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Hello everyone, today I want to tell you about a rare noble gas: xenon
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In the periodic table of chemical elements, xenon is located in the last group
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almost at the bottom.
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Like its buddy Neon, the heavier Xenon is also part of the noble gas branch.
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The chemical activity of which is very low, due to the lack of free electrons in the outer electron layer.
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To provide a simpler example, as a noble gas can be compared the lazy well-fed cat,
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who doesn't want to take anything, but also has nothing to give.
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Nevertheless, externally Xenon looks like colourless, odorless gas.
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To demonstrate the properties of which, i bought a vial of xenon
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wherein the gas is stored at reduced pressure, so that it is easier to conduct demonstrations with it.
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Like the other noble gases, while passing a high voltage through xenon,
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it glows with a beautiful blue color.
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For the glow, you need to create low pressure in the ampule
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that is approximately 100 times less than atmospheric and also to pass through the vial
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at high frequency voltage of about 3000V.
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This high voltage can be given by the generator of a plasma lamp,
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from the effect of which a glow discharge occurs in xenon.
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In other words, the gas starts to glow beautifully.
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The current here is insignificant. So my hand can easily play the role of a conductor here
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due to the human body having capacity like in an electrical capacitor.
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If the vial of xenon is put in liquid nitrogen,
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The gas inside will freeze,
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because the melting point of xenon is about -111
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degrees celsius. When you get the vial out of liquid
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nitrogen, you can then observe the solid
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xenon, which quickly melts and immediately
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evaporates, due to the very small difference
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between the boiling and melting points of this gas.
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[music]
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When chilled with the liquid nitrogen,
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The vial of xenon lights differently, than when it's at
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room temperature. It's clearly seen
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that the gas is ignited already even at the
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small distance from the wire
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as the first illumination is close in colour to yellow.
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After the gradual warm up of the vial,
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and increase of the pressure, the colour of the plasma
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becomes more blueish. However
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this is just us fooling around. In real
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life, xenon is used in much brighter lamps at which the gas is pressured at about 30 atmospheres.
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These lamps are just incredibly bright
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and are mostly used in cinema projectors. In recent times,
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these lamps are frequently replaced with LEDs,
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due to the low efficency and complexity of maintenance, besides the first heats up very strongly.
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Also, in recent years, xenon lamps were put into automobiles increasingly more often,
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though internally they are made a little bit differently.
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Xenon here is used only in order to ignite the arc plasma,
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after which the lamp heats up and inside of it
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sodium and scandium salts evaporate,
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those salts is what supports the further glow in this case.
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Xenon bulbs are much brighter than incandescent bulbs,
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which often causes frustration for motorists due to it blinding them at night,
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being too bright.
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Additionally, all the digital cameras now use a xenon flash,
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because of the extremely bright glow of this gas at a high voltage discharge.
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Unfortunately, xenon does not like to engage in chemical reactions,
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so I can't show you experiments with it.
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I can say though that this gas reacts with fluorine
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and later on from the fluorides of xenon you can obtain its oxide and other compounds.
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However, of all the noble gases, xenon is the most reactive due to the large atomic radius.
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Forgot to mention that the abundance of xenon in the earth's atmosphere is about 87 parts per billion,
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the theory says that this small amount is due to the fact that part of the xenon is stored in quartz rocks coupled with oxygen.
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Though on Jupiter there's a lot more xenon than here.
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Being on xenon bulbs, this element is now used for general anesthesia
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as it blocks the NMDA receptor, responsible for the regulation of synopses
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that is the transmission of nerve impulses from the brain cell to another.
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Also, the inhalation of this gas during exercise
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promotes better muscle grow and more effective training.
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From that, xenon has been added to the least of doping substances.
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Another interesting application of xenon is in the space ion engines
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along with cesium because of the large atomic radius.
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Xenon can be ionised easily and quickly evaporated,
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thus maintaining stable operation of the ion engine.
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Such engines were placed on the space craft ''Deep Space''
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that was launched to conduct asteroid research,
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as well as the ''Smart 1'' satellite.
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In the end, we can say that xenon is fairly rare, but also a very useful gas.
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Now you have learned a little bit of the other elements.
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