Vaporization, molar heat of, 66 alkali metals, 94 alkaline earths, 381 copper, 67 chlorine, 67 inert gases, 105 metals, 305 neon, 67... 

Figure 4.19. Experimental work function values, for the 3d, 4d and 5d series including the alkali, alkaline-earth, and noble metals for polycrystalline surfaces (open circles) and for single crystal surfaces (filled circles).53 Reprinted with permission from the American Physical Society.

Now consider strong and weak bases. The common strong bases are oxide ions and hydroxide ions, which are provided by the alkali metal and alkaline earth metal oxides and hydroxides, such as calcium oxide (see Table J.l). As we have seen,... 

The high temperatures of coal char oxidation lead to a partial vaporization of the mineral or ash inclusions. Compounds of the alkali metals, the alkaline earth metals, silicon, and iron are volatilized during char combustion. The volatilization of silicon, magnesium, calcium, and iron can be greatly enhanced by reduction of their refractory oxides to more volatile forms (e.g., metal suboxides or elemental metals) in the locally reducing environment of the coal particle. The volatilized suboxides and elemental metals are then reoxidized in the boundary layer around the burning particle, where they subsequently nucleate to form a submicron aerosol. 

In addition to having similar electron configurations, some blocks have common chemical characteristics, too. The block of elements on the far left of the illustration, for example, are all metals. The two groups in the block are called the alkali metals (first column) and alkaline earth metals (second column). The alkali metals are remarkably similar soft, silvery, highly reactive metals. The alkaline earth metals form another distinctive group that are much harder that the alkaline metals and have higher melting points. 

Dabek-Zlotorzynska, E. and Dlouhy, J. F., Simultaneous determination of alkali, alkaline-earth metal cations and ammonium ion environmental samples by gradient ion chromatography, /. Chromatogr., 638, 35, 1993. 

The quantity dyl3 In a2 at the potential of the electrocapillary maximum is of basic importance. As the surface charge of the electrode is here equal to zero, the electrostatic effect of the electrode on the ions ceases. Thus, if no specific ion adsorption occurs, this differential quotient is equal to zero and no surface excess of ions is formed at the electrode. This is especially true for ions of the alkali metals and alkaline earths and, of the anions, fluoride at low concentrations and hydroxide. Sulphate, nitrate and perchlorate ions are very weakly surface active. The remaining ions decrease the surface tension at the maximum on the electrocapillary curve to a greater or lesser degree. 

In its compounds, the oxidation number of every alkali metal and alkaline earth metal is equal to its group number. 

Alkali metals, or Alkaline earth metals (not magnesium)... 

Active metal. The selection of active metal is also a critical factor. For polar intermetallics and Zintl phases, alkali, alkaline-earth, and rare-earth elements have... 

Following the original paper, reports of the synthesis of new crowns and crown-like molecules proliferated. A typical property of these systems is their ability to form stable complexes with the alkali metal and alkaline earth ions. Prior to the synthesis of the crowns, the coordination chemistry of the above ions with organic ligands had received very little attention. A further impetus to the study of such complexes was the recognition of the important role of Na+, K+, Mg2+ and Ca2+ ions in biological systems. 

In another category of template synthesis, ethylene oxide is cyclized in the presence of BF3 and alkali, alkaline earth, or transition ions as their fluoroborate, fluorophosphate or fluoroantimonate salts - see [4.4], This procedure yields cyclic tetramers, pentamers and/or hexamers with the particular product(s) obtained being quite dependent on the metal present. Thus Ca(BF4)2 gives a 50% yield of tetramer, Cu(BF4)2 and Zn(BF4)2 give the pentamer in 90% yield, whereas Rb(BF4) and Cs(BF4) yield exclusively hexamer (Dale Daasvatn, 1976). 

In water, the relatively low stability of the alkali metal and alkaline earth cryptates (except those for which there is a near-optimal fit of the cation in the intramolecular cavity) has resulted in difficulties in undertaking a wide-ranging kinetic study in this solvent. However, in non-aqueous media, the stability constants are larger and most of the studies have been performed in such media. 

The chapter on kinetics and mechanisms of complex formation and ligand substitution at alkali metal and alkaline earth cations elsewhere in this volume provides context and complementary discussion of these processes in relation to calcium. 

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