Deleng sumberé Hèliyum

{{Elementbox_header | number=2 | symbol=He | name=hèliyum | left=[[hidrogen]] | right=[[litiyum]] | above=-| below=[[néon|Ne]] | color1=#c0ffff | color2=green }}
{{Elementbox_series | [[gas mulia]] }}
{{Elementbox_groupperiodblock | group=18 | period=1 | block=s }}
{{Elementbox_appearance_img | He,2| ora duwé warna }}
{{Elementbox_atomicmass_gpm | [[1 E-27 kg|4,002602(2)]] }}
{{Elementbox_econfig | 1s<sup>2</sup> }}
{{Elementbox_epershell | 2 }}
{{Elementbox_section_physicalprop | color1=#c0ffff | color2=green }}
{{Elementbox_phase | [[gas]] }}
{{Elementbox_density_gplstp | 0,1786 }}
{{Elementbox_meltingpoint | k=(ing 2,5 MPa) 0,95 | c=-272,2 | f=-458,0 }}
{{Elementbox_boilingpoint | k=4,22 | c=-268,93 | f=-452,07 }}
{{Elementbox_heatfusion_kjpmol | 0,0138 }}
{{Elementbox_heatvaporiz_kjpmol | 0,0829 }}
{{Elementbox_heatcapacity_jpmolkat25 | 20,786 }}
{{Elementbox_vaporpressure_katpa | &nbsp; | &nbsp; | &nbsp; | &nbsp; | 3 | 4 | comment= }}
{{Elementbox_section_atomicprop | color1=#c0ffff | color2=green }}
{{Elementbox_crystalstruct | heksagonal atau bcc }}
{{Elementbox_ionizationenergies2 | 2372,3 | 5250,5 }}
{{Elementbox_atomicradiuscalc_pm | [[1 E-11 m|31]] }}
{{Elementbox_covalentradius_pm | [[1 E-11 m|32]] }}
{{Elementbox_vanderwaalsrad_pm | [[1 E-10 m|140]] }}
{{Elementbox_section_miscellaneous | color1=#c0ffff | color2=green }}
{{Elementbox_thermalcond_wpmkat300k | 151,3 m}}
{{Elementbox_isotopes_begin | isotopesof=hèliyum | color1=#c0ffff | color2=green }}
{{Elementbox_isotopes_stable | mn=3 | sym=He | na=0,000137%* | n=1 }}
{{Elementbox_isotopes_stable | mn=4 | sym=He | na=99,999863%* | n=2 }}
|-
| colspan="6" align="center" | *<small>Pangaji kang ditedahaké ya iku kanggo ing atmosfer,<br />kalimpahan ing papan liya mungel béda.</small>
{{Elementbox_isotopes_end}}
{{Elementbox_footer | color1=#c0ffff | color2=green }}
[[Barkas:HeNe Laser Build.webm|jmpl|Laser Hèliyum]]
'''Hèliyum''' ('''Helium''', He) iku [[unsur kimia]] kang ora duwé warna, ora ngganda, ora ana rasané, ora ngandhut racun, mèh [[inert]], monatomik, lan wujud unsur sepisanan ing seri [[gas mulia]] ing [[tabel périodik]] lan nduwé [[nomer atom]] 2. Titik umub lan titik leburé paling asor tinimbang unsur-unsur liya lan mung ana ing wangun gas kejaba ing kaanan "ekstrem". Kaanan ekstrem uga diperlokaké kanggo nyiptakaké sithik [[senyawa]] helium, kang kabèh ora stabil ing [[suhu lan tekanan standar]]. Helium nduwé [[isotop stabil]] kaloro kang langka kang karan [[helium-3]]. Sifat saka cuwèran varitas [[helium-4]]; helium I lan helium II; wigati kanggo para panliti kang nyinaoni [[mekanika kuantum]] (mligi ing fenomena [[superfluiditas]]) lan kanggo panliti kang nggolèki èfèk nyeraki suhu [[nol absolut]] kang didarbèni [[benda]] (kaya ta [[superkonduktivitas]]).

Helium iku unsur angka loro paling akèh lan paling ènthèng ing [[jagad raya]] lan salah siji unsur kang diciptakaké nalika [[nukleosintesis Big Bang]]. Ing Jagad Raya modhèren mèh kabèh helium anyar diciptakaké ing prosès [[fusi nuklir]] hidrogen ing njeron [[lintang]]. Ing [[Bumi]], unsur iki diciptakaké déning [[paluruhan radioaktif]] saka unsur kang luwih abot ([[partikel alfa]] ya iku nukleus helium). Sawisé panciptaané, sebagéyané kakandhut ing udara (gas alami) ing konsèntrasi tekan 7% volume. Helium dimurnèkaké saka udara déning prosès pamisahan suhu asor kang karan [[distilasi fraksional]].

Ing taun [[1868]], astronom [[Prancis]] [[Pierre Janssen]] [[panemon unsur kimia|ndhétèksi sepisanan]] helium minangka signatur [[spektroskopi|garis spektral]] kuning kang ora diweruhi saka cahya saka [[grahana srengéngé]]. Wiwit wektu iku kandhutan helium gedhé akèh tinemu ing ladhang gas alam ing [[Amérika Sarékat]], kang wujud panyedya gas gedhé dhéwé. Helium dipigunakaké ing [[kryogenik]], sistem ambegan laut jero, kanggo ngadhemaké [[magnet superkonduktor]], ing "[[helium dating]]", kanggo mlembungké [[balon]], kanggo ngangkat [[kapal udara]] lan minangka gas pangreksa kanggo panggunaan indhustri (kaya ta "[[arc welding]]") lan panuwuhan wafer [[silikon]]). Yèn wong nyedhot sithik gas iki bakal njalari owahing sauntara kualitas swarané.

