Alkaline earth metals chemical properties

Calcium, Ca 40.078 2 Chemically reactive alkaline earth metal with properties similar to those of magnesium... 

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). 

Strontium [7440-24-6] Sr, is in Group 2 (IIA) of the Periodic Table, between calcium and barium. These three elements are called alkaline-earth metals because the chemical properties of the oxides fall between the hydroxides of alkaU metals, ie, sodium and potassium, and the oxides of earth metals, ie, magnesium, aluminum, and iron. Strontium was identified in the 1790s (1). The metal was first produced in 1808 in the form of a mercury amalgam. A few grams of the metal was produced in 1860—1861 by electrolysis of strontium chloride [10476-85-4]. 

The elements in the second column of the table (Group 2) are the alkaline earth metals. These resemble the alkali metals in their appearance, but they have different chemical properties. For example, each of these metals... 

Addition of an alkali metal oxide as a "network modifier to the "network former causes pH sensitivity, i.e., small amounts of alkali metal induce superficial gel layer formation as a merely local chemical attack and so with limited alkali error larger amounts will result in more pronounced dissolving properties of the glass up to complete dissolution, e.g., water-glass with large amounts of sodium oxide. Simultaneous addition of an alkaline earth metal oxide, however, diminishes the dissolution rate. Substitution of lithium for sodium in pH-sensitive glass markedly reduces the alkali error. 

Although zinc is formally a 4-block element, some of its chemical properties are similar to those of the alkaline earth metals, especially those of magnesium. This is mainly due to zinc s exclusive exhibition of the +2 oxidation state in all its compounds and its appreciable electropositive character. With a standard potential of —0.763 V, zinc is considerably more electropositive than copper and cadmium. 

Some physical and chemical properties of the alkaline earth metals are shown in Table II. It can be seen that beryllium is significantly different from the elements below it in the periodic table in most respects. The fact that the density of beryllium is greater than that of magnesium is perhaps surprising, but can be understood by noting that magnesium is both a more massive and a larger atom. The density of beryllium is to be compared to that of iron (7.9 g cm-3), titanium (4.5 g cm-3), and aluminum (2.7 g cm-3). 

Some Physical and Chemical Properties of the Alkaline Earth Metals ... 

Lithium metal is highly reactive but less so than other alkah metals. Its chemical properties, however, are more like those of the alkaline earth metals. 

The periodic system developed from Bohr s atomic theory is of the greatest importance in chemical science because it demonstrates that the properties of the elements depend on their positions in the system. It is immediately apparent that chemical valency depends on the number of loosely-bound electrons in the atom. Thus, the alkali metals have one such electron while the divalent alkaline-earth metals have two, etc. Valency is therefore closely connected with electronic structure and provides the foundation for the modern theory of the chemical bond, the basis of which is to be found in the coupling or transfer of the valency electrons. 

In many of its chemical properties, radium is like the elements magnesium, caldum, strontium and barium, and it is placed in group 2, as is consistent with its 6s26pcls2 electron configuraUon. Its sulfate (Ksp — 4.2 a 10-1 ) is even more insoluble in water than barium sulfate, with which it is conveniently coprecipitated, Like barium and other alkaline earth metals, it forms a soluble chloride (X p = 0,4) and bromide, which can also be obtained as dihydrates, Radium also resembles the other group 2 elements in forming an insoluble carbonate and a very slightly soluble lodate (Xsp = 8.8 x 1(T10). 

Comparison of the properties of metal alkoxides with their structures permits a conclusion that the polymeric nature does not always lead to chemical inertness. The major role appears to be played by the nature of the M-OR bonding. Solubility in alcohols and liquid ammonia of the methoxides of alkaline and alkaline earth metals and that in hydrocarbons ofthe isopropoxides of K, Rb, Cs (isostructural with the corresponding methoxides), and also M(OC2H4OMe)n, M = Pb, Bi indicates the easy oligomerization due to solvation or chelation. At the same time the methoxides and ethoxides of Al, Cr, Fe, and so on, forming the strongest covalent bonds in the [MOs/6] octahedra (and not prone to solvation in alcohols), appear almost inert. They can be dissolved only due to complexation or partial destruction with formation ofoxobridges. 

Research the common physical and chemical properties for each family (a vertical column) in the periodic table. The families to consider are alkali metals, alkaline earth metals, inert gases, halogens, and transition metals. 

