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The lanthanide and actinide elements (the f-block) are called inner transition metals and are sometimes considered to be transition metals as well. They are lustrous metals with good electrical and thermal conductivity. Most (with the exception of group 11 and group 12) are hard and strong, and have high melting and boiling temperatures.
These elements are generally not considered part of any group. They are sometimes called inner transition metals because they provide a transition between the s-block and d-block in the 6th and 7th row (period), in the same way that the d-block transition metals provide a transitional bridge between the s-block and p-block in the 4th and 5th rows.
The s- and p-block elements, which fill their outer shells, are called main-group elements; the d-block elements (coloured blue below), which fill an inner shell, are called transition elements (or transition metals, since they are all metals). [61]
Noble metals – Variously-defined group of metals that are generally resistant to corrosion. Usually includes Ag, Au, and the platinum-group metals. Non-ferrous metals - Metals or alloys that do not contain iron in appreciable amounts. Platinum group – Ru, Rh, Pd, Os, Ir, Pt. Post-transition metals – The metals coming after the transition ...
In nuclear chemistry, the actinide concept (also known as actinide hypothesis) proposed that the actinides form a second inner transition series homologous to the lanthanides. Its origins stem from observation of lanthanide-like properties in transuranic elements in contrast to the distinct complex chemistry of previously known actinides.
Similar variation on the inner transition metals continues to exist in textbooks, although the correct positioning has been known since 1948 and was twice endorsed by IUPAC in 1988 (together with the 1–18 numbering) and 2021. Groups may also be identified using their topmost element, or have a specific name.
The s-block elements are primarily characterised by one main oxidation state, and the p-block elements, when they have multiple oxidation states, often have common oxidation states separated by two units. Main-group elements (with some of the lighter transition metals) are the most abundant elements on Earth, in the Solar System, and in the ...
In many sources "transition metal" and "inner transition metal" are used instead of "transition element" and "inner transition element", as those elements are all metals. The 2005 IUPAC Red Book excludes hydrogen from the main-group elements, but this exclusion is often not followed in practice, and the 2011 IUPAC Principles of Chemical ...