Unsur periode 1: Perbedaan antara revisi
Konten dihapus Konten ditambahkan
Baris 13:
[[Helium]] hampir selalu diletakkan di atas [[neon]] (yang merupakan anggota [[blok-p]]) dalam tabel periodik sebagai [[gas mulia]],<ref name="iupac">{{cite web|url = http://old.iupac.org/reports/periodic_table/|title = International Union of Pure and Applied Chemistry > Periodic Table of the Elements|publisher = IUPAC|accessdate = 2011-05-01}}</ref> meskipun ia kadang-kadang diletakkan di atas [[berilium]] karena kesamaan konfigurasi elektronnya.<ref name="janet-table">{{cite web |url = http://www.webelements.com/nexus/Janet_Periodic_Table|title = Janet periodic table|author = Winter, Mark|date = 1993–2011|work = WebElements|accessdate = January 19, 2012}}</ref>
==Unsur==
{| class="wikitable"
! colspan="3" href="periode tabel periodik" | [[Unsur kimia]]
! href="Hidrogenasi" | [[Deret kimia]]
! href="struktur atom" | [[Konfigurasi elektron]]
|- style="background-color: {{element color|diatomic nonmetal}}" href="atom"
| href="Blok-s" | 1
| href="elektron" | '''H'''
| [[Hidrogen]]
| [[Nonlogam diatomik]]
| 1s<sup href="gas mulia">1</sup>
|- style="background-color: #c0ffff" href="Unsur golongan 18"
| 2
| '''He'''
| [[Helium]]
| href="litium" | [[Gas mulia]]
| href="fluor" | 1s<sup href="tabel periodik">2</sup>
|}
===Hidrogen===
{{Main|Hidrogen}}
[[Berkas:Hydrogen_discharge_tube.jpg|left|thumb|150x150px|Tabung pembebas hidrogen]]
[[Berkas:Deuterium_discharge_tube.jpg|left|thumb|150x150px|Tabung pembebas deuterium]]
{{Unsur|Hidrogen|H|1}} Pada [[temperatur dan tekanan standar]], hidrogen tidak berwarna, tidak berbau, [[nonlogam]], tidak berasa, merupakan [[gas]] [[diatomik]] yang sangat [[Pembakaran|mudah terbakar]] dengan [[rumus molekul]] H<sub>2</sub>. Dengan [[massa atom]] 1,00794 [[Satuan massa atom|amu]], hidrogen adalah unsur paling ringan.<ref>{{cite web|accessdate = 2008-07-15|url = http://www.eia.doe.gov/kids/energyfacts/sources/IntermediateHydrogen.html|title = Hydrogen – Energy|publisher = Energy Information Administration}}</ref>
Hidrogen adalah unsur kimia paling [[Kelimpahan alami unsur|melimpah]], menyusun sekitar 75% massa unsur alam semesta.<ref>{{cite web |last = Palmer|first = David|date = November 13, 1997|url = http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/971113i.html|title = Hydrogen in the Universe|publisher = NASA|accessdate = 2008-02-05}}</ref> [[Bintang]] dalam [[deret utama]] memiliki komponen utama hidrogen dalam kondisi [[Plasma (wujud zat)|plasmanya]]. Unsur hidrogen relatif langka di [[Bumi]], dan secara industri diproduksi dari [[hidrokarbon]] seperti metana, namun setelahnya sebagian besar unsur hidrogen yang dihasilkan digunakan "sendiri" (artinya hanya berputar-putar di tempat produksinya), dengan pasar terbesar hampir terbagi rata antara peningkatan [[bahan bakar fosil]], seperti hydrocracking dan produksi [[amonia]], yang sebagian besar untuk pasar pupuk. Hidrogen dapat diproduksi dari air menggunakan proses [[elektrolisis]], tetapi proses ini secara komersial jauh lebih mahal daripada produksi hidrogen dari gas alam.<ref>{{cite web |author = Staff|year = 2007|url = http://www.fsec.ucf.edu/en/consumer/hydrogen/basics/production.htm|title = Hydrogen Basics — Production|publisher = Florida Solar Energy Center|accessdate = 2008-02-05}}</ref>
