Alkaline earth metals beryllium, calcium, magnesium

Group 2A—Alkaline earth metals Beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra) are also lustrous, silvery metals, but are less reactive than their neighbors in group 1A. Like the alkali metals, the alkaline earths are never found in nature in the pure state. 

The elements in group 2 are the alkaline earth metals beryllium Be, magnesium Mg, calcium Ca, stronhum Sr, barium Ba and radium Ra. The last one, radium, is more interesting for its radioachve properties than for its similarity with the other alkaline earth elements. It will be described in Chapter 52 The Radioactive Elements. The others will be treated here and in Chapters 15 and 16. 

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. 

The alkaline-earth metals beryllium, magnesium, calcium, strontium, barium, radium. 

The second column from the left contains the alkaline earth metals, beryllium, magnesium, calcium, strontium, barium, and radium (Be, Mg, Ca, Sr, Ba, and Ra, respectively). Magnesium and calcium are present everywhere and are needed by our salty bodies and the salty bodies of our fellow creatures. Calcium is vital to bones, teeth, seashells, and exoskeletons. Calcium plays a critical role in the operation of our muscles as well as communication between cells. Because strontium is in this family, radioactive strontium, a fission product of certain atomic reactions, can be absorbed by the body and used as it would use calcium. Radium, another radioactive element, is also found in this family. 

Group 2 of the periodic table contains the alkaline earth metals beryllium, magnesium, calcium, strontium, barium, and radium. These elements are similar to the alkali metals in that they are shiny, ductile, and malleable. The alkaline earth metals have two electrons in their outermost shell. Although they are not as reactive as the alkali metals, the alkaline earth metals are rarely found pure in nature. 

Beryllium reacts with fused alkali halides releasing the alkali metal until an equilibrium is established. It does not react with fused halides of the alkaline-earth metals to release the alkaline-earth metal. Water-insoluble fluoroberyllates, however, are formed in a fused-salt system whenever barium or calcium fluoride is present. Beryllium reduces halides of aluminum and heavier elements. Alkaline-earth metals can be used effectively to reduce beryllium from its halides, but the use of alkaline-earths other than magnesium [7439-95 4] is economically unattractive because of the formation of water-insoluble fluoroberyllates. Formation of these fluorides precludes efficient recovery of the unreduced beryllium from the reaction products in subsequent processing operations. 

The Alkaline-Earth Metals.—Magnesium, calcium, strontium, and barium form essentially ionic bonds with the more nonmetallic elements. Beryllium bonds have the following amounts of ionic character Be—F, 79 percent Be—O, 63 percent Be—Cl, 44 percent Be—Br, 35 percent Be—I, 22 percent. 

Our theory regarding atomic size and reactivity holds true for the alkaline earth metals. As we move down a group on the periodic table, as the atomic size increases, the chemical reactivity increases. Calcium is more reactive than beryllium and magnesium. Neither the alkali metals nor the alkaline earth metals would be good candidates for jewelry making. We would not want to wear metal jewelry that might react violently to oxygen or water vapor in the air. 

Beryllium, magnesium, calcium, strontium, barium, and radium constitute Group 2 in the Periodic Table. These elements (or simply the Ca, Sr, and Ba triad) are often called alkaline-earth metals. Some important properties of group 2 elements are summarized in Table 12.5.1. 

A similar but less complete trend appears in the reactions of the alkaline earth metals with oxygen. Treatment with excess 02 yields monoxides in the cases of beryllium, magnesium, and calcium barium, however, forms the peroxide, Ba02, whereas strontium gives a mixture of monoxide and peroxide. 

Some of the halides of the alkaline earth metals have a similar identity problem. Calcium chloride and magnesium chloride have melting points almost as high as that of sodium chloride. Those compounds are clearly held together by ionic bonds. Beryllium chloride, on the other hand, melts at about half the temperature of table salt. And it boils at 520°C compared to salt s 1,465°C. The differences in properties are due to the partially covalent bond formed between beryllium and chlorine. 

Alkali metals lithium, sodium, potassium, rubidium, cesium, and francium. Metals such as sodium and potassium (the alkali metals) react violently with water—too violently to conduct experiments. The group 2 metals (also called alkaline earth metals) react less readily and can be used in the laboratory. Alkaline earth metals, including beryllium, magnesium, calcium, strontium, barium, and radium. 

Calcium, strontium, and barium react vigorously at 25°C. The less easily oxidized beryllium and magnesium show no observable reaction with water at 25°C, although magnesium reacts with boiling water. Table 18.7 summarizes various properties, sources, and preparations of the alkaline earth metals. 

Barium is a member of the alkaline earth metals. The alkaline earth metals make up Group 2 (IIA) of the periodic table. The other elements in this group are beryllium, magnesium, calcium, strontium, and radium. These elements tend to be relatively active chemically and form a number of important and useful compounds. They also tend to occur abundantly in Earth s crust in a number of familiar minerals such as aragonite, calcite, chalk, limestone, marble, travertine, magnesite, and dolomite. Alkaline earth compounds are widely used as building materials. 

Radium is a radioactive element in Group 2 (IIA) and Row 7 of the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Radium was discovered in 1898 by Marie Curie (1867-1934) and her husband, Pierre Curie (1859-1906). It was found in an ore of uranium called pitchblende. The alkaline earth metals also include beryllium, magnesium, calcium, strontium, and barium. 

Complete the following concept map using the following terms beryllium magnesium calcium, strontium, and barium alkaline earth metals. 

The alkaline earth metals show a wider range of chemical properties than the alkali metals. The IIA metals are not as reactive as the lA metals, but they are much too reactive to occur free in nature. They are obtained by electrolysis of their molten chlorides. Calcium and magnesium are abundant in the earth s crust, especially as carbonates and sulfates. Beryllium, strontium, and barium are less abundant. All known radium isotopes are radioactive and are extremely rare. 

The trend to increasing reactivity with increasing size of atom for the alkaline earth metals is illustrated by the reaction of the elements with water, as shown in Figure 8.7. Beryllium does not react with water. Magnesium reacts with hot water. But calcium reacts with water to form calcium hydroxide [Ca(OH)2], as shown by this equation. 

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