Common chemical properties The alkali metals are so chemically reactive that they are never found free in nature. Sodium and potassium react explosively with water to produce hydrogen gas. The alkaline earth metals are not quite as reactive as the alkali metals. The alkali metals react with water but not explosively. The transition metals are generally the least reactive of all the metals. However, when they combine with other elements, they form a large variety of colored compounds. Chromium oxide is green, titanium oxide and zinc oxide are white, manganese oxide is purple, and iron oxide is ochre. 

A column of the periodic table is called a family. Some families have special names. Group IA elements are called alkali metals, group IIA elements are called alkaline earth metals, group VIIA elements are called halogens, and group VIIIA elements are called the noble gases. The group B elements are called transition elements. Elements with atomic numbers from 58 to 71 are called lanthanides, and elements with atomic numbers from 90 to 103 are called actinides. Families have similar chemical and physical properties. For example, the alkali metals are soft metals at room temperature they are shiny, conduct... 

The transition metals are our premier metals for jewelry making. They have electron configurations that are different from the alkali metals and the alkaline earth metals. Therefore, transition metals exhibit different chemical and physical properties. It is necessary to determine just where electrons reside in transition-metal atoms so we can understand the properties of transition metals and how they bond. To understand these properties and manners of bonding, we must revisit the electron cloud atomic model. 

Figure 4.3 Doctors illuminate the intestines of a patient with the help of the alkaline earth metal barium. The patient drinks a concoction of barium sulfate that lines the stomach and intestines. Barium s chemical properties allow it to absorb X-rays, highlighting any problem areas.

Clay minerals and clay colloids are the products of the advanced weathering of primary silicates. They are comprised mainly of silica and alumina, often with appreciable amounts of alkali and alkaline earth metals and iron. Most also have varying amounts of water bound to their surfaces and can take on a variety of different chemical and physical properties depending on the amount of water adsorbed. They have the ability to exchange or bind cations and anions and are capable of complex formation with a wide variety of organic molecules. 

It was found that the linking of styryl dye fragment to benzocrown ether results in novel photochromic compounds CESD (Crown Ether Styryl Dyes) possessing interesting physico-chemical properties (Scheme 1) [13], The dyes are intensively colored and show significant hypsochromic shifts upon complexation with alkaline earth metal cations in acetonitrile solution. Reversible photochemical reaction E,Z-isomerization is observed for both dyes and their complexes. 

Indicates the pore space available for water and roots influenced by soil composition (mineral content, mineral type, and organic matter) and soil texture Affects adsorption of the chemical Affects the surface area where adsorption can take place Influences partitioning and availability of chemicals Affects ability of a soil to transmit water or air Dictates the porosity of the soil Affects the form, reactivity, solubility, availability, and toxicity of some contaminants Affects the toxicity of some substances (mainly heavy metals) with binding or antagonistic mechanisms, for example, by alkaline-earth metals and aluminum Organic matter content, type, and % carbon Influences soil sorption properties for heavy metals and... 

Potassium ruthenocyanide crystallises in square pseudo-rhombic plates, isomorphous with the corresponding ferro- and osmo-cyanides.2 Its solution in water yields no precipitate with salts of the alkaline earth metals as their ruthenocyanides are soluble. Ferric chloride gives a rich purple precipitate resembling Prussian blue in its chemical properties. Soluble in pure w ater it is precipitated by salts or alcohol. When precipitated in cotton fibre it adheres well, imparting its own beautiful colour. Alkalies decompose the salt, which, however, is re-formed on addition of dilute acid. This constitutes a useful test for ruthenocyanides. 

VH.16 BERYLLIUM, Be (At 9 01) Beryllium is a greyish-white, light but very hard, brittle metal. It dissolves readily in dilute acids. In its compounds beryllium is divalent, otherwise it resembles closely aluminium in chemical properties it also exhibits resemblances to the alkaline earth metals. The salts react acid in aqueous solution, and possess a sweet taste (hence the name glucinum formerly given to the element). Beryllium compounds are highly poisonous. 

Rare earth elements have similar configurations in the two outermost shells. They exhibit typical metallic properties in chemical reactions. They tend to lose three electrons and exhibit a 3+ valence state. From the Periodic Table of the elements, rare earth elements are classed as less reactive than alkali metals and alkaline earth metals but more reactive than other metals. They should be stored in an inert liquid otherwise they will be oxidized and lose their metal luster. The metal reactivity increases gradually from scandium to lanthanum and decreases gradually from lanthanum to lutetium. That is to say, lanthanum is the most reactive metal of the 17 rare earth elements. Rare earth metals can react with water and release hydrogen. They react more vigorously with acids but do not react with bases. 

H (a Be(OH)42 (aoxidizing agent and Be is the reducing agent. 61. Strontium and calcium are both alkaline earth metals, so both have similar chemical properties. 

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