ଲାନ୍ଥାନମ

Lanthanum,  ₅₇La

ସାଧାରଣ ଗୁଣ
ନାମ, ପ୍ରତୀକ	lanthanum, La
Appearance	silvery white
ଉଚ୍ଚାରଣ	/ˈlænθənəm/
Lanthanum in the periodic table
- ↑ La ↓ Ac barium ← lanthanum → cerium
ପରମାଣୁ କ୍ରମାଙ୍କ (Z)	57
ଶ୍ରେଣୀ, ବ୍ଳକ	group n/a, f-block
ପର୍ଯ୍ୟାୟ	period 6
ମୌଳିକ ପ୍ରକାର	lanthanide, sometimes considered a transition metal
ମାନକ ପରମାଣବିକ ଓଜନ (Ar)	138.90547
ଇଲେକ୍‌ଟ୍ରୋନ୍ ବିନ୍ୟାସ	[Xe] 5d1 6s2
per shell	2, 8, 18, 18, 9, 2
ଭୌତିକ ଗୁଣ
ଅବସ୍ଥା	solid
ଗଳନାଙ୍କ	1193 K ​(920 °C, ​1688 °F)
ସ୍ଫୁଟନାଙ୍କ	3737 K ​(3464 °C, ​6267 °F)
Density near r.t.	6.162 g/cm3
when liquid, at m.p.	5.94 g/cm3
Heat of fusion	6.20 kJ/mol
Heat of	402.1 kJ/mol
Molar heat capacity	27.11 J/(mol·K)
pressure (extrapolated) P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2005 2208 2458 2772 3178 3726
Atomic properties
Oxidation states	3, 2 (strongly basic oxide)
Electronegativity	Pauling scale: 1.10
Atomic radius	empirical: 187 pm
Covalent radius	207±8 pm
Miscellanea
Crystal structure	​hexagonal
Speed of sound thin rod	2475 m/s (at 20 °C)
Thermal expansion	(r.t.) (α, poly) 12.1 µm/(m·K)
Thermal conductivity	13.4 W/(m·K)
Electrical resistivity	(r.t.) (α, poly) 615 n Ω·m
Magnetic ordering	paramagnetic
Young's modulus	(α form) 36.6 GPa
Shear modulus	(α form) 14.3 GPa
Bulk modulus	(α form) 27.9 GPa
Poisson ratio	(α form) 0.280
Mohs hardness	2.5
Vickers hardness	491 MPa
Brinell hardness	363 MPa
CAS Number	7439-91-0
ଇତିହାସ
ଆବିଷ୍କାର	Carl Gustaf Mosander (1838)
Most stable isotopes of lanthanum
iso NA half-life DM DE (MeV) DP 137La syn 6×104 y ε 0.600 137Ba 138La 0.090% 1.05×1011 y ε 1.737 138Ba β− 1.044 138Ce 139La 99.910% 139La is stable with 82 neutrons

ଲାନ୍ଥାନମ ହେଉଛି ଏକ ରାସାୟନିକ ମୌଳିକ ଯାହାର ପ୍ରତୀକ La ଓ ପରମାଣୁ କ୍ରମାଙ୍କ ୫୭ ।

ଆହୁରି ପଢନ୍ତୁ

• The Industrial Chemistry of the Lanthanons, Yttrium, Thorium and Uranium, by R.J. Callow, Pergamon Press 1967
• Extractive Metallurgy of Rare Earths, by C.K. Gupta and N. Krishnamurthy, CRC Press 2005
• Nouveau Traite de Chimie Minerale, Vol. VII. Scandium, Yttrium, Elements des Terres Rares, Actinium, P. Pascal, Editor, Masson & Cie 1959
• Chemistry of the Lanthanons, by R.C. Vickery, Butterworths 1953

ବାହାର ଲିଙ୍କ

• WebElements.com – Lanthanum