Metal periodic properties

Ion formation is only one pattern of chemical behavior. Many other chemical trends can be traced ultimately to valence electron configurations, but we need the description of chemical bonding that appears in Chapters 9 and 10 to explain such periodic properties. Nevertheless, we can relate important patterns in chemical behavior to the ability of some elements to form ions. One example is the subdivision of the periodic table into metals, nonmetals, and metalloids, first introduced in Chapter 1. 

Figure 6.6 summarizes different blocks, families, and areas of the periodic table. Most elements can be classified as metals. Metals are solid at room temperature, are good conductors of heat and electricity, and form positive ions. Moving across the table from left to right elements lose their metallic characteristics. The metalloids, also known as the semi-metals, have properties intermediate between metals and nonmetals. Because they display characteristics of both conductors and nonconductors, elements such as silicon and germanium find wide use in the semi-conductor industry. Non-metals are found on the far right of the periodic table. Nonmetals are poor conductors and are gases at room temperature. 

The large central block of the periodic table is occupied by the transition metals, which are mostly listed as Group B elements. Transition metals have properties that vary from extremely metallic, at the left side, to far less metallic, on the right side. The rightmost boundary of the metals is shaped like a staircase, shown in bold in Figure 4-1. 

Inulin can be modified to compounds that display good heavy metal complexing properties similar to ethylene diamine tetra-acetic acid (EDTA) but with better biodegradation properties (Bogaert et al., 1998). Inulin is first oxidized using sodium periodate to the dialdehyde, and then reduced to a polyol using Pt/C and hydrogen. The polyol can then be modified with carbon disulfide to form xanthate or with S03-pyridine to obtain an inulin sulfate. Alternatively, the dialdehyde can be animated with diaminoethane and sodium cyanoborohydride and the product reacted with monochloroacetic acid sodium salt to form carboxymethylamino inulin. Each of these compounds can be used to precipitate heavy metals. 

When 8-hydroxyquinoline and derivatives of bis(8-hydroxy-quinoline) react with metal ions, coordination complexes and polymers are formed, respectively, which exhibit improved thermal stability. This paper reviews the reaction of first-row transition metal ions with such ligands and their effect on the stabilization of these organic molecules. For the polymers containing divalent Mn, Co, Ni, Cu, or Zn the decomposition temperature is related to the periodic properties of the metal as well as the composition of the ligand to which the metal is coordinated. Trivalent chromium produces a crosslinked polymer when it reacts with bis(8-hydroxy-5-quinolyl)methane, and the thermogram for this polymer is also reported. 

Two categories of elements on the periodic table are the metals and the non-metals. Their properties are summarized in the chart below ... 

The chalcogens are one of the most interesting families in the periodic table. The first member, oxygen, is a gas with very un-metal-like properties. The next two members of the family, sulfur and selenium, are solids, with increasingly metallic properties. Tellurium, near the bottom of the family, looks and behaves very much like most metals. The slow change of properties, from less metal-like to more metal-like, occurs in all families in the periodic table. But the change is seldom as dramatic as it is in the chalcogens. 

Transition metals share properties such as electrical conductivity, luster, and malleability with other metals. There is little variation in atomic size, electronegativity, and ionization energy across a period. However, there are differences in properties among these elements, especially physical properties. For example, silver is the best conductor of electricity. Iron and titanium are used as structural materials because of their relative strength. 

Why do transition metals share properties with other transition metals in their period ... 

Across a period, the elements become less metallic and more nonmetallic with corresponding changes in chemical properties. The arrangement of the elements in the periodic table makes it easier to see trends in their properties within groups and across periods. Two important properties of elements are the size of their atoms and the ease (or lack of ease) with which they lose an electron. Both are functions of the periodic similarities of electronic configuration, causing both size and ease of electron loss to be periodic properties of the elements. 

In basic research, the chemistry of gold and organogold compounds merits special interest because of the unique position of gold in the periodic table, which is characterized by the highest electron affinity, electronegativity, and redox potential of all metals. These properties have their origin in a pronounced maximum in the relativistic contraction of the valence electron orbitals and associated effects. Several reviews on organogold chemistry have been published. ... 

The Periodic Table is divided into two sections by a stair-stepped line (Figure 2.4). The line starts under hydrogen, goes over to boron, and then stair-steps down one element at a time to astatine or radon, depending on which Periodic Table is used. The 81 elements to the left and below the stair-stepped line are metals. Metals make up about 75% of all the elements. Metals lose their outer-shell electrons easily to nonmetals when forming compounds. Metals are malleable (they can be flattened), ductile (they can be drawn into a wire), and conduct heat and electricity quite well. The farther to the left of the line you go, the more metallic the properties of the element the closer to the line, the less metallic the properties of the element. Metallic properties increase as you go down a column on the Periodic Table. All metals are solids, except gallium, mercury, francium, and cesium, which are liquids under normal conditions. 

The chemical and physical properties of all elements in a single group are similar. However, the elements become more metallic in nature as the period number increases. The chemical and physical properties of the elements tend to vary smoothly across a period. Elements in Group 1 are most metallic in character, and elements in Group 18 are the least metallic. The properties of the elements lying within the transition metal blocks are similar. This family similarity is even more pronounced in the lanthanides and actinides. 

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