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The stability has in part been correlated to differences in volatility between the lanthanide metals. [78] In EuB 6 and YbB 6 the metals have an oxidation state of +2 whereas in the rest of the lanthanide hexaborides it is +3. This rationalises the differences in conductivity, the extra electrons in the Ln III hexaborides entering conduction bands.
The hexaborides of the lighter lanthanides (La – Sm) melt without decomposition, EuB 6 decomposes to boron and metal and the heavier lanthanides decompose to LnB 4 with exception of YbB 6 which decomposes forming YbB 12. The stability has in part been correlated to differences in volatility between the lanthanide metals. [34]
Like the lanthanides, all actinides are highly reactive with halogens and chalcogens; however, the actinides react more easily. Actinides, especially those with a small number of 5f-electrons, are prone to hybridization. This is explained by the similarity of the electron energies at the 5f, 7s and 6d shells. Most actinides exhibit a larger ...
Lanthanide and actinide aqua ions have higher solvation numbers (often 8 to 9), with the highest known being 11 for Ac 3+. The strength of the bonds between the metal ion and water molecules in the primary solvation shell increases with the electrical charge, z, on the metal ion and decreases as its ionic radius, r, increases. Aqua ions are ...
The lanthanide and actinide elements (the f-block) are called inner transition metals and are sometimes considered to be transition metals as well. Since they are metals, they are lustrous and have good electrical and thermal conductivity.
Furthermore, since only the first two lanthanides (Ce and Pr) can reach the oxidation state corresponding to the loss of all valence electrons (and Pr needs noble-gas matrix isolation conditions to do so), but the first five actinides can do it (Th, Pa, U, Np, and Pu, although only transiently for Pu), it would seem that the outer electrons of ...
During this period, 5f organometallic science has blossomed, and it is now apparent that the actinides have a rich, intricate, and highly informative organometallic chemistry. Intriguing parallels to and sharp differences from the d-block elements have emerged. Actinides can coordinate the organic active groups or bind to carbon by the covalent ...
Due to the effects of the lanthanide contraction, yttrium and lutetium are very similar in properties. Yttrium and lutetium have essentially the chemistry of the heavy lanthanides, but scandium shows several differences due to its small size. This is a similar pattern to those of the early transition metal groups, where the lightest element is ...