Xenon
Xenon is a chemical element on the periodic table whose symbol is Xe and its atomic number is 54. Odorless, very heavy, colorless noble gas, xenon is present in the Earth's atmosphere only in trace amounts and was part of the first noble gas compound synthesized.
Main or particular characteristics
Xenon is a member of the eight valence elements called noble or inert gases. The word "inert" it is no longer used to describe this chemical series, since some zero-valence elements form compounds. In a tube filled with xenon gas, a blue glow is emitted when excited by an electric discharge. Metallic xenon has been obtained by applying pressures of several hundred kilobars. Xenon can also form clathrates with water when its atoms become trapped in a lattice of oxygen molecules.
Xenon has atomic number 54; that is, its nucleus contains 54 protons. Under standard conditions of pressure and temperature, pure xenon gas has a density of 5.894 kg/m3, about 4.5 times as dense as the Earth's atmosphere at sea level, 1.217 kg/m 3. As a liquid, xenon has a density of up to 3,100 g/mL, with the maximum density occurring at the triple point. Liquid xenon has high polarizability due to its large atomic volume and is therefore an excellent solvent. It can dissolve hydrocarbons, biological molecules, and even water. Under the same conditions, the density of solid xenon, 3.640 g/cm3, is greater than the average density of granite, 2.75 g/cm3. At high gigapascal pressures, xenon forms a metallic phase.
Solid xenon changes from face centered cubic (fcc) to hexagonal close packed (hcp) under pressure and begins to turn metallic at approximately 140 GPa, with no noticeable volume change in the hcp phase. It is all metallic at 155 GPa. When metallized, xenon appears sky blue because it absorbs red light and transmits other visible frequencies. This behavior is unusual for a metal and is explained by the relatively small width of the electron bands in that state.
(animated version)
Liquid or solid xenon nanoparticles can be formed at room temperature by implanting Xe+ ions into a solid matrix. Many solids have smaller lattice constants than the Xe solid. This results in compression of the implanted Xe to pressures that may be sufficient for its liquefaction or solidification.
Xenon is a member of the zero-valence elements called noble or inert gas. It is inert to most common chemical reactions (like combustion, for example) because the outer valence shell contains eight electrons. This produces a stable minimum energy configuration in which the outer electrons are tightly bound.
In a gas-filled tube, xenon emits a blue or lavender glow when excited by an electrical discharge. Xenon emits a band of emission lines spanning the visual spectrum, but the most intense lines occur in the region of blue light, producing the coloration.
History
Xenon (from the Greek ξενόν xenos meaning "strange") was discovered by William Ramsay and Morris Travers in 1898 in residues obtained from evaporate the components of liquid air.
Abundance and obtaining
It is found in trace amounts in the Earth's atmosphere, appearing at one part in twenty million. The element is obtained commercially by extracting residues from liquefied air. This noble gas is found naturally in gases emitted from some natural springs. The isotopes Xe-133 and Xe-135 are synthesized by neutron irradiation in air-cooled nuclear reactors.
Compounds
Before 1962, xenon and the other noble gases were considered chemically inert and incapable of forming compounds. Since then it has been proven that xenon, along with other noble gases, does form compounds. Some of the xenon compounds are: difluoro, hexafluoro, sodium perxenate, terafluor, xenon deuteride, and xenon hydroxide. Xenon trioxide, a highly explosive compound, has also been obtained. At least 80 xenon compounds are known in which it bonds with fluorine or oxygen. Most of these compounds are colorless.
Isotopes
In nature, xenon occurs in seven stable and two slightly radioactive isotopes. In addition to these stable forms, 20 more unstable isotopes have been studied. Xe-129 is produced by beta emission from I-129 (half-life: 16 million years); isotopes Xe-131, Xe-132, Xe-134 and Xe-136 are fission products of both U-238 and Pu-244.
Since xenon is a tracer with two parent isotopes, the measurement of xenon isotopes in meteorites turns out to be a powerful tool for studying the formation of the Solar System. The I-Xe method of radiometric dating makes it possible to calculate the time elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula. Xenon isotopes are also useful for understanding terrestrial differentiation. The excess Xe-129 found in carbon dioxide gasses in New Mexico is believed to be due to the decay of mantle-derived gases shortly after Earth's formation.
Applications
The main and most famous use of this gas is in the manufacture of light-emitting devices such as bactericidal lamps, electronic tubes, strobe lamps, and photographic flashes, as well as in lamps used to excite ruby lasers, thus generating form coherent light. Other uses are:
- As anesthetic in general anesthesia.
- In nuclear installations, it is used in bubble chambers, probes, and in other areas where the high molecular weight is a desirable quality.
- Perxenatos are used as oxidant agents in analytical chemistry.
- The Xe-133 isotope is used as a radioisotope.
- It is used in car headlights.
- Xenon lamps are widely used in film projectors.
