Lutetium

Lutetium, ₇₁Lu

Lutetium
Pronunciation	/ljuːˈtiːʃiəm/ ​(lew-TEE-shee-əm)
Appearance	silvery white
Standard atomic weight Ar, std(Lu)	7002174966800000000♠174.9668(1)
Mass number	Lu:
Lutetium 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 Y ↑ Lu ↓ Lr ytterbium ← lutetium → hafnium
Atomic nummer (Z)	71
Group	group n/a
Period	period 6
Block	d-block
Element category	Lanthanide
Electron confeeguration	[Xe] 4f14 5d1 6s2
Electrons per shell	2, 8, 18, 32, 9, 2
Pheesical properties
Phase at STP	solit
Meltin pynt	1925 K ​(1652 °C, ​3006 °F)
Bylin pynt	3675 K ​(3402 °C, ​6156 °F)
Density (near r.t.)	9.841 g/cm3
when liquid (at m.p.)	9.3 g/cm3
Heat o fusion	ca. 22 kJ/mol
Heat o vapourisation	414 kJ/mol
Molar heat capacity	26.86 J/(mol·K)
Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 1906 2103 2346 (2653) (3072) (3663)
Atomic properties
Oxidation states	0, +1, +2, +3 waikly basic
Electronegativity	Pauling scale: 1.27
Atomic radius	empirical: 174 pm
Covalent radius	187±8 pm
Spectral lines o lutetium
Ither properties
Naitural occurrence	Lu: Primordial
Creestal structur	​hexagonal close-packed (hcp)
Thermal expansion	(r.t.) (poly) 9.9 µm/(m·K)
Thermal conductivity	16.4 W/(m·K)
Electrical resistivity	(r.t.) (poly) 582 n Ω·m
Magnetic orderin	paramagnetic
Young's modulus	68.6 GPa
Shear modulus	27.2 GPa
Bulk modulus	47.6 GPa
Poisson ratio	0.261
Vickers haurdness	1160 MPa
Brinell haurdness	893 MPa
CAS Nummer	7439-94-3
History
Diskivery	Georges Urbain an Carl Auer von Welsbach (1906)
First isolation	Carl Auer von Welsbach (1906)
Main isotopes o lutetium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 173Lu syn 1.37 y ε 173Yb 174Lu syn 3.31 y ε 174Yb 175Lu 97.41% - (α) 171Tm 176Lu 2.59% 3.78×1010 y β− 176Hf
Decay modes in parentheses are predictit, but hae nae yet been observed

Lutetium is a chemical element wi the seembol Lu an atomic nummer 71. It is a sillery white metal which resists corrosion in dry, but nae in moist, air. It is the last element in the lanthanide series, an tradeetionally coontit amang the rare yirds.