Alkaline earth metal

The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.Beryllium Be Atomic Number: 4 Atomic Weight: 9.012182 Melting Point: 1560.15 KBoiling Point: 2742 KSpecific mass: 1.85 g/cm3 Electronegativity: 1.57Magnesium Mg Atomic Number: 12 Atomic Weight: 24.3050 Melting Point: 923.15 K Boiling Point: 1363 KSpecific mass: 1.738 g/cm3 Electronegativity: 1.31Calcium Ca Atomic Number: 20 Atomic Weight: 40.078 Melting Point: 1112.15 K Boiling Point: 1757 KSpecific mass: 1.54 g/cm3 Electronegativity: 1Strontium Sr Atomic Number: 38 Atomic Weight: 87.62 Melting Point: 1042.15 K Boiling Point: 1655 KSpecific mass: 2.64 g/cm3 Electronegativity: 0.95Barium Ba Atomic Number: 56 Atomic Weight: 137.327 Melting Point: 1002.15 K Boiling Point: 2170 KSpecific mass: 3.594 g/cm3 Electronegativity: 0.89Radium Ra Atomic Number: 88 Atomic Weight: Melting Point: 973.15 K Boiling Point: 2010 K Specific mass: 5.5 g/cm3 Electronegativity: 0.9 The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. Structurally, they have in common an outer s- electron shell which is full;that is, this orbital contains its full complement of two electrons, which these elements readily lose to form cations with charge +2, and an oxidation state of +2. All the discovered alkaline earth metals occur in nature, although radium occurs only through the decay chain of uranium and thorium and not as a primordial element. Experiments have been conducted to attempt the synthesis of element 120, the next potential member of the group, but they have all met with failure. As with other groups, the members of this family show patterns in their electronic configuration, especially the outermost shells, resulting in trends in chemical behavior: Most of the chemistry has been observed only for the first five members of the group. The chemistry of radium is not well-established due to its radioactivity; thus, the presentation of its properties here is limited. The alkaline earth metals are all silver-colored and soft, and have relatively low densities, melting points, and boiling points. In chemical terms, all of the alkaline earth metals react with the halogens to form the alkaline earth metal halides, all of which are ionic crystalline compounds (except for beryllium chloride, which is covalent). All the alkaline earth metals except beryllium also react with water to form strongly alkaline hydroxides and, thus, should be handled with great care. The heavier alkaline earth metals react more vigorously than the lighter ones. The alkaline earth metals have the second-lowest first ionization energies in their respective periods of the periodic table because of their somewhat low effective nuclear charges and the ability to attain a full outer shell configuration by losing just two electrons. The second ionization energy of all of the alkaline metals is also somewhat low. Beryllium is an exception: It does not react with water or steam, 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 has a high charge density. All compounds that include beryllium have a covalent bond. Even the compound beryllium fluoride, which is the most ionic beryllium compound, has a low melting point and a low electrical conductivity when melted. All the alkaline earth metals have two electrons in their valence shell, so the energetically preferred state of achieving a filled electron shell is to lose two electrons to form doubly charged positive ions. The alkaline earth metals all react with the halogens to form ionic halides, such as calcium chloride (CaCl2), as well as reacting with oxygen to form oxides such as strontium oxide (SrO). Calcium, strontium, and barium react with water to produce hydrogen gas and their respective hydroxides, and also undergo transmetalation reactions to exchange ligands.