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In transition metals, there are greater horizontal similarities in the properties of the elements in a period in comparison to the periods in which the d orbitals are not involved. This is because in a transition series, the valence shell electronic configuration of the elements do not change.
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.
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.
Main-group elements (with some of the lighter transition metals) are the most abundant elements on Earth, in the Solar System, and in the universe. Group 12 elements are often considered to be transition metals; however, zinc (Zn), cadmium (Cd), and mercury (Hg) share some properties of both groups, and some scientists believe they should be ...
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences.
Iron shows the characteristic chemical properties of the transition metals, namely the ability to form variable oxidation states differing by steps of one and a very large coordination and organometallic chemistry: indeed, it was the discovery of an iron compound, ferrocene, that revolutionalized the latter field in the 1950s. [59]
The definition of a metal is taken to include: post-transition metals, i.e. aluminium, gallium, indium, thallium, tin, lead, and bismuth. metalloids, e.g. silicon, germanium, arsenic, antimony and tellurium. Homogeneous and heterogeneous solid solutions of metals, and interstitial compounds such as the carbides and nitrides are excluded under ...
In such cases, the electron transfer is termed intermolecular electron transfer. A famous example of an inner sphere ET process that proceeds via a transitory bridged intermediate is the reduction of [CoCl(NH 3) 5] 2+ by [Cr(H 2 O) 6] 2+. [5] [6] In this case, the chloride ligand is the bridging ligand that covalently connects the redox ...