[[Isotop]] hidrogen yang paling banyak terdapat di alam, diketahui sebagai [[Hidrogen-1|protium]], memiliki satu [[proton]] tanpa [[neutron]].<ref>{{cite news|title = Fusion Power Is Still Facing Formidable Difficulties|work = The New York Times|date = 1971-03-11|author = Sullivan, Walter}}</ref> Dalam senyawa ionik, ia dapat bermuatan positif, menjadi [[kation]] yang merupakan proton telanjang, atau bermuatan negatif, menjadi [[anion]] yang dikenal sebagai [[hidrida]]. Hidrogen dapat membentuk senyawa dengan sebagian besar unsur dan terdapat dalam [[air]] serta sebagian besar [[senyawa organik]].<ref>{{cite encyclopedia|encyclopedia = [[Encyclopædia Britannica]]|year = 2008|title = hydrogen}}</ref> Ia memainkan peran yang sangat penting dalam [[Teori reaksi asam-basa|kimia asam-basa]], di mana banyak reaksi terlibat pertukaran proton antar molekul yang dapat larut.<ref>{{cite journal|title = Electron-Driven Acid-Base Chemistry: Proton Transfer from Hydrogen Chloride to Ammonia|date = 2008-02-15|volume = 319|issue = 5865|pages = 936–939|doi = 10.1126/science.1151614|author = Eustis, S. N.|journal = Science|pmid = 18276886|last2 = Radisic|first2 = D|last3 = Bowen|first3 = KH|last4 = Bachorz|first4 = RA|last5 = Haranczyk|first5 = M|last6 = Schenter|first6 = GK|last7 = Gutowski|first7 = M|bibcode = 2008Sci...319..936E}}</ref> Karena hanya atom netral yang dapat dianalisis menggunakan [[persamaan Schrödinger]], studi energetika dan [[Spektrum atom|spektrum]] atom hidrogen memainkan peran kunci dalam pengembangan [[mekanika kuantum]].<ref>{{cite encyclopedia|encyclopedia = [[Encyclopædia Britannica]]|year = 2008|title = Time-dependent Schrödinger equation}}</ref>
Interaksi hidrogen dengan berbagai logam sangat penting dalam [[metalurgi]], karena banyak logam dapat mengalami [[perapuhan hidrogen]],<ref>{{cite journal |last = Rogers|first = H. C.|title = Hydrogen Embrittlement of Metals|journal = Science|year = 1999|volume = 159|issue = 3819|pages = 1057–1064|doi = 10.1126/science.159.3819.1057|pmid = 17775040|bibcode = 1968Sci...159.1057R}}</ref> dan dalam pengembangan cara aman penyimpanannya sebagai bahan bakar.<ref>{{cite news |last = Christensen|first = C. H.|author2 = Nørskov, J. K.|author3 = Johannessen, T.|date = July 9, 2005|title = Making society independent of fossil fuels — Danish researchers reveal new technology|publisher = Technical University of Denmark|url = http://www.dtu.dk/English/About_DTU/News.aspx?guid=%7BE6FF7D39-1EDD-41A4-BC9A-20455C2CF1A7%7D|accessdate = 2008-03-28}}</ref> Hidrogen sangat mudah larut dalam banyak senyawa yang tersusun oleh [[logam tanah jarang]] dan [[logam transisi]]<ref name="Takeshita">{{cite journal |last = Takeshita|first = T.|author2 = Wallace, W.E.|author3 = Craig, R.S.|title = Hydrogen solubility in 1:5 compounds between yttrium or thorium and nickel or cobalt|journal = Inorganic Chemistry|year = 1974|volume = 13|issue = 9|pages = 2282–2283|doi = 10.1021/ic50139a050}}</ref> serta dapat larut dalam logam baik [[kristal]] maupun [[Padatan amorf|amorf]].<ref name="Kirchheim1">{{cite journal |last = Kirchheim|first = R.|author2 = Mutschele, T.