Elements of group 3

Group 3 is the first group of transition metals in the periodic table. This group is closely related to the rare earth elements. Although there is some controversy as to the composition and location of this group, scholars generally agree that this group contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and Laurentium (Lr).). The group is also called the scandium group or scandium family after its lightest member. This group is the first of the transition metals.

The chemistry of the group 3 elements is typical of the early transition metals: they all have essentially only the +3 oxidation state as their parent, and like the preceding main group metals are quite electropositive and have a less rich coordination chemistry. They have a great tendency to oxidize and are very reactive. Due to the contraction effects of the lanthanides, yttrium and lutetium have very similar properties. Yttrium and lutetium essentially have heavy lanthanide chemistry, but scandium shows several differences due to its small size. This is a pattern similar to that of the early transition metal groups, in which the lightest element is distinguished from the next two, very similar ones.

All group 3 elements are fairly soft, silvery-white metals, although their hardness increases with atomic number. They cloud rapidly in air and react with water, although their reactivity is masked by the formation of an oxide layer. The first three are found in nature, and especially yttrium and lutetium are almost always associated with the lanthanides due to their similar chemistry. 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. None of them have any biological function.

Historically, lanthanum (La) and actinium (Ac) were sometimes included in the group instead of lutetium and actinium, and this option is still commonly found in textbooks. Some compromises between the two main options have been proposed and used, involving the reduction of the group to scandium and yttrium only, or the inclusion of the 30 lanthanides and actinides in the group as well.

History

Discoveries of the elements

The discovery of the group 3 elements is inextricably linked to that of the rare earths, with which they are universally associated in nature. In 1787, part-time Swedish chemist Carl Axel Arrhenius found a heavy black rock near the Swedish town of Ytterby, Sweden (part of the Stockholm Archipelago). Thinking it to be an unknown mineral containing the newly discovered element tungsten, he found it. he named ytterbite. Finnish scientist Johan Gadolin identified a new oxide or "earth" in Arrhenius's sample in 1789, and published his full analysis in 1794; in 1797, the new oxide was named yttria. In the decades after the French scientist Antoine Lavoisier developed the first definition modern chemical element, it was believed that earths could be reduced to their elements, which meant that the discovery of a new earth was equivalent to the discovery of the element it contained, which in this case would have been yttrium. Until the early 1920s, the chemical symbol "Yt" for the element, after which "Y" it came into common use. Yttrium metal, though impure, was first prepared in 1828 when Friedrich Wöhler heated [[yttrium(III) chloride] anhydrous] with potassium to form yttrium metal and potassium chloride. In fact, Gadolin's yttria turned out to be a mixture of many metal oxides, which started the story of the discovery of rare earths.

In 1869, Russian chemist Dmitri Mendeleev published his periodic table, which had an empty space for an element above yttrium. Mendeleev made several predictions about this hypothetical element, which he named eka-boron. By then, Gadolin's Yttria had already been divided several times; first by the Swedish chemist Carl Gustaf Mosander, who in 1843 had split two more lands which he called terbia and erbia (splitting the name Ytterby just as he had split the yttria); and then in 1878 when the Swiss chemist Jean Charles Galissard de Marignac divided the terbia and the erbia in turn into more lands. Among these was ytterbia (a component of ancient erbia), which the Swedish chemist Lars Fredrik Nilson successfully split in 1879 to reveal another new element. He called it scandium, from the Latin Scandia meaning means "Scandinavia". Nilson was apparently unaware of Mendeleev's prediction, but Per Teodor Cleve recognized the correspondence and notified Mendeleev. Chemical experiments on scandium proved that the elements predicted by Mendeleev's Suggestions were correct; together with the discovery and characterization of gallium and germanium, this demonstrated the correctness of the entire periodic table and periodic law. Metallic scandium was first produced in 1937 by electrolysis of a eutectic mixture, at 700-800° C, potassium, lithium, and scandium chloride. Scandium exists in the same minerals from which yttrium had been discovered, but it is much rarer and had probably eluded discovery for this reason.

