Alkaline-earth metal

The alkaline earth metals have two valence electrons in their outermost shells. When one of these metals combines with a nonmetal, the alkaline earth metal loses both of its valence electrons and becomes a doubly positively charged ion. One example of this is the compound calcium fluoride (CaF2). When calcium combines with fluoride, it loses both of its valence electrons to the two fluorine atoms, thus becoming a doubly charged positive ion (Ca2+). This chapter provides a brief discussion of all of the 

Beryllium is the first element in the alkaline earth metals group, sitting to the right of the alkali metal lithium. In its pure form, this metal is rather hard and has a gray-white appearance. Of all of the metals, beryllium has the lowest density. It is also relatively rare. Although compounds and minerals containing beryllium are found 

Beryllium was discovered in 1798 by a chemist from France named Louis-Nicolas Vauquelin (1763-1829). Vauquelin was researching the mineral beryl. He discovered that beryl is the principal source of beryllium. Emeralds, along with the blue gem aquamarine, are crystals formed from beryl. 

As a pure metal, beryllium has few industrial uses. However, beryllium is transparent to X-rays, and is therefore used in the manufacture of windows for X-ray machines. 

Although it may not be valuable as a pure metal, beryllium is often mixed with other metals to form alloys that have industrial uses. One example is beryllium copper alloy, or beryllium bronze. This alloy is not only hard, but does not give off sparks when it is struck. This property makes it a useful material for electrical instruments and hammers that are used in explosive environments, such as in chemical laboratories that use hydrogen or factories that make rocket fuel. 

Since all isotopes of Fr are radioactive, it was not discovered until 1939 at the Curie Institute in Paris by Marguerite Perey, although the Russian chemist Dimitri Mendeleev predicted its existence. Its name derives from that of France, the country where it was discovered. 

Because of their metallic and alkaline properties, potassium and especially sodium are widely used in a variety of industrial processes both as metals and as compounds with various other elements. Lithium is rarely used, but does find application in lightweight alloys with magnesium. Rubidium and cesium are not commonly utilized industrially, except for some applications in electronics. Sodium and potassium are essential for life, sodium being the principal extracellular and potassium the major intracellular monovalent cations. The other alkali metals have no essential biological role, see ALSO Bunsen, Robert Cesium Davy, Humphry Francium Lithium Mendeleev, Dimitri Potassium Rubidium Sodium. 

Nechaev, L Jenkins, G. W. and Van Loon, Borin (1997). Chemical Elements The Exciting Story of Their Discovery and of the Great Scientists Who Found Them. Jersey City, NJ Parkwest Publications. 

Rossotti, Hazel (1998). Diverse Atoms Profiles of the Chemical Elements. New York Oxford University Press. 

Mark (2003). WebElements Periodic Table, Scholar Edition. WebElements Ltd. Additional information available from http //www.webelements.com . 

Dimeric structures have also been found for ate -complexes of magnesium. Bimetallic species such as LiMgPhs and Li2MgPli4 have been known since the pioneering work of Wittig et al. [192, 193]. Early investigations on these materials include H and Li NMR measurements and X-ray powder diffraction studies 

One report in the literature describes the preparation and structural characterization of a compound containing an unusual octaorganotrimagnesate. The compound [Mg2Me3(tacn)2]2[Mg3Mes], 220, is formed upon treatment of dime-thylmagnesium with the cyclic triamine ligand tacn (tacn = N,N, N -trimethyl- 

6 Supramolecular Self-Assembly Caused by Ionic Interactions 

Hydrolysis of Metal Ions, First Edition. Paul L Brown and Christian Ekberg. 

The beryllium ion has a relatively small ionic radius (0.35 A (Shannon and Prewitt, 1969)). As a consequence of this small size, its hydrolysis reactions begin to occur at a relatively low pH (about 5.3). Only the divalent ion exists in aqueous solution. 

There are only a few studies that have measured the solubility of the beryllium hydroxide and oxide phases, with the majority of the studies being conducted at 

From these solubility data, the logarithm of the constant for the following reaction at 25 °C 

Much of the data available for the stability constants of the monomeric hydrolysis species of beryUium(II) have been obtained at 20 and 25 C. However, two studies (Soboleva et cd., 1977 Renders and Anderson, 1987) obtained data at temperatures to 300 °C from solubUity measurements. 

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Forms water-soluble alkali and alkaline earth metal salts. Heating with KCN gives benzonitrile and phenol is formed by fusion with NaOH or KOH. Further sulphonation at 250°C gives benzene-1,3-disulphonic acid. 

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]). 

Group IIB and know that this means the group of elements zine. cadmium and mercury, whilst Group IIA refers to the alkaline earth metals beryllium, magnesium, calcium, barium and strontium. 

For the most part it is true to say that the chemistry of the alkali and alkaline earth metal compounds is not that of the metal ion but rather that of the anion with which the ion is associated. Where appropriate, therefore, the chemistry of these compounds will be discussed in other sections, for example nitrates with Group V compounds, sulphates with Group VI compounds, and only a few compounds will be discussed here. 

The elements in Group II of the Periodic Table (alkaline earth metals) are. in alphabetical order, barium (Ba). beryllium (Be), calcium (Ca). magnesium (Mg), radium (Ra) and strontium (Sr). 

The properties of lithium resemble those of the alkaline earth metals rather than those of the alkali metals. Discuss this statement. 

All the azides are potentially dangerous, and liable to detonate on heating, but those of the alkali and alkaline earth metals can be heated with caution if pure they then evolve pure nitrogen. 

