Template:Infobox protactinium

Protactinium, ₉₁Pa

Protactinium
Pronunciation	/ˌproʊtækˈtɪniəm/ ​(PROH-tak-TIN-ee-əm)
Appearance	bright, silvery metallic luster
Standard atomic weight Ar, std(Pa)	231.03588(1)
Protactinium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Pr ↑ Pa ↓ (Uqp) thorium ← protactinium → uranium
Atomic number (Z)	91
Group	group n/a
Period	period 7
Block	f-block
Element category	f-block
Electron configuration	[Rn] 5f2 6d1 7s2
Electrons per shell	2, 8, 18, 32, 20, 9, 2
Physical properties
Phase at STP	solid
Melting point	1841 K ​(1568 °C, ​2854 °F)
Boiling point	4300 K ​(4027 °C, ​7280 °F) (?)
Density (near r.t.)	15.37 g/cm3
Heat of fusion	12.34 kJ/mol
Heat of vaporization	481 kJ/mol
Atomic properties
Oxidation states	+2, +3, +4, +5 (a weakly basic oxide)
Electronegativity	Pauling scale: 1.5
Ionization energies	1st: 568 kJ/mol
Atomic radius	empirical: 163 pm
Covalent radius	200 pm
Spectral lines of protactinium
Other properties
Natural occurrence	from decay
Crystal structure	​body-centered tetragonal
Thermal expansion	~9.9 µm/(m·K) (at r.t.)
Thermal conductivity	47 W/(m·K)
Electrical resistivity	177 nΩ·m (at 0 °C)
Magnetic ordering	paramagnetic
CAS Number	7440-13-3
History
Prediction	Dmitri Mendeleev (1869)
Discovery and first isolation	Kasimir Fajans and Oswald Helmuth Göhring (1913)
Named by	Otto Hahn and Lise Meitner (1917–8)
Main isotopes of protactinium
Iso­tope Abun­dance Physics:Half-life (t1/2) Decay mode Pro­duct 229Pa syn 1.5 d ε 229Th 230Pa syn 17.4 d ε 230Th 231Pa 100% 3.276×104 y α 227Ac 232Pa syn 1.31 d β− 232U 233Pa trace 26.967 d β− 233U 234Pa trace 6.75 h β− 234U 234mPa trace 1.17 min β− 234U

Pa data m.p. cat
	in	calc from C	diff	report	ref
C	1568	—	—
K	1841	1841	0
F	2854	2854	0
max precision	0
WD
input	C: 1568, K: 1841, F: 2854
comment

Pa data b.p. cat
	in	calc from C	diff	report	ref
C	4027	—	—
K	4300	4300	0
F	7280	7281	-1
max precision	0
WD
input	C: 4027, K: 4300, F: 7280
comment	(?)

PTChemistry:protactinium

Th ← i'box Th	iso91Pa  infobox  isobox	→ U i'box U
Commons  Wikidata:Q1109  Wiktionary Indexes in PT: § below · Page

[]  Data sets read by {{Infobox element}}
Name and identifiers
Top image (caption, alt)
Pronunciation
Category (enwiki)
Standard atomic weight
most stable isotope
Natural occurrence
Phase at STP
Chemistry:Oxidation states
Spectral lines image
Physics:Electron configuration (cmt, ref)
Term symbol * (cmt, ref)
Wikidata *
* Not used in {{Infobox element}} (2019-02-03) See also {{Infobox element/symbol-to--navbox}}

References

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