- Ionic propulsion gas for satellites.
- In printers or photocopiers, for the ink to seal on the paper sheet.
Use in medicine
Xenon was first identified as an anesthetic in 1951. Its use is not approved in the United States, and it is unlikely to see widespread use because it is a rare gas that cannot be manufactured and must extracted from the air, becoming a rather expensive medicine. Despite this, xenon presents characteristics close to those of a virtually ideal anesthetic gas, which can be used in critical situations.
It is highly insoluble in blood and body tissues, which allows rapid induction and subsequent recovery. It is powerful enough to generate surgical anesthesia when administered with 30% oxygen. It has minimal adverse effects.
Anesthesia
Xenon has been used as a general anesthetic, but is more expensive than other conventional anesthetics.
Xenon interacts with many different receptors and ion channels, and like many theoretically multimodal inhalation anesthetics, these interactions are likely complementary. Xenon is a high affinity glycine site NMDA receptor antagonist. However, xenon differs from other NMDA receptor antagonists in that it is non-neurotoxic and inhibits the neurotoxicity of ketamine and nitrous oxide (N2O), while actually producing neuroprotective effects. Unlike ketamine and nitrous oxide, xenon does not stimulate dopamine flow in the nucleus accumbens.
Like nitrous oxide and cyclopropane, xenon activates the TREK-1 two-pore potassium channel. A related channel TASK-3 also implicated in the actions of inhalation anesthetics is insensitive to xenon. Xenon inhibits α4β2 nicotinic acetylcholine receptors which contribute to spinal-managed analgesia. Xenon is an effective inhibitor of plasma membrane Ca2+ ATPase. Xenon inhibits Ca2+ ATPase by binding to a hydrophobic pore within the enzyme and preventing the enzyme from adopting active schemata.
Xenon is a competitive inhibitor of the serotonin 5-HT3 receptor. Although it is not an anesthetic or antinociceptive, it reduces nausea and vomiting arising from anesthesia.
Xenon has a minimum alveolar concentration (MAC) of 72% by age 40, making it 44% more potent than N2O as an anesthetic. Therefore it can be used in conjunction with oxygen in concentrations that have a low risk of hypoxia. Unlike nitrous oxide, xenon is not a greenhouse gas and is considered environmentally friendly. Although it is recycled in modern systems, xenon released into the atmosphere only returns to its original source, with no environmental impact.
Neuroprotective
Xenon induces robust cardioprotection and neuroprotection through a variety of mechanisms. Through its influence on Ca2+, K+, KATPHIF, and NMDA antagonism, xenon is neuroprotective when administered before, during, and after episodes. ischemic. Xenon is a high affinity antagonist at the glycine site of the NMDA receptor. Xenon is cardioprotective under ischemia-reperfusion conditions by inducing a non-ischemic pharmacological preconditioning. Xenon is cardioprotective by activating PKC-epsilon and downstream p38-MAPK. Xenon mimics neuronal ischemic preconditioning by activating ATP-sensitive potassium channels. Xenon allosterically reduces ATP-mediated inhibition of channel activation independent of the sulfonylurea receptor 1 subunit, increasing the time and frequency of the KATP channel open.
Sports doping
Inhalation of a mixture of xenon and oxygen activates the production of the transcription factor HIF-1-alpha, which can lead to increased production of erythropoietin. The latter hormone is known to increase red blood cell production and athletic performance. Doping with xenon inhalation has reportedly been used in Russia since 2004 and perhaps earlier. On August 31, 2014, the World Anti-Doping Agency (WADA) added xenon (and argon) to the list of prohibited substances and methods, although reliable doping tests for these gases have not yet been developed. the effects of xenon on erythropoietin production in humans have been demonstrated.
Images
The Gamma emission from the radioisotope 133Xe xenon can be used to image the heart, lungs, and brain, for example, by means of single photon emission computed tomography. 133Xe has also been used to measure blood flow.
Xenon, particularly hyperpolarized 129Xe, is a useful contrast agent for magnetic resonance imaging (MRI). In the gas phase, it can image the cavities of a porous sample, lung alveoli, or the flow of gases within the lungs. Because xenon is soluble in both water and hydrophobic solvents, it can image a variety of tissues live soft.
Xenon-129 is currently used as a visualization agent in MRIs. When a patient inhales hyperpolarized xenon-129, ventilation and gas exchange in the lungs can be visualized and quantified. Unlike xenon-133, xenon-129 is non-ionizing and is safe to inhale with no adverse effects.
Surgery
The excimer chloride xenon laser has certain dermatological uses.
Precautions
Gas can be safely stored in conventional sealed glass containers at ambient temperature and pressure. Xenon is non-toxic, but several of its compounds are highly so due to their strong oxidizing properties.
This gas produces the opposite effect to helium and when inhaled it makes your voice deeper.
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