The sulphates of the alkali and alkaline earth metals and man-ganese(II) are stable to heat those of heavier metals decompose on heating, evolving sulphur trioxide and leaving the oxide or the metal ... 

L = lanthanide), are indeed similar to the ions of the alkaline earth metals, except that they are tripositive, not dipositive. 

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

Uranium can be prepared by reducing uranium halides with alkali or alkaline earth metals or by reducing uranium oxides by calcium, aluminum, or carbon at high temperatures. The metal can also be produced by electrolysis of KUF5 or UF4, dissolved in a molten mixture of CaCl2 and NaCl. High-purity uranium can be prepared by the thermal decomposition of uranium halides on a hot filament. 

Its importance depends on the nuclear property of being readily fissionable with neutrons and its availability in quantity. The world s nuclear-power reactors are now producing about 20,000 kg of plutonium/yr. By 1982 it was estimated that about 300,000 kg had accumulated. The various nuclear applications of plutonium are well known. 238Pu has been used in the Apollo lunar missions to power seismic and other equipment on the lunar surface. As with neptunium and uranium, plutonium metal can be prepared by reduction of the trifluoride with alkaline-earth metals. 

Oxygen Acetaldehyde, acetone, alcohols, alkali metals, alkaline earth metals, Al-Ti alloys, ether, carbon disulflde, halocarbons, hydrocarbons, metal hydrides, 1,3,5-trioxane... 

Spectra of helium and the alkaline earth metal atoms... 

The fine structure of a — 5 transition of an alkaline earth metal is illustrated in Figure... 

So far we have considered only hydrogen, helium, the alkali metals and the alkaline earth metals but the selection rules and general principles encountered can be extended quite straightforwardly to any other atom. 

Processes rendered obsolete by the propylene ammoxidation process (51) include the ethylene cyanohydrin process (52—54) practiced commercially by American Cyanamid and Union Carbide in the United States and by I. G. Farben in Germany. The process involved the production of ethylene cyanohydrin by the base-cataly2ed addition of HCN to ethylene oxide in the liquid phase at about 60°C. A typical base catalyst used in this step was diethylamine. This was followed by liquid-phase or vapor-phase dehydration of the cyanohydrin. The Hquid-phase dehydration was performed at about 200°C using alkah metal or alkaline earth metal salts of organic acids, primarily formates and magnesium carbonate. Vapor-phase dehydration was accomphshed over alumina at about 250°C. 

The calculations indicate that the 8 subsheU should fiU at elements 119 and 120, thus making these an alkaH and alkaline earth metal, respectively. Next, the calculations point to the filling, after the addition of a 7t7 electron at element 121 of the inner 5 and (if subsheUs, 32 places in aU, which the author has termed the superactinide elements and which terminates at element 153. This is foUowed by the filling of the 7d subsheU (elements 154 through 162) and 8 subsheU (elements 163 through 168). 

Salt Formation. Salt-forming reactions of adipic acid are those typical of carboxylic acids. Alkali metal salts and ammonium salts are water soluble alkaline earth metal salts have limited solubiUty (see Table 5). Salt formation with amines and diamines is discussed in the next section. 

Chlorine reacts with alkaU and alkaline earth metal hydroxides to form bleaching agents such as NaOCl ... 

Arsenic pentafluoride can be prepared by reaction of fluorine and arsenic trifluoride or arsenic from the reaction of NF O and As (16) from the reaction of Ca(FS02)2 and H AsO (17) or by reaction of alkaH metal or alkaline-earth metal fluorides or fluorosulfonates with H AsO or H2ASO2F (18). 

Hexafluoroarsenic acid [17068-85-8] can be prepared by the reaction of arsenic acid with hydrofluoric acid or calcium fluorosulfate (29) and with alkaH or alkaline-earth metal fluorides or fluorosulfonates (18). The hexafluoroarsenates can be prepared directly from arsenates and hydrofluoric acid, or by neutrali2ation of HAsF. The reaction of 48% HF with potassium dihydrogen arsenate(V), KH2ASO4, gives potassium hydroxypentafluoroarsenate(V)... 

Because of the special stabiHty of the hexafluoroarsenate ion, there are a number of appHcations of hexafluoroarsenates. For example, onium hexafluoroarsenates (33) have been described as photoinitiators in the hardening of epoxy resins (qv). Lithium hexafluoroarsenate [29935-35-1] has been used as an electrolyte in lithium batteries (qv). Hexafluoroarsenates, especially alkaH and alkaline-earth metal salts or substituted ammonium salts, have been reported (34) to be effective as herbicides (qv). Potassium hexafluoroarsenate [17029-22-0] has been reported (35) to be particularly effective against prickly pear. However, environmental and regulatory concerns have severely limited these appHcations. 

Chemical Properties. In addition to the reactions Hsted in Table 3, boron trifluoride reacts with alkali or alkaline-earth metal oxides, as well as other inorganic alkaline materials, at 450°C to yield the trimer trifluoroboroxine [13703-95-2] (BOF), MBF, and MF (29) where M is a univalent metal ion. The trimer is stable below — 135°C but disproportionates to B2O2 and BF at higher temperatures (30). 

Precipitated (hydrated) siUca reacts vigorously with fluorosulfuric acid to give siUcon tetrafluoride [7783-61-1] (21), but glass (qv) is not attacked in the absence of moisture (20). Alkali and alkaline-earth metal chlorides are readily converted to fluorosulfates by treatment with fluorosulfuric acid (7,13,22,23). 

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