India has offered to redo the periodic table
Chemists from India made a detailed study of the properties of lanthanum, lutetium, actinium and Lawrence. As a result, they came to the conclusion that all of the lanthanides (15 elements) and the actinides (15 items) should represent in the periodic table in a separate group below. However, in its most common form today, the option lanthanum and actinium are in the third group the main part of the table. A study published in the journal Physical Chemistry Chemical Physics.
Periodic table of chemical elements invented long ago, but scientists continue to argue about the most successful way of its image, even if you do not have in mind exotic options like spiral, polygonal, and multi-dimensional. For example, today you can find “short” versions of the chart with the main and side subgroups only in old textbooks, while the “long” version of the 18 columns became standard. One of the contentious situations is still the position of lanthanum and actinium. You can often meet the case where these elements are located in the third group under scandium and yttrium, that is, d-block, which is named after the unfilled valence electron orbitals.
However, approving the standards for chemical nomenclature international Union of pure and applied chemistry (IUPAC) recommends the cells under a blank yttrium, lanthanum and actinium to be placed at the beginning of the group of the lanthanides and actinides, respectively, that is, in the f-block.News
In the new work, chemists have placed the first and last elements of the actinides and lanthanides in clusters of 12 atoms of lead or tin. The void in the middle of these formations are large enough for such large atoms, and good research into such systems allows to determine the characteristics in the middle of the element with high accuracy. The result using the density functional theory, the authors were able to determine the chemical properties of lanthanum, actinium, lutetium, and Lawrence, as well as the parameters of their electronic shells. As a result, the chemists found similarities in the behavior of electrons in f-orbitals, from which the authors recommended to place them all in a single block outside the main part of the table, as in the IUPAC.
However, not all experts agreed with this verdict. “Given discovered in this article, the similarity of lanthanum, actinium, lutetium, and Lawrence that demonstrate the properties of transition metals from d-block, has now become difficult to choose the best method in order to reflect this information in the table says not participating in the work of the chemist .. .. Lawall University of California, Los Angeles, USA — Transfer of all four elements in the f-block is visually appealing but goes against the logic of the rest of the table, and contrary obtained in the same study data, all four substances exhibit characteristic elements of the d-block of properties in the compounds.”