Periodic table precious metals

Why Do We Need to Know This Material The d-block metals are the workhorse elements of the periodic table. Iron and copper helped civilization rise from the Stone Age and are still our most important industrial metals. Other members of the block include the metals of new technologies, such as titanium for the aerospace industry and vanadium for catalysts in the petrochemical industry. The precious metals—silver, platinum, and gold—are prized as much for their appearance, rarity, and durability as for their usefulness. Compounds of d-block metals give color to paint, turn sunlight into electricity, serve as powerful oxidizing agents, and form the basis of some cancer treatments. 

The 76 elements geochemical maps show the distribution of all elements in the periodic table, especial for rare and dispersive and precious metals elements. 

Figure 4.12. The position in the Periodic Table of a few classes of commercially important metals. L Light metals, R Refractory metals, F Ferro alloy metals, P Precious metals, C Coinage metals and S Soft solder metals.

Most catalytic metals and metal oxides are derived from Group VIII of the periodic table. Of special importance are Fe, Co, Ni, Rh, Pd, and Pt but also of importance are Cu and Ag in Group lb, V in Group Vb, and Cr and Mo in Group Vlb. Three of the precious metals Rh, Pd, and Pt are extensively used in many industries due to their extremely high activity and selectivity. They are rare in nature and... 

Gold lies in the middle of the periodic table. The periodic table is a chart that shows how elements are related to one another. Gold is a heavy metal in a group known as the transition metals. Gold is also known as a precious metal (as are platinum and silver). 

Silver is also classified as a precious metal. Precious metals are not very abundant in Earth s crust. They are attractive and not very chemically active. These properties make the metal desirable in jewelry, coins, and art. About a half dozen metals near silver in the periodic table are also precious metals. These include gold, platinum, palladium, rhodium, and iridium. 

Although the alchemists failed to find a method for the transmntation of base metals into precious metals, a number of important chemical processes resulted from their efforts. For example, they extracted metals from ores produced a number of inorganic acids and bases that later became commercially important and developed the techniques of fusion, calcination, solution, filtration, crystallization, sublimation, and, most importantly, distillation. During the Middle Ages, they began to try to systematize the results of their primitive experiments and their fragments of information in order to explain or predict chemical reactions between substances. Thns the idea of chemical elements and the first primitive forms of the chemical Periodic Table appeared. 

Significant work during this period was directed at developing a non-precious metal-based or base metal water gas shift catalyst (Figure 1). The initial activity, k , and the deactivation rate, kj, are determined from a fit of the measured conversion curve shown in Figure 1 after the first 5 to 10 hours. These kj and values for these catalysts are summarized in Table 1 with the Pt catalyst reported in Reference 2 included for comparison. 

Alternative methods are used where XRF fails, i.e., for elements below sodium in the periodic table, for volatile elements and precious metals not amenable to fusion, for liquids, and for some trace analyses. In the case of trace analysis (in ceramics <100pg per g), XRF meets the requirements for many elements even with a 5 1 flux/sample ratio, particularly for U, Th, Y, La, V, Rb, Cs, Ga, Ge, Ce, Nd, Pr, Sc, and Ni. 

While Pd prices have tended to retain a relative value of 30 % with respect to the price of Pt over the time period shown in Fig. 19.9, the relative prices of other precious metals with respect to Pt are more variable. Table 19.2 shows the costs of various precious metals with respect to Pt over the last 1-, 5-, and 10-year periods calculated from the data in Fig. 19.12 and prices for Rh over the same time period. 

---