ହିଲିଅମ

ଉଇକିପିଡ଼ିଆ ରୁ
Helium
2He
-

He

Ne
hydrogenheliumlithium
ଭୌତିକ ରୁପ
colorless gas, exhibiting a red-orange glow when placed in a high-voltage electric field


Spectral lines of helium
ସାଧାରଣ ଧର୍ମ
ନାମ, ପ୍ରତୀକ,
ପରମାଣୁ କ୍ରମାଙ୍କ
helium, He,
2
ଉଚ୍ଚାରଣ /ˈhliəm/ hee-lee-əm
ମୌଳିକ ପ୍ରକାର noble gases
ଶ୍ରେଣୀ, ପର୍ଯ୍ୟାୟ, ବ୍ଲକ୍ 18 (noble gases), 1, s
ମାନକ ପରମାଣବିକ ଓଜନ 4.002602(2)
ଇଲେକ୍‌ଟ୍ରୋନ୍ ବିନ୍ୟାସ 1s2
2
Electron shells of helium (2)
ଇତିହାସ
ଆବିଷ୍କାର Pierre Janssen, Norman Lockyer (1868)
First isolation William Ramsay, Per Teodor Cleve, Abraham Langlet (1895)
ଭୌତିକ ଧର୍ମ
ଅବସ୍ଥା gas
ଘନତା (0 °C, 101.325 kPa)
0.1786 g/L
Liquid density at m.p. 0.145 g·cm−3
Liquid density at b.p. 0.125 g·cm−3
ଗଳନାଙ୍କ (at 2.5 MPa) 0.95 K, −272.20 °C, −457.96 °F
ସ୍ଫୁଟନାଙ୍କ 4.22 K, −268.93 °C, −452.07 °F
କ୍ରିଟିକାଲ୍ ପଏଣ୍ଟ 5.19 K, 0.227 MPa
Heat of fusion 0.0138 kJ·mol−1
Heat of vaporization 0.0829 kJ·mol−1
Molar heat capacity 5R/2 = 20.786 J·mol−1·K−1
Vapor pressure (defined by ITS-90)
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K)     1.23 1.67 2.48 4.21
Atomic properties
Oxidation states 0
Electronegativity no data (Pauling scale)
Ionization energies 1st: 2372.3 kJ·mol−1
2nd: 5250.5 kJ·mol−1
Covalent radius 28 pm
Van der Waals radius 140 pm
Miscellanea
Crystal structure hexagonal close-packed
Magnetic ordering diamagnetic[୧]
Thermal conductivity 0.1513 W·m−1·K−1
Speed of sound 972 m·s−1
CAS registry number 7440-59-7
Most stable isotopes
Main article: Isotopes of helium
iso NA half-life DM DE (MeV) DP
3He 0.000137%* 3He is stable with 1 neutron
4He 99.999863%* 4He is stable with 2 neutrons
*Atmospheric value, abundance may differ elsewhere.
· r

ହିଲିଅମ (ଇଂରାଜୀ: Helium) ହେଉଛି ଏକ ରାସାୟନିକ ମୌଳିକ । ଏହାର ପ୍ରତୀକ Heପରମାଣୁ କ୍ରମାଙ୍କ ୨ ଅଟେ ।

== ଇତିହାସ ==Evidence of helium was first detected on August 18, 1868 as a bright yellow line with a wavelength of 587.49 nanometres in the spectrum of the chromosphere of the Sun, by French astronomer Pierre Janssen during a total solar eclipse in Guntur, India. This line was initially assumed to be sodium. On October 20 of the same year, English astronomer Norman Lockyer observed a yellow line in the solar spectrum, which he named the D3 line, for it was near the known D1 and D2 lines of sodium, and concluded that it was caused by an element in the Sun unknown on Earth. He and English chemist Edward Frankland named the element with the Greek word for the Sun. On 26 March 1895 British chemist William Ramsay isolated helium on Earth by treating the mineral cleveite with mineral acids. Ramsay was looking for argon but, after separating nitrogen and oxygen from the gas liberated by sulfuric acid, noticed a bright-yellow line that matched the D3 line observed in the spectrum of the Sun. These samples were identified as helium by Lockyer and British physicist William Crookes. It was independently isolated from cleveite the same year by chemists Per Teodor Cleve and Abraham Langlet in Uppsala, Sweden, who collected enough of the gas to accurately determine its atomic weight. Helium was also isolated by the American geochemist William Francis Hillebrand prior to Ramsay's discovery when he noticed unusual spectral lines while testing a sample of the mineral uraninite. Hillebrand, however, attributed the lines to nitrogen. His letter of congratulations to Ramsay offers an interesting case of discovery and near-discovery in science. In 1907, Ernest Rutherford and Thomas Royds demonstrated that an alpha particle is a helium nucleus. In 1908, helium was first liquefied by Dutch physicist Heike Kamerlingh Onnes by cooling the gas to less than one kelvin. He tried to solidify it by further reducing the temperature but failed because helium does not have a triple point temperature where the solid, liquid, and gas phases are at equilibrium. It was first solidified in 1926 by his student Willem Hendrik Keesom by subjecting helium to 25 atmospheres of pressure. In 1938, Russian physicist Pyotr Leonidovich Kapitsa discovered that helium-4 has almost no viscosity at temperatures near absolute zero, a phenomenon now called superfluidity. In 1972, the same phenomenon was observed in helium-3 by American physicists Douglas D. Osheroff, David M. Lee, and Robert C. Richardson.