== Réferènsi ==
;Artikel
<small>Menurut banyaknya penggunaan</small>
* ''The Encyclopedia of the Chemical Elements'', disunting déning Cifford A. Hampel, "Helium" artikel déning L. W. Brandt (New York; Reinhold Book Corporation; 1968; kaca 256-267) Library of Congress Catalog Card Number: 68-29938
* Nature's Building Blocks: An A-Z Guide to the Elements'', déning John Emsley (New York; Oxford University Press; 2001; kaca 175-179) ISBN 0-19-850340-7''
* Los Alamos National Laboratory (LANL.gov): Periodic Table, "Helium" [http://periodic.lanl.gov/elements/2.html] {{Webarchive|url=https://web.archive.org/web/20080602082826/http://periodic.lanl.gov/elements/2.html |date=2008-06-02 }} (ditilik tanggal 10 Oktober 2002 lan 25 Maret 2005)
* ''Guide to the Elements: Revised Edition'', déning Albert Stwertka (New York; Oxford University Press; 1998; kaca 22-24) ISBN 0-19-512708-0
* ''The Elements: Third Edition'', olèh John Emsley (New York; Oxford University Press; 1998; kaca 94-95) ISBN 0-19-855818-X
* United States Geological Survey (usgs.gov): Mineral Information for Helium  [http://minerals.usgs.gov/minerals/pubs/commodity/helium/heliumcs04.pdf] (ditilik 31 Maret 2005)
* ''The thermosphere: a part of the heterosphere'', olèh J. Vercheval [http://www.oma.be/BIRA-IASB/Public/Research/Thermo/Thermotxt.en.html] (ditilik 1 Apr 2005) 
* ''Isotopic Composition and Abundance of Interstellar Neutral Helium Based on Direct Measurements'',  Zastenker G.N. ''et al.'', [http://www.ingentaconnect.com/content/klu/asys/2002/00000045/00000002/00378626], dipublikasikaké ing [http://www.ingentaconnect.com/content/klu/asys Astrophysics], April 2002, vol. 45, no. 2, pp. 131-142(12) 
* ''[http://www3.interscience.wiley.com/cgi-bin/abstract/105558571/ABSTRACT Dynamic and thermodynamic properties of solid helium in the reduced all-neighbours approximation of the self-consistent phonon theory]{{Pranala mati|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}'', C. Malinowska-Adamska, P. Sŀoma, J. Tomaszewski, physica status solidi (b), Volume 240, Issue 1, Kaca 55-67; Diterbitaké kanthi ''Online'': 19 Sep 2003
* ''[http://www.yutopian.com/Yuan/TFM.html The Two Fluid Model of Superfluid Helium]'', S. Yuan, (ditilik 4 Apr 2005)
* ''Rollin Film Rates in Liquid Helium'', Henry A. Fairbank dan C. T. Lane, Phys. Rev. 76, 1209–1211 (1949), [http://prola.aps.org/abstract/PR/v76/i8/p1209_1 saka arsip ''online''] {{Webarchive|url=https://web.archive.org/web/20120113102307/http://prola.aps.org/abstract/PR/v76/i8/p1209_1 |date=2012-01-13 }}
* ''[http://cryowwwebber.gsfc.nasa.gov/introduction/liquid_helium.html Introduction to Liquid Helium] {{Webarchive|url=https://web.archive.org/web/20050901062951/http://cryowwwebber.gsfc.nasa.gov/introduction/liquid_helium.html |date=2005-09-01 }}'', ing the [[NASA]] [[Goddard Space Flight Center]] (ditilik 4 Apr 2005) 
* ''[http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1983ApOpt..22...10E&amp;db_key=AST Tests of vacuum VS helium in a solar telescope]'', Engvold, O.; Dunn, R. B.; Smartt, R. N.; Livingston, W. C.. Applied Optics, vol. 22, Jan. 1, 1983, p. 10-12.
* ''[http://www.mantleplumes.org/HeliumFundamentals.html Helium: Fundamental models]'', Don L. Anderson, G. R. Foulger & Anders Meibom (ditilik 5 Apr 2005)
* ''[http://www.scuba-doc.com/HPNS.html High Pressure Nervous Syndrome]'', Diving Medicine Online (ditilik 5 Apr 2005)

;Tabel
* WebElements.com lan EnvironmentalChemistry.com selaras karo pitedah ing [http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Elements Wikipedia's WikiProject Elements] (ditilik 10 Oktober 2002)

== Pranala njaba ==
;Umum
* [http://www.webelements.com/webelements/elements/text/He/key.html WebElements: Helium]
* [http://environmentalchemistry.com/yogi/periodic/He.html EnvironmentalChemistry.com – Helium] 
* [http://education.jlab.org/itselemental/ele002.html It's Elemental – Helium]

;Luwih dhetil
* [http://boojum.hut.fi/research/theory/helium.html Helium] ing [[Helsinki University of Technology]]; kalebu diagram fase tekanan-suhu helium-3 lan helium-4.

;Liya-liya
* [http://www.cganet.com/N2O/helium_safety.asp Kaamanan panggunaan helium yèn disedhot] {{Webarchive|url=https://web.archive.org/web/20050407081801/http://www.cganet.com/N2O/helium_safety.asp |date=2005-04-07 }}
* [http://www.phys.unsw.edu.au/PHYSICS_!/SPEECH_HELIUM/speech.html Fisika swara manungsa] kanthi conto rekaman audio

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