7/4/2023 0 Comments Periodic table k 3dSimilarity of valence shell electron configuration implies that we can determine the electron configuration of an atom solely by its position on the periodic table. However, many similarities do exist in these blocks, so a similarity in chemical properties is expected. In the d and f blocks, because there are exceptions to the order of filling of subshells with electrons, similar valence shells are not absolute in these blocks. This is strictly true for all elements in the s and p blocks. Elements in each column have the same valence shell electron configurations, and the elements have some similar chemical properties. The same concept applies to the other columns of the periodic table. The organization of electrons in atoms explains not only the shape of the periodic table but also the fact that elements in the same column of the periodic table have similar chemistry. Because much of the chemistry of an element is influenced by valence electrons, we would expect that these elements would have similar chemistry - and they do. They all have a similar electron configuration in their valence shells: a single s electron. Their electron configurations (abbreviated for the larger atoms) are as follows, with the valence shell electron configuration highlighted: Table 8.4 Electron Configurations of Elements in the First Column of the Periodic Table Element For example, take the elements in the first column of the periodic table: H, Li, Na, K, Rb, and Cs. If we look at just the valence shell’s electron configuration, we find that in each column, the valence shell’s electron configuration is the same. (The inner electrons are called core electrons.) The valence electrons largely control the chemistry of an atom. The electrons in the highest-numbered shell, plus any electrons in the last unfilled subshell, are called valence electrons the highest-numbered shell is called the valence shell. Instead of filling the 3 d subshell next, electrons go into the 4 s subshell, which consists of K and Ca (Figure 8.18 “The 4 s Subshell”).įigure 8.20 “Blocks on the Periodic Table.” The periodic table is separated into blocks depending on which subshell is being filled for the atoms that belong in that section. Figure 8.17 “The 3 p Subshell.” Next, the 3 p subshell is filled with electrons. Next, the 3 p subshell is filled with the next six elements (Figure 8.17 “The 3 p Subshell”). Figure 8.16 “The 3 s Subshell.” Now the 3 s subshell is being occupied. The elements when this subshell is being filled, Na and Mg, are back on the left side of the periodic table (Figure 8.16 “The 3 s Subshell”). The next subshell to be filled is the 3 s subshell. Figure 8.15 “The 2 p Subshell.” For B through Ne, the 2 p subshell is being occupied. On the right side of the periodic table, these six elements (B through Ne) are grouped together (Figure 8.15 “The 2 p Subshell”). Figure 8.14 “The 2 s Subshell.” In Li and Be, the 2 s subshell is being filled.įor the next six elements, the 2 p subshell is being occupied with electrons. Figure 8.14 “The 2 s Subshell” shows that these two elements are adjacent on the periodic table. The next two electrons, for Li and Be, would go into the 2 s subshell. Figure 8.13 “The 1 s Subshell.” H and He represent the filling of the 1 s subshell. These two elements make up the first row of the periodic table (see Figure 8.13 “The 1 s Subshell”). Their electron configurations are 1 s 1 and 1 s 2, respectively with He, the n = 1 shell is filled. Why does the periodic table have the structure it does? The answer is rather simple, if you understand electron configurations: the shape of the periodic table mimics the filling of the subshells with electrons. Figure 8.12 “The Periodic Table.” View an accessible periodic table online. A periodic table is shown in Figure 8.12 “The Periodic Table.” The elements are listed by atomic number (the number of protons in the nucleus), and elements with similar chemical properties are grouped together in columns. In Chapter 3 “Atoms, Molecules, and Ions”, we introduced the periodic table as a tool for organizing the known chemical elements.
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