The remaining component of Marignac ytterbia also turned out to be a compound. In 1907, French scientist Georges Urbain, Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James independently discovered a new element within ytterbia. Welsbach proposed the name cassiopeium for the new element of it (after Cassiopeia), while Urbain chose the name lutecium (from the Latin Lutetia, for Paris). The dispute over priority of discovery is documented in two articles in which Urbain and von Welsbach accuse each other of publishing results influenced by each other's published research. In 1909, the Atomic Mass Commission, responsible for the attribution of the names of the new elements, gave priority to Urbain and adopted their names as official. An obvious problem with this decision was that Urbain was one of four members of the commission. In 1949, the spelling of element 71 was changed to lutetium. Later work related to Urbain's attempts to further split his lutetium they revealed, however, that it contained only traces of the new element 71, and that only von Welsbach's Cassiopaean was pure element 71. For this reason, many German scientists continued to use the name Cassiopeia for the element until the 1950s. Ironically, Charles James, who had modestly kept out of the priority discussion, worked at a much larger scale than the others, and certainly possessed the largest supply of lutetium at the time. Lutetium was the last of the stable rare earths to be discovered. Over a century of research had split Gadolin's original yttrium into yttrium, scandium, lutetium, and seven other new elements.

Lutetium is the only element in the group that does not occur naturally. It was first synthesized by Albert Ghiorso and his team on February 14, 1961, at the Lawrence Radiation Laboratory (now called the Lawrence Berkeley National Laboratory) at the University of California in Berkeley, California, United States. The first atoms of lawrencium were produced by bombarding a three-milligram target made up of three isotopes of the element californium with boron-10 and boron-11 core of the Heavy Linear Ion Accelerator (HILAC). The nuclide ²⁵⁷103 was initially reported, but was later reassigned to ²⁵⁸103. The University of California team suggested the name lawrencium (after Ernest O. Lawrence, the inventor of the cyclotron particle accelerator) and the symbol "Lw", for the new item, however "Lw" it was not adopted, and instead the official designation "Lr" was accepted. Nuclear physicists in Dubna, Soviet Union (now Russia), reported in 1967 that they had been unable to confirm American scientists' data regarding ²⁵⁷103. Two years earlier, the Dubna team had reported about ²⁵⁶103. In 1992, the IUPAC Transfer-fermium Working Group officially recognized element 103, and confirmed its name as lawrencium, with the symbol "Lr", and named the Dubna and Berkeley groups of nuclear physicists as co-discoverers of lawrencium.

Dispute over composition

Historically, the rare earth elements gave the periodic table a lot of trouble. In 1871, the Russian chemist Dmitri Mendeleev (inventor of the periodic table) attempted to place them in the same groups as other elements, but further investigation of the rare earths made it clear that they did not display the necessary valences for those elements. collocations to make sense. In 1902, the Czech chemist Bohuslav Brauner suggested that all rare earths belonged to one place on the periodic table: he called this the 'asteroid hypothesis', since right between Mars and Jupiter is an asteroid belt. instead of a planet, so under the yttrium would be all the lanthanides instead of a single element.

With measurements of the ground-state gas-phase electronic configuration of the elements, and their adoption as the basis for placement in the periodic table, the oldest form of group 3 containing scandium, yttrium, lanthanum, and actinium gained prominence in the 1940s. The ground state configurations of cesium, barium, and lanthanum are [Cs]6s¹, [Ba]6s², and [La]5d ¹6s². Lanthanum thus emerges with a 5d differentiation electron and, for this reason, was considered to be in group 3 as the first d-block member for period 6. A superficially consistent set of configurations was then observed. electrons for group 3: scandium [Sc]3d¹4s², yttrium [Y]4d¹5s², lanthanum [La]5d¹6s² and actinium [Ac]6d¹7s². Even in period 6, ytterbium was wrongly assigned an electron configuration [Yb]4f¹³5d¹6s² and lutetium [Lu] 4f¹⁴5d¹6s², which suggested that lutetium was the last element of the f block. This format results in block f falling between groups 3 and 4 which it divides from block d.

