Livermorio

livermorium is the name of the synthetic element of the periodic table whose symbol is Lv and its atomic number is 116.

It is named in honor of the Lawrence Livermore National Laboratory (Lawrence Livermore National Laboratory), in Livermore, California.

History

In 2000, researchers from the Lawrence Berkeley National Laboratory announced the creation of element 116, in an article published in a US journal called Physical Review Letters, explaining that they did so when they observed the α-decay of a atom with the highest atomic number. The following year they published their retraction after finding that they were unable to redo the experiment. In June 2002, the laboratory's director announced that the experiment's data had been falsified by its lead author Victor Ninov.

In June 2000, the Joint Institute for Nuclear Research, in the city of Dubna, conducted studies describing the α-decay of the isotope ²⁹²Uuh that occurred in the reaction Fusion of a 248 Cm nucleus when bombarded with 48 Ca ions accelerated by a cyclotron, 4 neutrons were obtained as a secondary product. It has a half-life of about 6 milliseconds (0.006 seconds). After this it has an α-decay in 288Fl (Flerovio) followed by two more consecutive ones in other atoms of lower atomic number to later have a spontaneous fission.

New experiments were done between late 2000 and early 2001, but they failed to create a new atom.

On May 2, 2001, the same institute reported the synthesis of a second atom in its fourth round of studies, and that the properties confirmed a region of "enhanced" stability, although they are credited of high quality and careful confirmation of these results is still pending due to the lack of studies, including an X-ray study that proves the connection between the reactions and offspring.

In October 2006 it was announced that bombarding californium-249 atoms with calcium-48 ions three times produced ununoctium (element 118), which subsequently decayed to ununhexium in times of milliseconds. Confirming this, the synthesis of element 116 will have been definitively demonstrated.

The reaction that the livermorium creates is:

96248Cm+2048Ca→ → 116292Lv+401n{displaystyle ,_{96}^{248}mathrm {Cm} +,_{20}{48mathrm {Ca} ,to ,_{116}^{292}mathrm {Lv} +4;_{0}^{1}{1}mathrm {n}{;

It decays in 47 milliseconds to a previously identified isotope of element 114, Fl.

116292Lv→ → 114288Fl+24He{displaystyle ,_{116}^{292}mathrm {Lv} to ,_{114}^{288}mathrm {Fl} ,+,_{2}{4}mathrm {He} ;}

Predicted properties

Aside from nuclear properties, no properties of livermorium or its compounds have been measured; this is due to its extremely limited and expensive production and the fact that it decays very quickly. The properties of the livermorium remain unknown and only predictions are available.

Nuclear stability and isotopes

The expected location of the island of stability is marked by the white circle. The sharp line is the beta stability line.

Livermorium lies in the vicinity of the island of stability centered on copernicium (element 112) and flerovium (element 114). Due to the expected high fission barrier, any nuclei within this island of stability decay exclusively by alpha emission and perhaps some electron capture and beta decay. While the known isotopes of livermorium do not actually have enough neutrons to be on the island of stability, they can be seen to approach the island, as the heavier isotopes are generally the longest-lived.

Superheavy elements are produced by nuclear fusion. These fusion reactions can be divided into "hot" and "cold", depending on the excitation energy of the compound nucleus produced. In hot fusion reactions, very light, high-energy projectiles are accelerated towards very heavy (actinide) targets, resulting in compound nuclei at high excitation energy (~40–50 MeV) that can fission or evaporate several (3 to 5) neutrons. In cold fusion reactions (using heavier projectiles, usually fourth period, and lighter targets, usually lead and bismuth), the fused nuclei produced have a relatively low excitation energy (~10–20 MeV), which decreases the probability that these products undergo fission reactions. As the fused nuclei cool to the ground state, they require the emission of just one or two neutrons. Hot fusion reactions tend to produce more neutron-rich products because actinides have the highest neutron-to-proton ratios of any element that can currently be produced in macroscopic quantities.

