Bài giảng cung cấp cho người học các kiến thức: Nhóm IA, tính kim loại, số oxi hóa, thế điện cực, tính chất lý học, tính chất hóa học,. Hi vọng đây sẽ là một tài liệu hữu ích dành cho các bạn sinh viên đang theo học môn dùng làm tài liệu học tập và nghiên cứu. chi tiết nội dung tài liệu. | THE S-BLOCK ELEMENTS Introduction Modern chemical knowledge is based largely on principles that answer the “why” as well as the “how-to.” In the remaining chapters, we will emphasize facts and applications, but we will refer to underlying principles repeatedly. Four of the 14 elements that comprise the s-block elements are somewhat unusual cases, although not all for the same reason. Hydrogen is the simplest element, with one proton and one electron, and its behavior is rather special. Helium lies in the s-block but its electron configuration fits with the noble gases, and it will be considered in the next chapter. Francium and radium are highly radioactive and we will not consider them further. GROUP IA: THE ALKALI METALS Spodumene LiAl(SiO3)2 The Alkali Metals Discoveries are recent. Sodium and potassium (1807) by electrolysis. Cesium (1860) and rubidium (1861) from emission spectra. Francium (1939) from actinium radioactive decay. Most salts are water soluble. Natural brines are good sources. Natural deposits allow mining of solids. Flame Colors Properties and Trends in Group 1A The Group 1A metals exhibit regular trends for a number of properties. Irregular trends suggest that factors are working against each other in determining a property (such as the density “discrepancy” between sodium and potassium). The alkali metals have two notable physical properties: they are all soft and have low melting points. When freshly cut, the alkali metals are bright and shiny—typical metallic properties. The metals quickly tarnish, however, as they react with oxygen in the air. Diagonal Relationships:The Special Case of Lithium In some of its properties, lithium and its compounds resemble magnesium and its compounds. Lithium carbonate, fluoride, hydroxide, and phosphate are much less water soluble than those of other alkali metals. Lithium is the only alkali metal that forms a nitride (Li3N). When it burns in air, lithium forms a normal oxide (Li2O) rather than a peroxide or | THE S-BLOCK ELEMENTS Introduction Modern chemical knowledge is based largely on principles that answer the “why” as well as the “how-to.” In the remaining chapters, we will emphasize facts and applications, but we will refer to underlying principles repeatedly. Four of the 14 elements that comprise the s-block elements are somewhat unusual cases, although not all for the same reason. Hydrogen is the simplest element, with one proton and one electron, and its behavior is rather special. Helium lies in the s-block but its electron configuration fits with the noble gases, and it will be considered in the next chapter. Francium and radium are highly radioactive and we will not consider them further. GROUP IA: THE ALKALI METALS Spodumene LiAl(SiO3)2 The Alkali Metals Discoveries are recent. Sodium and potassium (1807) by electrolysis. Cesium (1860) and rubidium (1861) from emission spectra. Francium (1939) from actinium radioactive decay. Most salts are water soluble. Natural brines are .
