Helium

AJ
by Alan Juszczyk1 view·Updated May 7, 2020
Create your own

Audio TranscriptAuto-generated

  1. this presentation is about a noble gas.
  2. Cold helium 1,000,000,000 is the second, lightest and the second
  3. most abundant element in the observable universe and constitutes 24%
  4. off all matter.
  5. It is, however, present on our Onley in trace amounts,
  6. but it has many applications, and this used in various
  7. aspects of life, like medicine, industry and under Daymond.
  8. What will I talk about in this presentation?
  9. First, I'm going to tell you about how it was
  10. discovered. Then I'm going to talk about its properties and
  11. finally about its applications and also production.
  12. The discovery of helium began in 18 68 when, during
  13. a solar eclipse in India, French astronomer Pierre Yinsen observed
  14. a yellow line, this solar spectrum.
  15. That line, however, was assumed to represent sell you.
  16. Later that year, English astronomer Norman work here observed the
  17. same line in the spectrum and concluded that he detected
  18. an unknown element in conjunction with English chemist Edward Frankland.
  19. They named the element after Greek word for some Helios.
  20. For many years, healing was considered an element that occurs
  21. on the sound but does not occur on Earth until
  22. 18 81 when Italian scientist Luigi Palmieri detected helium when
  23. he analysed sublimation off a material during her recent eruption
  24. off Mount Vesuvius.
  25. Finally, in 18 95 Scottish chemists there, William Ramsay isolated
  26. helium from uranium, or for the first time.
  27. Now let's move on to properties.
  28. Helium is an inert, tasteless, odorless gas that hits one
  29. of the lowest still ability in water off gases.
  30. It is chemically UNWRA, active under all normal conditions and
  31. the second least reactive noble gas.
  32. After noon, those scientists were able to form some compounds
  33. of helium.
  34. Those compounds were unstable.
  35. Helium atom consists off two electrons surrounding can you Kias
  36. that contains two products and usually tuna chunks.
  37. However, it can have upto eight neutrals.
  38. Thus, it has nine possible ISA jobs, but only helium
  39. three and helium.
  40. For our stable.
  41. William is seven times lighter than her, and sound travels
  42. in it three times faster than inner.
  43. That's why when you inhale it, your voices.
  44. High pitched helium is colorless gas, but when place in
  45. high voltage electric field, it exhibits a reddish orange glow.
  46. It has boiling point off minus 268 0.9 degrees Celsius
  47. at atmospheric pressure.
  48. This pressure him doesn't solidify but at 25 bars its
  49. melting point this minus 272 degrees Celsius.
  50. William has varying liquid forks, depending on the isotope Chilean.
  51. Four has to liquid forms that are chemically the same
  52. but different physical properties.
  53. 1st 1 exists at temperatures from its boiling point down
  54. to about minus 271 degrees Celsius.
  55. Below that, it becomes the second form, which has formal
  56. conductivity more than 1000 times greater than copper.
  57. That is higher than any known substance.
  58. It also exhibits superfluidity, which means that its viscosity or
  59. its resistance to flow drops dramatically.
  60. A superfluid substance behaves very strangely.
  61. It can flow upwards out of the container, even against
  62. the force of gravity, forming a fin film on the
  63. material. If placed in an unsealed vessel, it would travel
  64. indefinitely along any surface off any material.
  65. Let's come on helium free eyes.
  66. The forms free distinguishable liquid faces and two of which
  67. are super fluids.
  68. When comes down to the mixture of the two is
  69. it oaks.
  70. It separates a temperature below minus 272.4 degrees Celsius in
  71. two layers.
  72. One layer is practically pure helium free, whereas the other,
  73. this mostly helium for but retains about 6% off helium
  74. free. The solution off helium free in him four.
  75. It's accompanied by a cooling effect that can drop the
  76. temperature down to minus 273.14 degrees Celsius, which is near
  77. absolute zero in stars.
  78. William is formed by the nuclear fusion of hydrogen atoms.
  79. Most Killian present on Earth, however, is created by radioactive
  80. decay off heavy radioactive elements like uranium or plutonium.
  81. Alpha particles emitted by surgery.
  82. K consists off killing for nuclear.
  83. Now I'd like to tell you about applications of helium,
  84. But first, let's take a look at its production.
  85. Helium is extracted by fractional distillation from natural gas, which
  86. can contain up to 7% of helium, since it has
  87. the lowest boiling point of four elements low temperature and
  88. high pressure.
  89. I used to liquefy over there gases.
  90. Then it has to be purified by successive exposures to
  91. lowering temperatures in which all the remaining gases are precipitated.
  92. Out of the geishas mixture activated charcoal.
  93. It's used as a final purification step that results in
  94. almost pure helium with only trace amounts off.
  95. Neil helium is produced by only a few countries, which
  96. include poet William can also be supplied from the confection
  97. there on a large scale, but it's not very efficient.
  98. It's only about five parts per 1,000,000 by volume.
  99. Off its particles are present in the atmosphere £1000 off
  100. air years only, about free cubic meters off helium.
  101. It's measured at room temperature and under atmospheric pressure.
  102. William has many unique properties low boiling point, low density,
  103. low scalability, high formal conductivity and in darkness.
  104. So it's used for any application which can exploit these
  105. properties. Cragin X, for example, where the largest amount of
  106. helium are used involved going superconducting magnets in medical emery
  107. scanners or NMR spectrometers.
  108. The Large Hadron Collider uses almost 100 metric tons of
  109. this gas to call these magnets.
  110. It was also used in Apollo space missions to cool
  111. the fuel off space vehicles.
  112. Hill, you misused also pressure as fuel tax Indrajit proportion,
  113. especially in which liquid hydrogen is used because here you
  114. miss a guess at the liquid hydrogen temperature in arc
  115. welding it issues to protect world area and electrode from
  116. oxidation. It is especially useful in welding easily oxidized materials
  117. like aluminium.
  118. In this case, the in earnest off helium ISS utilized.
  119. Killian has a lot of other uses, like, for example,
  120. creating an inert atmosphere for various industrial processes leakers detection,
  121. such as in car air conditioning systems or industrial installations.
  122. It is also used in briefing mixtures, for example, for
  123. deep sea divers.
  124. As helium is absorbed and released by human body much
  125. faster than nitrogen, allowing for shorter the compression stops and
  126. under use is lifting airships as helium.
  127. It's much lighter than our and this safer compared to
  128. hydrogen. It is also used in the gas chromatography as
  129. a gas carrier due to its lightweight and inert nous.
  130. Another application of helium is in helium ion microscopes, which
  131. has sharper image with a large dip of field, compared
  132. toa other microscope like ECM.
  133. And finally it found a use in delivering Internet access
  134. to people people's homes as it is used in manufacturing
  135. fiber optic cables.
  136. To conclude my presentation, I'd like to say that helium
  137. is a very unique element due to its properties, and
  138. how can they be utilized in numerous industries other than
  139. party balloons and speaking with a squeaky voice when inhaling
  140. it. Most people don't pay much attention to hear him,
  141. even though without it the world would look very differently.
  142. Today, it's worth pointing out that he idiom is predominantly
  143. non renewable resource which is very limited on Earth, despite
  144. being the second most abundant element in the universe.
  145. Thank you for watching my presentation.