![]() Other authors focusing on superheavy elements since clarified that the "15th entry of the f-block represents the first slot of the d-block which is left vacant to indicate the place of the f-block inserts", which would imply that this form still has Lu and Lr (the 15th entries in question) as d-block elements under Sc and Y. In fact, relativistic quantum-mechanical calculations of Lu and Lr compounds found no valence f-orbitals in either element. While the 2021 IUPAC report noted that 15-element-wide f-blocks are supported by some practitioners of a specialised branch of relativistic quantum mechanics focusing on the properties of superheavy elements, the project's opinion was that such interest-dependent concerns should not have any bearing on how the periodic table is presented to "the general chemical and scientific community". The spaces below yttrium are sometimes left blank as a third option, but there is confusion in the literature on whether this format implies that group 3 contains only scandium and yttrium, or if it also contains all the lanthanides and actinides either way, this format contradicts quantum physics by creating a 15-element-wide f-block when only 14 electrons can fit in an f-subshell. Many textbooks however show group 3 as containing scandium, yttrium, lanthanum, and actinium, a format based on historically wrongly measured electron configurations: Lev Landau and Evgeny Lifshitz already considered it to be "incorrect" in 1948, but the issue was brought to a wide debate only in 1982 by William B. It was supported by IUPAC in a 1988 report and reaffirmed in 2021. Physical, chemical, and electronic evidence overwhelmingly shows that the correct elements in group 3 are scandium, yttrium, lutetium, and lawrencium: this is the classification adopted by most chemists and physicists who have considered the matter. Some authors attempt to compromise between the two formats by leaving the spaces below yttrium blank, but this contradicts quantum mechanics as it results in an f-block that is 15 elements wide rather than 14 (the maximum occupancy of an f-subshell). This version of group 3 is still commonly found in textbooks, but most authors focusing on the subject are against it. Historically, sometimes lanthanum (La) and actinium (Ac) were included in the group instead of lutetium and lawrencium, because the electron configurations of many of the rare earths were initially measured wrongly. None of the group 3 elements have any biological role. Lawrencium is strongly radioactive: it does not occur naturally and must be produced by artificial synthesis, but its observed and theoretically predicted properties are consistent with it being a heavier homologue of lutetium. The first three of them occur naturally, and especially yttrium and lutetium are almost invariably associated with the lanthanides due to their similar chemistry. They quickly tarnish in air and react with water, though their reactivity is masked by the formation of an oxide layer. This is a similar pattern to those of the early transition metal groups, where the lightest element is distinct from the very similar next two.Īll the group 3 elements are rather soft, silvery-white metals, although their hardness increases with atomic number. Yttrium and lutetium have essentially the chemistry of the heavy lanthanides, but scandium shows several differences due to its small size. Due to the effects of the lanthanide contraction, yttrium and lutetium are very similar in properties. The chemistry of the group 3 elements is typical for early transition metals: they all essentially have only the group oxidation state of +3 as a major one, and like the preceding main-group metals are quite electropositive and have a less rich coordination chemistry. The group is also called the scandium group or scandium family after its lightest member. It contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr). This group is closely related to the rare-earth elements. Group 3 is the first group of transition metals in the periodic table.
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