![]() As a result, elements in the same group often display similar properties and reactivity. ![]() The elements in each group have the same number of valence electrons. This behavior is in sharp contrast to that of the p-block elements, where the occurrence of two oxidation states separated by two electrons is common, which makes virtually all compounds of the p-block elements diamagnetic.ĭue to a small increase in successive ionization energies, most of the transition metals have multiple oxidation states separated by a single electron. The s-, p-, and d-block elements of the periodic table are arranged into 18 numbered columns, or groups. The occurrence of multiple oxidation states separated by a single electron causes many, if not most, compounds of the transition metals to be paramagnetic, with one to five unpaired electrons. Because of the slow but steady increase in ionization potentials across a row, high oxidation states become progressively less stable for the elements on the right side of the d block. These two elements make up the first row of the periodic table (Figure 9.7.2 9.7. The transition metals make use of the d-subshell, which can accommodate 10 electrons. Their electron configurations are 1 s 1 and 1 s 2, respectively with He, the n 1 shell is filled. This periodic table shows the valences of element groups. Manganese, for example, forms compounds in every oxidation state between −3 and +7. The shape of the periodic table mimics the filling of the subshells with electrons. The relatively small increase in successive ionization energies causes most of the transition metals to exhibit multiple oxidation states separated by a single electron. Thus all the first-row transition metals except Sc form stable compounds that contain the 2+ ion, and, due to the small difference between the second and third ionization energies for these elements, all except Zn also form stable compounds that contain the 3+ ion. This in turn results in extensive horizontal similarities in chemistry, which are most noticeable for the first-row transition metals and for the lanthanides and actinides. The similarity in ionization energies and the relatively small increase in successive ionization energies lead to the formation of metal ions with the same charge for many of the transition metals. Trends in Transition Metal Oxidation States As a result, the metals in the lower right corner of the d block are so unreactive that they are often called the “noble metals.” The electronegativity of the elements increases, and the hydration energies of the metal cations decrease in magnitude from left to right and from top to bottom of the d block. \): Some Trends in Properties of the Transition Metals.
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