|author3 = Kieninger, W|title = Hydrogen in amorphous and nanocrystalline metals|journal = Materials Science and Engineering|year = 1988|volume = 99|pages = 457–462|doi = 10.1016/0025-5416(88)90377-1}}</ref> Kelarutan hidrogen dalam logam mempengaruhi distorsi lokal atau ketidakmurnian [[kisi kristal]] logam.<ref name="Kirchheim2">{{cite journal |last = Kirchheim|first = R.|title = Hydrogen solubility and diffusivity in defective and amorphous metals|journal = Progress in Materials Science|year = 1988|volume = 32|issue = 4|pages = 262–325|doi = 10.1016/0079-6425(88)90010-2}}</ref>
<h3 />Helium
{{Main|Helium}}
<figure class="mw-halign-left">[./Berkas:Helium_discharge_tube.jpg [[Berkas:Helium_discharge_tube.jpg|link=|150x150px]]]<figcaption>Tabung pembebas helium</figcaption></figure>
<p>{{Unsur|Helium|He|2}} Helium adalah bahan kimia tak berwarna, tak berbau, tak berasa, tak beracun, [[monoatomik]] [[inert]] dan merupakan [[gas mulia]] pertama dalam [[tabel periodik]].<ref>{{cite web|accessdate = 2008-07-15|url = http://www.webelements.com/helium/|title = Helium: the essentials|publisher = WebElements}}</ref> Titik [[Titik lebur|lebur]] dan [[Titik didih|didihnya]] adalah yang paling rendah dibandingkan unsur-unsur lainnya dan hanya terdapat dalam bentuk [[gas]] kecuali dalam kondisi ekstrem.<ref>{{cite web|accessdate = 2008-07-15|url = http://www.webelements.com/helium/physics.html|title = Helium: physical properties|publisher = WebElements}}</ref></p>
<p>Helium pertama kali ditemukan pada tahun 1868 oleh astronom Perancis [[Pierre_Janssen]], yang [[Penemuan unsur kimia|pertama kali]] mendeteksi zat sebagai tanda [[Spektroskopi|garis spektrum]] kuning tak diketahui dalam cahaya dari [[gerhana matahari]].<ref>{{cite web|accessdate = 2008-07-15|url = http://encarta.msn.com/encyclopedia_762508746/pierre_janssen.html|title = Pierre Janssen|publisher = MSN Encarta}}</ref> Pada tahun 1903, cadangan helium yang besar ditemukan dalam [[ladang gas alam]] di Amerika Serikat, yang dikenal sebagai pemasok gas terbesar.<ref>{{cite web|accessdate = 2008-07-15|url = http://www.blm.gov/wo/st/en/info/newsroom/2007/january/NR0701_2.html|title = Where Has All the Helium Gone?|publisher = Bureau of Land Management|date = 2007-01-18|author = Theiss, Leslie}}</ref> Helium digunakan dalam [[kriogenik]],<ref>{{cite book|title = Cryogenic Engineering: Fifty Years of Progress|author = Timmerhaus, Klaus D.|date = 2006-10-06|publisher = Springer|isbn = 0-387-33324-X}}</ref> sistem pernapasan laut-dalam<ref>{{cite journal|title = Helium voice unscrambling|author = Copel, M.|journal = Audio and Electroacoustics|volume = 14|issue = 3|date = September 1966|pages = 122–126|doi = 10.1109/TAU.1966.1161862}}</ref>, untuk mendinginkan [[Magnet superkonduksi|magnet superkonduktor]], dan dalam [[Penanggalan Helium|penanggalan helium]],<ref>{{cite encyclopedia|encyclopedia = [[Encyclopædia Britannica]]|year = 2008|title = helium dating}}</ref> untuk pengisi [[balon]] udara,<ref>{{cite web|accessdate = 2008-07-15|url = http://www.howstuffworks.com/helium.htm|title = How Helium Balloons Work|publisher = How Stuff Works|author = Brain, Marshall}}</ref>, sebagai pengangkat [[kapal udara]],<ref>{{cite web|accessdate = 2008-07-15|url = http://www.popsci.com/military-aviation-space/article/2008-07/return-blimp|title = The Return of the Blimp|work = Popular Science|date = 2008-07-10|author = Jiwatram, Jaya}}</ref> dan sebagai gas pelindung untuk penggunaan industri seperti [[Arc welding|pengelasan]] dan pengembangan wafer [[silikon]].