text: # Protactinium
  Chăng-kō̤ Mìng-dĕ̤ng-ngṳ̄ Háng-cê gì bēng-buōng. / 參考閩東語漢字其版本。
  Protactinium sê siŏh cṳ̄ng gĭng-sṳ̆k, iâ sê siŏh cṳ̄ng huá-hŏk nguòng-só.  Nguòng-cṳ̄ sê̤ṳ-só sê 91, huá-hŏk hù-hô̤ sê Pa.
title: Protactinium
wikitext: {{twinLAT|鏷}}
  {{Infobox element
  |number=91
  |symbol=Pa
  |name=Protactini
  |enname=protactinium
  |laname=protactinium
  |left=[[thorium|Thori]]
  |right=[[Iù (gĭng-sṳ̆k)|Urani]]
  |above=[[praseodymium|Praseodymi]]
  |below=(Uqt)
  |series=actinium-hiê
  |period=7
  |block=f
  |group=n/a
  |appearance=bright, silvery metallic luster
  |image name=
  |atomic mass=231.03588
  |atomic mass ref=<ref name="IUPAC">[http://www.ciaaw.org/atomic-weights.htm Standard Atomic Weights 2013]. [[Commission on Isotopic Abundances and Atomic Weights]]</ref>
  |atomic mass 2=2
  |atomic mass comment=
  |electron configuration=&#91;[[radon|Rn]]&#93; 5f<sup>2</sup> 6d<sup>1</sup> 7s<sup>2</sup>
  |electrons per shell=2, 8, 18, 32, 20, 9, 2
  |phase=gó-tā̤
  |density gpcm3nrt=15.37
  |melting point K=1841
  |melting point C=1568
  |melting point F=2854
  |boiling point K=4300
  |boiling point C=4027
  |boiling point F=7280
  |boiling point comment=(?)
  |heat fusion=12.34
  |heat vaporization=481
  |crystal structure=tetragonal
  |crystal structure ref=<ref name=str>{{cite journal|last1=Donohue|first1=J.|title=On the crystal structure of protactinium metal|journal=Acta Crystallographica|volume=12|pages=697|year=1959|doi=10.1107/S0365110X59002031|issue=9}}</ref>
  |oxidation states=2, 3, 4, '''5'''
  |oxidation states comment=(a weakly [[base (chemistry)|basic]] oxide)
  |electronegativity=1.5
  |number of ionization energies=1
  |ionization energy 1=568
  |atomic radius=163
  |covalent radius=200
  |magnetic ordering=[[paramagnetic]]
  |magnetic ordering ref=<ref name=magnet>{{cite book | url = http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf | chapter = Magnetic susceptibility of the elements and inorganic compounds | editor = Lide, D. R. | title = CRC Handbook of Chemistry and Physics | edition = 86th | location = Boca Raton (FL) | publisher = CRC Press | year = 2005 | isbn = 0-8493-0486-5 | accessdate = 2018-06-03 | archive-date = 2011-03-03 | archive-url = https://web.archive.org/web/20110303222309/http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf | deadurl =  }}</ref>
  |electrical resistivity unit prefix=n
  |electrical resistivity at 0=177
  |thermal conductivity=47
  |thermal expansion=~9.9
  |thermal expansion ref=<ref>{{cite book|chapter=Chapter 2. Thermal Expansion|url=http://www.owlnet.rice.edu/~msci301/ThermalExpansion.pdf|page=11|publisher=ASM International|title=ASM Ready Reference: Thermal Properties of Metals |editor=Cverna, Fran |year=2002|isbn=0871707683}}</ref>
  |thermal expansion comment=(at&nbsp;{{abbr|r.t.|room temperature}})
  |CAS number=7440-13-3
  |isotopes=
  {{infobox element/isotopes decay | mn=229 | sym=Pa
   | na=[[synthetic radioisotope|syn]] | hl=1.5&nbsp;d
   | dm=[[electron capture|ε]] | de=0.311 | link1=thorium-229 | pn=229 | ps=Th}}
  {{infobox element/isotopes decay | mn=230 | sym=Pa
   | na=syn | hl=17.4&nbsp;d
   | dm=ε | de=1.310 | | link1=thorium-230 | pn=230 | ps=Th}}
  {{infobox element/isotopes decay | mn=231 | sym=Pa
   | na=100% | hl=3.276×10<sup>4</sup>&nbsp;y
   | dm=[[alpha decay|α]] | de=5.150 | link1=actinium-227 | pn=227 | ps=Ac}}
  {{infobox element/isotopes decay | mn=232 | sym=Pa
   | na=syn | hl=1.31&nbsp;d
   | dm=[[beta emission|β<sup>−</sup>]] | de=1.337 | link1=uranium-232 | pn=232 | ps=U}}
  {{infobox element/isotopes decay | mn=233 | sym=Pa
   | na=[[trace radioisotope|trace]] | hl=26.967&nbsp;d
   | dm=β<sup>−</sup> | de=0.5701 | link1=uranium-233 | pn=233 | ps=U}}
  {{infobox element/isotopes decay | mn=234 | sym=Pa
   | na=trace | hl=6.75&nbsp;h
   | dm=β<sup>−</sup> | de=2.195 | pn=234 | ps=U}}
  {{infobox element/isotopes decay | mn=234[[Meta state|m]] | sym=Pa
   | na=trace | hl=1.17&nbsp;min
   | dm=β<sup>−</sup> | de=2.29 | link1=uranium-234 | pn=234 | ps=U}}
  |isotopes comment=
  |predicted by=[[Dmitri Mendeleev]]
  |prediction date=1869
  |discovery and first isolation by=[[William Crookes]]
  |discovery date=1900
  |named by=[[Otto Hahn]] and [[Lise Meitner]]
  |named date=1917–8
  }}
  '''Protactinium''' sê siŏh cṳ̄ng [[gĭng-sṳ̆k]], iâ sê siŏh cṳ̄ng [[huá-hŏk nguòng-só]].  [[Nguòng-cṳ̄ sê̤ṳ-só]] sê 91, huá-hŏk hù-hô̤ sê Pa.
  ==Huá-hŏk séng-cék==
  
  ==Éng-ê̤ṳng==
  
  ==Cié-chṳ̄==
  
  ==Chăng-kō̤ cṳ̆-lâiu==
  {{reflist}}
  
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  [[分類:Huá-hŏk nguòng-só]]