Elements periodic trends

Other periodic trends which occur in the chemical properties of the elements and which are discussed in more detail throughout later chapters are ... 

In addition to the prediction of new elements and their probable properties, the periodic table has proved invaluable in suggesting fruitful lines of research in the preparation of new compounds. Indeed, this mode of thinking is now so ingrained in the minds of chemists that they rarely pause to reflect how extraordinarily difficult their task would be if periodic trends were unknown. It is the ability to anticipate the effect of changing an element or a group in a compound which enables work to be planned effectively, though the prudent chemist is always alert to the possibility of... 

The usefulness of the main-group elements in materials is related to their properties, which can be predicted from periodic trends. For example, an s-block element has a low ionization energy, which means that its outermost electrons can easily be lost. An s-block element is therefore likely to be a reactive metal with all the characteristics that the name metal implies (Table 1.4, Fig. 1.60). Because ionization energies are... 

The general structure of this chapter is the same as that of Chapter 14. We work systematically across the remainder of the main-group elements to highlight periodic trends, the production of the elements, and the properties and applications of the elements and their important compounds. 

Predict and explain periodic trends in the properties of the elements in Groups 15/V through 18/VIII. 

We begin this chapter by summarizing the major periodic trends exhibited by the t/block elements and their compounds. Then we describe some of the properties and key reactions of selected elements. The d-block metals form a wide variety of complexes and, in the second half of the chapter, we describe their structures and the two principal theories of their bonding. We end the chapter by examining the contribution of d-block elements to some important modern materials. 

The physical and chemical properties of the elements show regular periodic trends that can be explained using electron configurations and nuclear charges. We focus on the physical properties of the elements in this section. A preliminary discussion of the chemical properties of some of the elements appears in Section Other chemical properties are discussed after we introduce the principles of chemical bonding in Chapters 9 and 10. 

C20-0001. Predict which element of the following pairs will have the higher melting point and support your prediction using periodic trends (a) Cr or W (b) W or Os (c) Pd or Ag and (d) Y or Nb. 

C noting periodic trends in the properties of known elements that surrounded the blank spaces in the periodic table... 

New scientific methods (e.g. electrolysis) allowed the veteran elements to be joined stepwise by more and more unknown and unexpected substances that fulfilled the criteria for an element. In 1869, after many attempts to bring order into the growing chaos, Dimitri Mendeleev revealed a daring concept with his Periodic Table and its predictions. Each of the then known elements was assigned a place. The gaps represented elements that were not yet known. The discoveries of such elements proved that there was an order and system to the elements. This order explained much that was previously puzzling, for instance, the different atomic radii observed that same year by Julius Lothar Meyer, which seemed to follow a periodic trend. 

The computational bond-length variations in Table 4.53 exhibit the expected periodic trends. Most noticeably, third- and second-series elements for groups 4, 6, and 10 exhibit similar bond lengths, i.e., the post-lanthanide contraction with respect to the ordinary increase of atomic size with increasing Z. 

Figure 6.5 Periodic trends in the surface tension of selected liquid elements in periods 2-6 at their melting temperature [8].

Our goal in this chapter is to familiarize you with some properties of the elements, as well as the periodic trends that you can observe in these properties. You might want to review briefly the periodic trends we discussed in Chapter 8. We will also discuss coordination compounds and complex ions. Again— Practice, Practice, Practice. 

What do elements look like How do they behave Can periodic trends in the properties of elements be observed You cannot examine all of the elements on the periodic table because of limited availability, cost, and safety concerns. However, you can observe several of the representative elements, classify them, and compare their properties. The observation of the properties of elements is called descriptive chemistry. 

An element s tendency towards partitioning into solid phases is related to its fundamental atomic properties. These properties follow periodic trends, giving rise to the trends shown in Figure 11.5 for the oceanic residence times of the elements. In the broadest sense, these trends reflect the relative tendency of an element towards electrostatic versus covalent interactions. Chemists have devised various measures of this tendency, such as an element s electronegativity and its ionization potential. The latter is a predictor of electrostatic interactions and is defined as the ratio, z /r, where... 

Two chemists in attendance at the Karlsruhe were Julius Lothar Meyer (1830-1895) and Dmitri Mendeleev (1834-1907). These two independently developed the periodic law and constructed their own versions of the periodic table. Meyer based his table primarily on the physical properties of the elements. Meyer plotted atomic volume against the atomic mass and noticed the periodicity in volumes of the elements. Other physical properties also showed periodic trends. Figure 6.2 shows how the melting point of the first fifty-five elements rises and falls in a roughly periodic fashion as atomic number increases. Based on his analysis, Meyer published his periodic table in 1870. 

The periodic trend of a decrease in atomic radii across a period is readily seen in the Figure 6.4. Other properties related to atomic radii show a similar pattern. Knowing that the elements exhibit a general periodic trend allows us to predict unknown properties for elements and aided in the discovery of unknown elements. The periodic nature of the elements supported the development of the quantum theory. The elements show a periodic pattern in both their properties and electron configurations. The periodic trend in properties of the elements... 

R. J. Puddephatt and P. K. Monaghan, The Periodic Table of the Elements, 2nd edn., Oxford University Press, Oxford, 1986. A concise description of the structure of the Periodic Table and a discussion of periodic trends of many physical and chemical properties of the elements. 

Periodic trend The gradual change of any property in the elements across a period. 

Another interesting periodic trend is density. Osmium, Os (atomic number 76), has the greatest density of all elements, and, with some exceptions, the closer an element is to osmium in the periodic table, the greater its density. Use this trend to list the following elements in order of increasing density copper, Cu gold, Au platinum, Pt and silver, Ag ... 

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