<ref>{{cite journal|title = When good GTAW arcs drift; drafty conditions are bad for welders and their GTAW arcs.|journal = Welding Design & Fabrication|date = 2005-02-01}}</ref> Menghirup [[Volume|sedikit]] gas ini akan mengubah sementara timbre dan kualitas suara manusia.<ref>{{cite web|accessdate = 2008-07-15|url = http://www.sciam.com/article.cfm?id=why-does-inhaling-helium|title = Why does inhaling helium make one's voice sound strange?|work = Scientific American|date = 2006-09-04|author = Montgomery, Craig}}</ref> Perilaku fasa dua fluida helium-4 cair, helium I dan helium II, penting bagi peneliti yang mempelajari [[mekanika kuantum]] dan terutama fenomena [[superfluiditas]],<ref>{{cite web|accessdate = 2008-07-15|url = http://www.sciencedaily.com/releases/2004/09/040903085531.htm|title = Probable Discovery Of A New, Supersolid, Phase Of Matter|publisher = Science Daily|date = 2004-09-03}}</ref> dan hal tersebut nampak pada efek bahwa pada temperatur hampir [[nol mutlak]], materi mengalami [[superkonduktivitas]].<ref>{{cite news|title = Scientists See Peril In Wasting Helium; Scientists See Peril in Waste of Helium|work = The New York Times|date = 1979-08-21|author = Browne, Malcolm W.}}</ref></p>
<p>Helium is the second lightest element and is the second most [[Chemical abundance|abundant]] in the observable universe.<ref>{{cite web|accessdate = 2008-07-15|url = http://www.webelements.com/helium/geology.html|title = Helium: geological information|publisher = WebElements}}</ref> Most helium was formed during the [[Big_Bang]], but new helium is being created as a result of the [[Nuclear_fusion]] of hydrogen in [[Star|stars]].<ref>{{cite web|accessdate = 2008-07-15|url = http://www.newscientist.com/article/mg12517027.000-origin-of-the-chemical-elements.html|title = Origin of the chemical elements|work = New Scientist|date = 1990-02-03|author = Cox, Tony}}</ref> On [[Earth]], helium is relatively rare and is created by the natural [[Radioactive decay|decay]] of some radioactive elements<ref>{{cite news|title = Helium supply deflated: production shortages mean some industries and partygoers must squeak by.|publisher = Houston Chronicle|date = 2006-11-05}}</ref> because the [[Alpha particle|alpha particles]] that are emitted consist of helium [[Atomic nucleus|nuclei]]. This radiogenic helium is trapped with [[Natural_gas]] in concentrations of up to seven percent by volume,<ref>{{cite web|accessdate = 2008-07-15|url = http://www.aapg.org/explorer/2008/02feb/helium.cfm|title = Helium a New Target in New Mexico|publisher = American Association of Petroleum Geologists|date = 2008-02-02|author = Brown, David}}</ref> from which it is extracted commercially by a low-temperature separation process called [[Fractional_distillation]].<ref>{{cite news|title = Where Do We Get the Helium We Use?|publisher = The Science Teacher|date = 2006-12-01|author = Voth, Greg}}</ref></p><references />
== Unsur ==
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