Notes === ବୈଜ୍ଞାନିକ ଆବିଷ୍କାର ===Discovery Information Who: Sir William Ramsey, Nils Langet, P T Cleve When: 1895 Where: Scotland/Sweden

Name Origin Greek: helios (sun). ===ଉତ୍ପାଦନ===Sources Found in natural gas deposits and in the air (5 parts per billion) Constantly lost to space; replenished by radioactive decay (alpha particles). Helium is the second most abundant element in the universe by mass (25%). Most of the helium supplied around the world comes from the area around Amarillo, Texas. Annual commercial production is around 4500 tons.

Abundance

Universe: 2.3 x 105 ppm (by weight)  
Sun: 2.3 x 105 ppm (by weight)  
Atmosphere: 5.2 ppm 
Earth's Crust: 0.008 ppm 
Seawater: 7 x 10-6 ppm

ଧର୍ମ[ସମ୍ପାଦନା]

ହିଲିୟମ ପରମାଣୁ[ସମ୍ପାଦନା]

note:Helium has the lowest melting and boiling point of any element. Liquid Helium is called a "quantum fluid" as it displays atomic properties on a macroscopic scale. The viscosity of liquid helium is 25 micropoises (water has a viscosity of 10,000 micropoises). As helium is cooled below its transition point, it has an unusual property of superfluidity with a viscosity approaching zero micropoises. In addition, liquid helium has extremely high thermal conductivity. Helium is the second most abundant and second lightest element in the periodic table. It is also the least reactive of all the group 18 (noble gases) elements. One cubic metre of helium will lift 1kg. Helium is the preferred choice for airships as although it is more expensive it is not flammable and has 92% the lifting power of hydrogen. The voice of a person who has inhaled helium temporarily sounds high-pitched, resembling those of the cartoon characters "Alvin and the Chipmunks". This is because the speed of sound in helium is nearly three times that in air. Although the vocal effect of inhaling helium may be amusing, it can be dangerous if done to excess since helium is a simple asphyxiant, thus it displaces oxygen needed for normal respiration. Death by asphyxiation will result within minutes if pure helium is breathed continuously.

ତରଳ ଓ ଗ୍ୟାସୀୟ ଅବସ୍ଥା[ସମ୍ପାଦନା]

କଠିନ ଓ ପ୍ଲାଜ୍‌ମା ଅବସ୍ଥା[ସମ୍ପାଦନା]

== ସମସ୍ଥାନିକ ==3He [1 neutrons] Abundance: 0.000137% Stable with 1 neutron Extraplanetary material, such as lunar and asteroid regolith, have trace amounts of helium-3 from being bombarded by solar winds. The Moon's surface contains helium-3 at concentrations on the order of 0.01 ppm.[


4He [2 neutrons] Abundance: 99.999863% Stable with 2 neutrons Liquid helium-4 can be cooled to about 1 kelvin using evaporative cooling.


5He [3 neutrons] Abundance: Half life: 7.00(30) x 10-24 seconds Decays to 4He. Highly unstable, decays to 4He.


6He [4 neutrons] Abundance: Half life: 806.7(15) ms [ beta- ] Decays to 6Li. Produced from 7He or 11Li.


7He [5 neutrons] Abundance: Half life: 2.9(5)-21 seconds Highly unstable, decays to 6He.


8He [6 neutrons] Abundance: Half life: 119.0(15) ms Produced from 9He, decomposes to 7Li through beta decay then emits a delayed neutron.


9He [7 neutrons] Abundance: Half life: 7(4) x 10-21 seconds Highly unstable, decays to 8He.


10He [8 neutrons] Abundance: Half life: 2.7(18) x 10-21 seconds Highly unstable, decays to 9He.

==ବ୍ୟବହାର==Used in balloons as it is lighter than air, and unlike hydrogen, not flammable; deep sea diving and welding. Also used in very low temperature research and nuclear power plant coolant. Future possible uses include use as coolant for nuclear fusion power plants and in superconducting electric systems. At extremely low temperatures, liquid helium is used to cool certain metals to produce superconductivity, such as in superconducting magnets used in magnetic resonance imaging. Helium at low temperatures is also used in cryogenics. Because it is inert, helium is used as a protective gas in growing silicon and germanium crystals, in titanium and zirconium production, in gas chromatography, and as an atmosphere for protecting historical documents. This property also makes it useful in supersonic wind tunnels

ଟୀକା[ସମ୍ପାଦନା]

  1. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.

ଆଧାର[ସମ୍ପାଦନା]

ବାହାର ଆଧାର[ସମ୍ପାଦନା]

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