Lutetium

Lutetium,  ₇₁Lu

General properties
Name, seembol	lutetium, Lu
Appearance	silvery white
Pronunciation	/ljuːˈtiːʃiəm/ lew-TEE-shee-əm
Lutetium in the periodic cairt
Y ↑ Lu ↓ Lr ytterbium ← lutetium → hafnium
Atomic nummer (Z)	71
Group, block	group n/a, d-block
Period	period 6
Element category	lanthanide, sometimes considered a transeetion metal
Staundart atomic wicht (Ar)	174.9668(4)
Electron configuration	[Xe] 6s2 4f14 5d1
per shell	2, 8, 18, 32, 9, 2
Pheesical properties
Phase	solid
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	3, 2, 1 (weakly basic oxide)
Electronegativity	Pauling scale: 1.27
Atomic radius	empirical: 174 pm
Covalent radius	187±8 pm
Miscellanea
Crystal 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
Discovery	Georges Urbain an Carl Auer von Welsbach (1906)
First isolation	Carl Auer von Welsbach (1906)
Maist stable isotopes o lutetium
iso NA hauf-life DM DE (MeV) DP 173Lu syn 1.37 y ε 0.671 173Yb 174Lu syn 3.31 y ε 1.374 174Yb 175Lu 97.41% - (α) 1.6197 171Tm 176Lu 2.59% 3.78×1010 y β− 1.193 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.