First ionization energy transition elements

The first ionization energies of the elements are plotted in Figure 1.4. There is a characteristic pattern of the values for the elements Li to Ne which is repeated for the elements Na to Ar, and which is repeated yet again for the elements K, Ca and A1 to Kr (the s- and p-block elements of the fourth period). In the latter case, the pattern is interrupted by the values for the 10 transition elements of the d-block. The fourth period pattern is repeated by the fifth period elements, and there is an additional... 

The first ionization energies of the main group and transition metals are listed in Table 14.1. The first two series do not diflFer significantly from each other—sometimes an element of one series is higher, sometimes the other. Beginning with cesium the third series has a noticeably lower ionization energy as we might expect on the basis of... 

Figure 22.3 Horizontal trends in key atomic properties of the Period 4 elements. The atomic radius (A), electronegativity (B), and first ionization energy (C) of the elements in Period 4 are shown as posts of different heights, with darker shades for the transition series. The transition elements exhibit smaller, less regular changes for these properties than do the main-group elements.

The block of elements between Group 2 and Group 13 of the Periodic T able are known as the transition eiements or d-biock eiements (Sc to Zn and the elements below them). The eiements of the first transition series are those elements that have partly filled d orbitals in any of their common oxidation states, which are the block of elements headed by Ti to Cu. Here, we will look mainly at the properties of the first transition series Ti, V, Cr, Mn, Fe, Co, Ni and Cu. These elements are typical metals and are often referred to as the transition metals. They have very similar physical properties. The changes in the atomic radii and first ionization energies across the first transition series are small, because each increase in nuclear charge is well shielded by the inner 3d electrons and only a small increased attraction is noticed by the outer electrons in the 4s subshell. See Box 12.7. 

First ionization energy Larger than caicium Smaller than transition elements... 

Within a group, the first ionization energy decreases downward, with some exceptions. The transition elements do not conform folly to these patterns. We shall, therefore, content ourselves with the broad generalization that the first ionization energy increases across a period and decreases down a group. 

Ionization energy. Plot the first ionization energy y axis) versus atomic number (x axis) for period 2 and for the transition elements Sc to Cu on the same scale. See Table 7.7, page 114, for data. What conclusion(s) could you draw from these graphs ... 

Ionization energies are fairly constant across the first transition series. Values of the first ionization energies are about the same as for the group 2 metals. Standard electrode potentials gradually increase in value across the series. With the exception of the oxidation of Cu to Cu, however, all these elements are more readily oxidized than hydrogen. This means these metals reduce H (aq) to H2(g). Additional comments on electrode potentials, some supported by electrode potential diagrams, are found throughout the chapter. 

Calculate the sum of the first two ionization energies for the first-series transition elements, and account for the general trend. 

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