字幕表 動画を再生する 英語字幕をプリント Hello everyone, today I want to tell you about a rare noble gas: xenon In the periodic table of chemical elements, xenon is located in the last group almost at the bottom. Like its buddy Neon, the heavier Xenon is also part of the noble gas branch. The chemical activity of which is very low, due to the lack of free electrons in the outer electron layer. To provide a simpler example, as a noble gas can be compared the lazy well-fed cat, who doesn't want to take anything, but also has nothing to give. Nevertheless, externally Xenon looks like colourless, odorless gas. To demonstrate the properties of which, i bought a vial of xenon wherein the gas is stored at reduced pressure, so that it is easier to conduct demonstrations with it. Like the other noble gases, while passing a high voltage through xenon, it glows with a beautiful blue color. For the glow, you need to create low pressure in the ampule that is approximately 100 times less than atmospheric and also to pass through the vial at high frequency voltage of about 3000V. This high voltage can be given by the generator of a plasma lamp, from the effect of which a glow discharge occurs in xenon. In other words, the gas starts to glow beautifully. The current here is insignificant. So my hand can easily play the role of a conductor here due to the human body having capacity like in an electrical capacitor. If the vial of xenon is put in liquid nitrogen, The gas inside will freeze, because the melting point of xenon is about -111 degrees celsius. When you get the vial out of liquid nitrogen, you can then observe the solid xenon, which quickly melts and immediately evaporates, due to the very small difference between the boiling and melting points of this gas. [music] When chilled with the liquid nitrogen, The vial of xenon lights differently, than when it's at room temperature. It's clearly seen that the gas is ignited already even at the small distance from the wire as the first illumination is close in colour to yellow. After the gradual warm up of the vial, and increase of the pressure, the colour of the plasma becomes more blueish. However this is just us fooling around. In real life, xenon is used in much brighter lamps at which the gas is pressured at about 30 atmospheres. These lamps are just incredibly bright and are mostly used in cinema projectors. In recent times, these lamps are frequently replaced with LEDs, due to the low efficency and complexity of maintenance, besides the first heats up very strongly. Also, in recent years, xenon lamps were put into automobiles increasingly more often, though internally they are made a little bit differently. Xenon here is used only in order to ignite the arc plasma, after which the lamp heats up and inside of it sodium and scandium salts evaporate, those salts is what supports the further glow in this case. Xenon bulbs are much brighter than incandescent bulbs, which often causes frustration for motorists due to it blinding them at night, being too bright. Additionally, all the digital cameras now use a xenon flash, because of the extremely bright glow of this gas at a high voltage discharge. Unfortunately, xenon does not like to engage in chemical reactions, so I can't show you experiments with it. I can say though that this gas reacts with fluorine and later on from the fluorides of xenon you can obtain its oxide and other compounds. However, of all the noble gases, xenon is the most reactive due to the large atomic radius. Forgot to mention that the abundance of xenon in the earth's atmosphere is about 87 parts per billion, 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. Though on Jupiter there's a lot more xenon than here. Being on xenon bulbs, this element is now used for general anesthesia as it blocks the NMDA receptor, responsible for the regulation of synopses that is the transmission of nerve impulses from the brain cell to another. Also, the inhalation of this gas during exercise promotes better muscle grow and more effective training. From that, xenon has been added to the least of doping substances. Another interesting application of xenon is in the space ion engines along with cesium because of the large atomic radius. Xenon can be ionised easily and quickly evaporated, thus maintaining stable operation of the ion engine. Such engines were placed on the space craft ''Deep Space'' that was launched to conduct asteroid research, as well as the ''Smart 1'' satellite. In the end, we can say that xenon is fairly rare, but also a very useful gas. Now you have learned a little bit of the other elements. If you would like to support the continous production of science videos like this one, please support the channel on Patreon Link in the video description. Please like and subscribe to my channel to see many more of new and interesting.
B2 中上級 米 キセノン - 地球上で最も明るいガス! (Xenon - THE BRIGHTEST Gas on Earth!) 35 0 李冠緯 に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語