Important information about the properties of superheavy nuclei could be obtained by synthesizing more isotopes of livermorium, specifically those with a few more or fewer neutrons than known: ²⁸⁶Lv, ²⁸⁷ Lv, ²⁸⁸Lv, ²⁸⁹Lv, ²⁹⁴Lv and ²⁹⁵Lv. This is possible because there are many reasonably long-lived isotopes of curium that can be used to make a target. Light isotopes can be made by fusing curium-243 with calcium-48. They would undergo a chain of alpha decays, ending up with transactinide isotopes that are too light to produce by hot fusion and too heavy to produce by cold fusion.

The synthesis of the heavy isotopes ²⁹⁴Lv and ²⁹⁵Lv could be achieved by fusing the heavy isotope curium-250 with calcium-48. The cross section of this nuclear reaction would be about 1 picobarn, although it is not yet possible to produce ²⁵⁰Cm in the amounts needed for target fabrication. After a few alpha decays, these livermorium isotopes would reach nuclides on the beta stability line. Furthermore, electron capture may also become an important decay mode in this region, allowing affected nuclei to reach the center of the island. For example, ²⁹⁵Lv is predicted to decay alpha to ²⁹¹Fl, which would undergo successive electron capture to ²⁹¹Nh and then ²⁹¹Cn which is expected to lie in the middle of the island of stability and have a half-life of around 1200 years, providing the most likely hope of reaching the center of the island using current technology. One drawback is that the decay properties of superheavy nuclei so close to the beta stability line are largely unexplored.

Other possibilities for synthesizing nuclei on the island of stability include quasi-fission (partial melting followed by fission) of a massive nucleus. Such nuclei tend to fission, ejecting double magic number or nearly double magic fragments such as calcium-40, tin-132, lead-208 or bismuth-209. It has recently been shown that multi-nucleon transfer reactions in collisions of actinide nuclei (such as uranium and curium) could be used to synthesize the neutron-rich superheavy nuclei located in the island of stability, although the formation of the lighter elements nobelium or seaborgium is more favored. A final possibility to synthesize isotopes near the island is to use controlled nuclear explosion to create a neutron flux high enough to bypass the instability gaps at ^258–260Fm and at mass number 275 (atomic numbers 104 to 108), mimicking the r process in which actinides s e occurred for the first time in nature and closed the instability gap around radon. Some of these isotopes (notably ²⁹¹Cn and ²⁹³Cn) may have been synthesized in nature, but would have decayed too quickly. (with half-lives of only thousands of years) and to be produced in amounts too small (about 10⁻¹² the abundance of lead) to be detectable as primordial nuclides today outside of cosmic rays.

Physics and Atomics

On the periodic table, livermorium is a member of group 16, the chalcogens. It appears below oxygen, sulfur, selenium, tellurium, and polonium. Each chalcogen above has six electrons in its valence shell, forming a valence electron configuration of ns²np⁴. In the case of livermorium, the trend should continue and the valence electron configuration is predicted to be 7s²7p⁴; therefore, livermorium has some similarities with their lighter counterparts. Differences are likely to arise; a large contributing effect is spin-orbit (SO) interaction: the mutual interaction between electron motion and spin. It is especially strong for superheavy elements, because their electrons move much faster than in lighter atoms, at speeds comparable to the speed of light. Relative to livermorium atoms, it lowers the energy levels of electrons. 7s and 7p (by stabilizing the corresponding electrons), but two of the 7p electron energy levels are stabilized more than the other four. The stabilization of the 7s electrons is called the inert pair effect, and the &#34 effect;tear apart" the 7p subshell into more stabilized and less stabilized parts is called the division of the subshell. Computer chemists see division as a change of the second (azimuthal) quantum number l from 1 to ¹⁄₂ and ³⁄₂ for the more and less stabilized parts of subshell 7p, respectively: the 7p_1/2 subshell acts as a second inert pair, though not as inert as the 7s electrons, while the 7p_3/2 subshell can easily participate in the chemistry. For many theoretical purposes, the valence electron configuration may be represented to reflect the 7p subshell split as 7s2
7p2
1/27p2
3/2 .

