మూస:Infobox protactinium

ప్రొటాక్టీనియం, ₀₀Pa

ప్రొటాక్టీనియం
Pronunciation	/ˌproʊtækˈtɪniəm/ ​(PROH-tak-TIN-ee-əm)
Appearance	bright, silvery metallic luster
Standard atomic weight Ar°(Pa)
	231.03588±0.00001 231.04±0.01 (abridged)
ప్రొటాక్టీనియం 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 Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium Pr ↑ Pa ↓ (Uqt) థోరియం ← ప్రొటాక్టీనియం → యురేనియం
Group	మూస:Infobox element/symbol-to-group/format
Period	period 7
Block	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
Atomic radius	empirical: 163 pm
Covalent radius	200 pm
Spectral lines of ప్రొటాక్టీనియం
Other properties
Natural occurrence	from decay
Crystal structure	​tetragonal
Thermal conductivity	47 W/(m⋅K)
Electrical resistivity	177 n Ω⋅m (at 0 °C)
Magnetic ordering	paramagnetic
CAS Number	7440-13-3
History
Prediction	Dmitri Mendeleev (1869)
Discovery	William Crookes (1900)
First isolation	William Crookes (1900)
Named by	Otto Hahn and Lise Meitner (1917–8)
Isotopes of ప్రొటాక్టీనియం

References

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