Rhenium

Rhenium, ₇₅Re

Rhenium
Pronunciation	/ˈriːniəm/ ​(REE-nee-əm)
Appearance	sillery-white
Standard atomic weight Ar, std(Re)	7002186207000000000♠186.207(1)
Mass number	Re:
Rhenium in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Gowd Mercur (element) Thallium Leid (element) 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 Tc ↑ Re ↓ Bh tungsten ← rhenium → osmium
Atomic nummer (Z)	75
Group	group 7
Period	period 6
Block	d-block
Element category	Transeetion metal
Electron confeeguration	[Xe] 4f14 5d5 6s2
Electrons per shell	2, 8, 18, 32, 13, 2
Pheesical properties
Phase at STP	solit
Meltin pynt	3459 K ​(3186 °C, ​5767 °F)
Bylin pynt	5869 K ​(5596 °C, ​10105 °F)
Density (near r.t.)	21.02 g/cm3
when liquid (at m.p.)	18.9 g/cm3
Heat o fusion	60.43 kJ/mol
Heat o vapourisation	704 kJ/mol
Molar heat capacity	25.48 J/(mol·K)
Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 3303 3614 4009 4500 5127 5954
Atomic properties
Oxidation states	−3, −1, 0, +1, +2, +3, +4, +5, +6, +7 (a mildly acidic oxide)
Electronegativity	Pauling scale: 1.9
Ionisation energies	(more)
Atomic radius	empirical: 137 pm
Covalent radius	151±7 pm
Spectral lines o rhenium
Ither properties
Naitural occurrence	Re: Primordial
Creestal structur	​hexagonal close-packed (hcp)
Speed o soond thin rod	4700 m/s (at 20 °C)
Thermal expansion	6.2 µm/(m·K)
Thermal conductivity	48.0 W/(m·K)
Electrical resistivity	193 n Ω·m (at 20 °C)
Magnetic orderin	paramagnetic
Young's modulus	463 GPa
Shear modulus	178 GPa
Bulk modulus	370 GPa
Poisson ratio	0.30
Mohs haurdness	7.0
Vickers haurdness	2450 MPa
Brinell haurdness	1320 MPa
CAS Nummer	7440-15-5
History
Diskivery	Masataka Ogawa (1908)
First isolation	Masataka Ogawa (1908)
Named by	Walter Noddack, Ida Noddack, Otto Berg (1922)
Main isotopes o rhenium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 185Re 37.4% - (α) 181Ta 187Re 62.6% 4.12×1010 y α 183Ta β− 187Os
Decay modes in parentheses are predictit, but hae nae yet been observed

Rhenium is a chemical element wi the seembol Re an atomic nummer 75. It is a sillery-white, hivy, third-row transeetion metal in group 7 o the periodic table. Wi an estimatit average concentration o 1 pairt per billion (ppb), rhenium is ane o the rarest elements in the Yird's crust. The free element haes the third-heichest meltin pynt an heichest boilin pynt o ony element. Rhenium resembles manganese chemically an is obtained as a bi-product o molybdenum an copper ore's extraction an refinement. Rhenium shaws in its compoonds a wide variety o oxidation states rangin frae −1 tae +7.