The inert pair effects in livermorium should be even stronger than in polonium, and therefore the +2 oxidation state becomes more stable than the +4 state, which would be stabilized only by the stronger ligands. electronegative; this is reflected in the expected ionization energies of the livermorium, where there are large gaps between the second and third ionization energies (corresponding to the rupture of the non-reactive 7p_1/2 shell) and energies of fourth and fifth ionization. In fact, the 7s electrons are expected to be so inert that the +6 state will not be achievable. The melting point and boiling point of livermorium are expected to continue the downward trends of chalcogens; therefore livermorium should melt at a higher temperature than polonium, but boil at a lower temperature. It should also be denser than polonium (α-Lv: 12.9 g/cm³; α-Po: 9.2 g/cm³); like polonium, it must also form an α and β allotrope. The electron in a livermorium hydrogen-like atom (oxidized so that it has only one electron, Lv¹¹⁵⁺) is expected moves so fast that it has a mass 1.86 times that of a stationary electron, due to relativistic effects (relativistic quantum chemistry). For comparison, the figures for hydrogen-like polonium and tellurium are expected to be 1.26 and 1.080 respectively.

Chemicals

Livermorium is projected to be the fourth member of the 7p series of chemical elements and the heaviest member of group 16 in the periodic table, below polonium. Although it is the least theoretically studied of the 7p elements, its chemistry is expected to be quite similar to that of polonium. The oxidation state of the +6 group is known for all chalcogens except oxygen which cannot expand its octet. and it is one of the strongest oxidants among the chemical elements. Therefore, oxygen is limited to a maximum state of +2, exhibited in OF2 fluoride. The +4 state is known for sulfur, selenium, tellurium, and polonium, undergoing a change in stability from the reduction of sulfur(IV) and selenium(IV) to being the more stable state for tellurium(IV) to being oxidizing to polonium. (IV). This suggests decreasing stability for the higher oxidation states as the group goes down due to the increasing importance of relativistic effects, especially the inert pair effect. The most stable oxidation state of livermorium should be +2, with a rather unstable +4 state. The +2 state should be as easy to form as it is for beryllium and magnesium, and the +4 state should only be achieved with strongly electronegative ligands, such as livermorium(IV) fluoride (LvF₄). The +6 state should not exist at all due to the strong stabilization of the 7s electrons, making the livermorium's valence nucleus only have four electrons. The lighter chalcogens are also known to form a −2 state as oxide, sulfide, selenide, telluride, and polonide; due to the destabilization of the 7p_3/2 subshell of livermorium, the −2 state should be very unstable for livermorium, whose chemistry should essentially be purely cationic, although the larger energy splits of the subshell and spinor of livermorium compared to polonium should make Lv²⁻ slightly less unstable than expected.

Livermoran (LvH₂) is the heaviest chalcogen hydride and the heaviest homologue in water (the lightest are H₂S, H₂ Se, H₂Te, andPoH₂). Polane (polonium hydride) is a more covalent compound than most hydrides because polonium straddles the metal-metalloid boundary and has some non-metallic properties: it is intermediate between a hydrogen halide like chloride hydrogen (HCl) and a metal hydride such as stannane (SnH₄). The livermoran should continue this trend: it should be a hydride rather than a livermoride, but still a covalent molecular compound. Spin-orbit interactions are expected to make the Lv-H bond longer than expected only at from periodic trends, and that the H-Lv-H bond angle is larger than expected: it is theorized that this is because the unoccupied 8s orbitals are relatively low in energy and can hybridize with the valence 7p orbitals of the livermorium. This phenomenon, termed "supervalent hybridization", is not particularly rare in non-relativistic regions of the periodic table; for example, molecular calcium difluoride has 4s and 3d participation of the calcium atom. The heavier livermorium dihalides are predicted to be linear, but the lighter ones are predicted to be bent.

Applications

Due to its instability, such a short half-life and difficulty in obtaining it, there are currently no industrial, commercial or advertising applications for this very heavy element, so its application is relegated only to scientific research.

The definitive name of Livermorio

Ununhexio is a temporary IUPAC name. Some scientists at the Joint Institute for Nuclear Research proposed the name "Flyorovium" (Fl) - in honor of G. N. Flyorov, head of the group that synthesized elements 102 to 110. But there is no mention confirming this name for the element yet.

On December 8, 2011, the IUPAC Division of Inorganic Chemistry confirmed the name and symbol for this element along with the name and symbol for Ununquandium, now called Flerovium (Fl). The definitive name decided was Livermorio (Lv), in honor of the National Laboratory of the city of Livermore, California.