Elements

Like other groups of d-block elements, group 3 should contain 4 elements, but there is no consensus on which ones it should comprise.

• Accepted:

• Scande (21)
• Itrio (39)

• Discutidos:

• Lantano (57) or Lutecio (71)
• Actinio (89) or Lawrencio (103)

Features

Chemicals

Like other groups, members of this family show patterns in their electronic configurations, especially in the outermost shells, giving rise to trends in chemical behavior. Due to relativistic effects that become important for high atomic numbers, the lawrencium configuration has an irregular 7p occupancy instead of the expected 6d, but the regular configuration [Rn]5f¹⁴6d< sup>17s² turns out to have a low enough energy that it does not have or is expected to have a significant difference with the rest of the group.

Most of the chemistry has been observed only for the first three members of the group; Lawrencium's chemical properties are not well characterized, but what is known and predicted agrees with its position as the heavier homologue of lutetium. The remaining elements of the group (scandium, yttrium, lutetium) are quite electropositive. They are reactive metals, although this is not obvious due to the formation of a stable oxide layer that prevents further reactions. Metals burn easily to give oxides, which are white, high-fusing solids. They typically oxidize to the +3 oxidation state, where they form mostly ionic compounds and have mostly cationic aqueous chemistry. In this way they are similar to the lanthanides, although they do not involve the f orbitals that characterize the chemistry of the 4f lanthanide elements through ytterbium. The stable group 3 elements are therefore often grouped with the 4f elements in the so-called rare earths.

The stereotypical properties of the transition metals are mostly absent in this group, as they are in the heavier elements of groups 4 and 5: there is only one typical oxidation state and the coordination chemistry is not very rich (although high coordination numbers are common due to the large size of the M³⁺ ions). That being said, low oxidation state compounds can be prepared and some cyclopentadienyl chemistry is known. Thus, the chemistries of the group 3 elements are distinguished primarily by their atomic radii: yttrium and lutetium are very similar, but scandium stands out as the least basic and the best complexing agent, approaching aluminum in some properties. They naturally take their place along with the rare earths in a number of trivalent elements: yttrium acts as an intermediate rare earth between dysprosium and holmium in basicity; lutetium as less basic than the 4f elements and the least basic of the lanthanides; and scandium as a rare earth less basic than even lutetium. Scandium oxide is amphoteric; lutetium oxide is more basic (although it can be made to show some acidic properties with difficulty), and yttrium oxide is even more basic. Salts with strong acids of these metals are soluble, while those with weak acids (for example, fluorides, phosphates, oxalates) are poorly soluble or insoluble.

Physics

The trends of group 3 follow those of the other early d-block groups and reflect the addition of a filled f-shell in the nucleus passing from the fifth to sixth periods. For example, scandium and yttrium are soft metals. But due to lanthanide contraction, the expected increase in atomic radius from yttrium to lutetium is in fact more than canceled out; lutetium atoms are slightly smaller than yttrium atoms, but are heavier and have a higher nuclear charge. This makes the metal denser, and also harder because the removal of electrons from the atom to form metallic bonding it gets harder. All three metals have similar melting and boiling points. Very little is known about lawrencium, but calculations suggest that it follows the trend of its lighter congeners toward increased density.

Scandium, yttrium, and lutetium crystallize in the close-packed hexagonal structure at room temperature, and lawrencium is expected to do the same. The stable members of the group are known to change structure at high temperature. Compared to most metals, they are not very good conductors of heat and electricity due to the low number of electrons available for metallic bonding.

Properties

• Reactive
• They drive electricity