8/5/2023 0 Comments Xe electron configurationThe electrons may be listed, as shown here, in the order of increasing major quantum number. The total of the superscripted numbers should equal the atomic number of bismuth, 83. Note that 3 is the lowest possible value that n may have for a d orbital, and that 4 is the lowest possible value of n for an f orbital. SOLUTION We can do this by simply moving across the periodic table one row at a time and writing the occupancies of the orbital corresponding to each row (refer to Figure 6.29). Write the electron configuration for the element bismuth, atomic number 83. What family of elements is characterized by having an ns 2 np 2 outer-electron configuration? Answer: Group 4A Recall also that the 1 s subshell is the first s subshell, the 2 p is the first p subshell, the 3 d is the first d subshell, and the 4 f is the first f subshell.įIGURE 6.29 Block diagram of the periodic table showing the groupings of the elements according to the type of orbital being filled with electrons. Recall that the numbers 2, 6, 10, and 14 are precisely the number of electrons that can fill the s, p, d, and f subshells, respectively. These elements are often referred to as the f-block metals because they are the ones in which the f orbitals are being filled. Below the main portion of the table are two rows that contain fourteen columns. These are the elements in which the d orbitals are being filled. In the middle of the table is a block of ten columns that contains the transition metals. The s block and the p block of the periodic table contain the representative (or main-group) elements. These are the elements in which the outermost p orbitals are being filled. These elements, known as the alkali metals (group 1A) and alkaline earth metals (group 2A), are those in which the outer-shell s orbitals are being filled. Notice that the elements can be grouped in terms of the type of orbital into which the electrons are placed. The pattern is summarized in Figure 6.29. You can easily write the electron configuration of an element based on its location in the periodic table. For this reason we will emphasize that the periodic table is your best guide to the order in which orbitals are filled. Likewise, the 4 d orbitals don't begin to fill until the fifth row of the table, and the 4 f orbitals don't begin filling until the sixth row.Īll of these observations are evident in the structure of the periodic table. As noted earlier, the remaining orbitals of the third shell, the 3 d orbitals, do not begin to fill until the fourth row of the periodic table (and after the 4 s orbital is filled). For example, the third row has eight elements, which corresponds to filling the 3 s and 3 p orbitals. Some of the numbers repeat because we reach the end of a row of the periodic table before a shell completely fills. The first row has two elements, the second and third rows have eight elements, the fourth and fifth rows have 18 elements, and the sixth row has 32 elements (including the lanthanide metals). We see that the beautiful structure of the periodic table reflects this orbital structure. Because each orbital can hold two electrons, each shell can accommodate up to 2 n 2 electrons: 2, 8, 18, or 32. We see that the 2A elements all have ns 2 outer configurations while the 3A elements have ns 2 np 1 configurations.Įarlier, in Table 6.2, we saw that the total number of orbitals in each shell is equal to n 2: 1, 4, 9, or 16. For example, the electron configurations for the elements in groups 2A and 3A are given in Table 6.4. The periodic table is structured so that elements with the same pattern of outer-shell (valence) electron configuration are arranged in columns. We have seen that the electron configurations of elements are related to their location in the periodic table. Our rather brief survey of electron configurations of the elements has taken us through the periodic table. Chapter 9 Electron Configurations and the Periodic Table
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |