Metals malleable property

The /3- and -phases are not unlike their component metals in properties such as luster, malleability, and electrical resistivity. The 7-phase, however, shows striking differences it is brittle and is associated with sharp maxima in electrical resistivity7 and diamagnetic susceptibility.8... 

Nickel is a ductile, malleable and ferromagnetic metal. Its properties are summarized in Table 6.7. 

Thus far, we ve discussed the sources, production, and properties of some important metals. Some properties, such as hardness and melting point, vary considerably among metals, but other properties are characteristic of metals in general. For instance, all metals can be drawn into wires (ductility) or beaten into sheets (malleability) without breaking into pieces like glass or an ionic crystal. Furthermore, all metals have a high thermal and electrical conductivity. When you touch a metal, it feels cold because the metal efficiently conducts heat away from your hand, and when you connect a metal wire to the terminals of a battery, it conducts an electric current. 

In metals, the typical structure has numerous free-floating valence electrons that surround positively charged metal ions. Since the electrons are free to flow, metals are good conductors of electricity. The atoms in a metal are not tightly bound together (as they are in a salt). Instead they are free to move past one another, which gives metals the property of malleability able to be shaped) and ductility (able to be drawn into thin wire). Ionic salts do not have these properties and will shatter if they are hammered or pulled. 

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. 

Metallic solids Recall from Chapter 8 that metallic solids consist of positive metal ions surrounded by a sea of mobile electrons. The strength of the metallic bonds between cations and electrons varies among metals and accounts for their wide range of physical properties. For example, tin melts at 232°C, but nickel melts at 1455°C. The mobile electrons make metals malleable—easily hammered into shapes—and ductile—easily drawn into wires. When force is applied to a metal, the electrons shift and thereby keep the metal ions bonded in their new positions. Read Everyday Chemistry at the end of the chapter to learn about shape-memory metals. Mobile electrons make metals good conductors of heat and electricity. Power lines carry electricity from power plants to homes and businesses and to the electric train shown in Figure 13-21a. 

Metals and alloys are malleable and ductile, and they conduct electricity. When a metal can be poimded or rolled into thin sheets, it is called malleable. Gold is an example of a malleable metal, as shown in Figure 9.11. A chimk of gold can be flattened and shaped by hammering imtil it is a thin sheet. Ductile metals can be drawn into wires. For example, copper can be pulled into thin strands of wire and used in electric circuits, as illustrated in Figure 9.11. Electrical conductivity is a measure of how easily electrons can flow through a material to produce an electric current. Metals such as silver are excellent conductors because there is low resistance to the movement of electrons in the metal. These properties— malleability, ductility, and electrical conductivity—are the result of the way that metal atoms bond with each other. 

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. 

Most of the elements are metals. Their general location in the periodic table is toward the left and bottom, as seen in the shading of the periodic table in Figure 2.14. Metals share a number of similarities in chemical and physical properties. Physically, metals are shiny, malleable, and ductile (meaning they can be pulled into wires). They also conduct electricity, so wires are always made from metals. Chemical properties can also be used to distinguish metals. Metallic elements tend to form cations in most of their compounds, for example. 

These metals have properties that you normally associate with the metals you encounter in everyday life. They are solid (with the exception of mercury, Hg, a liquid), shiny, good conductors of electricity and heat, ductile (they can be drawn into thin wires), and malleable (they can be easily hammered into very thin sheets). And all these metals tend to lose electrons easily (see Chapter 6). As you can see, the vast majority of the elements on the periodic table are classified as metals. 

The electron sea formed in metallic bonding gives metals their properties of high electrical and thermal conductivity, malleability, ductility, and luster. 

A number of the properties covered in this chapter are also given elsewhere in this volume. In this presentation, the properties of the actinide elements are taken as a whole and attempts are made to compare them with the properties of metallic elements occurring in other parts of the periodic table. The actinide metals are often thought to be exotic, because they tend to have properties that are difficult to explain by simple theoretical approaches that have been useful for simple metals. The properties of the actinide metals do in fact represent a severe test to the theoretical solid-state scientist, as do the other transition-metal series. But, like other metals, they are lustrous and may be malleable they have, among their several crystalline structures, some simple atomic arrangements and they have relatively low electrical resistivities and high thermal conductivities. 

Like the other transition elements that precede them in the periodic table, the group 11 metals can use d electrons in chemical bonding. Thus they can exist in different oxidation states, exhibit paramagnetism and color in some of their compounds, and form complex ions. They also possess to a high degree some of the distinctive physical properties of metals—malleability, ductility, and excellent electrical and thermal conductivity. 

Pure holmium has a metallic to bright silver luster. It is relatively soft and malleable, and is stable in dry air at room temperature, but rapidly oxidizes in moist air and at elevated temperatures. The metal has unusual magnetic properties. Few uses have yet been found for the element. The element, as with other rare earths, seems to have a low acute toxic rating. 

Tellurium also improves the properties of electrical steels by aiding in the magnetic anisotropy, malleable cast iron (77), and spheroidal (graphitic) cast irons (see also Metal surface TiiEATiffiNTs). 

Properties. Uranium metal is a dense, bright silvery, ductile, and malleable metal. Uranium is highly electropositive, resembling magnesium, and tarnishes rapidly on exposure to air. Even a poHshed surface becomes coated with a dark-colored oxide layer in a short time upon exposure to air. At elevated temperatures, uranium metal reacts with most common metals and refractories. Finely divided uranium reacts, even at room temperature, with all components of the atmosphere except the noble gases. The silvery luster of freshly cleaned uranium metal is rapidly converted first to a golden yellow, and then to a black oxide—nitride film within three to four days. Powdered uranium is usually pyrophoric, an important safety consideration in the machining of uranium parts. The corrosion characteristics of uranium have been discussed in detail (28). 

Main-group elements, 153t Malleability The ability to be shaped, as by pounding with a hammer characteristic of metals, 244 Maltose, 618-619 Manometer, 104 Maple syrup, 277-278 Mass An extensive property reflecting the amount of matter in a sample, 7. See also Amount, critical, 525... 

Though the mechanical properties of the various metals differ, all metals can be drawn into wires and hammered into sheets without shattering. Here we find a fourth characteristic property of metals they are malleable or workable. 

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