Group 3 scandium

We have not discussed in detail the transition metals of Groups Ilia, IVa, Va, or Vila. The first of these four, the scandium group, contains the rare and invariably tripositive metals, scandium (Z = 21), yttrium (Z = 39), and lanthanum (Z = 57) these elements are best considered with the rare earths and will not be taken up in this text. 

The ground state configuration of lanthanides, 4/" l5d 6s2 or 4/"6s2 does not determine the chemical behaviour of these elements. In forming Ln3+ ions, an / electron is removed. Lanthanides differ from transition elements in that 4/ orbitals are shielded and are not available for reactions. Thus lanthanides resemble more closely alkaline earths and the scandium group than transition elements in their chemistry. 

Scandium Group 3 element, symbol Sc, Z = 21, Ar = 44.9559. Technically, Scandium is a member of the first row transition metal series, but its chemistry is principally that of the Sd+ ion which has no d electrons. 

PANI Composites with Oxides of the Scandium Group of Transition Metals... 

Scandium group elements as well as the lanthanides form allyl complexes in which the central atom has H- 3 oxidation state, while the actinides give compounds possessing + 4 oxidation states (Table 7.14). These complexes are formed by reactions of metal halides with allyl compounds of magnesium, lithium, tin, etc. " " ... 

Meanwhile, as mentioned above, the metallurgist Habashi has proposed a periodic table in which the element aluminum k moved to the top of the scandium group. Moving to chemists, Rayner Canham has published an Inorganic Chemist s Table (see figure 10.12), in which he highlights a number of unusual relationships, several of which have been reviewed in thk chapter. One particularly unusual feature of his table is the inclusion of the ions CN and NH/ because of their similarities to certain elements. 

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