Tantalum

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Tantalum
73Ta
Nb

Ta

Db
hafniumtantalumtungsten
Ìhànsójú
gray blue
Àwọn ìdámọ́ wíwọ́pọ̀
Orúkọ, àmì-ìdámọ́, nọ́mbà tantalum, Ta, 73
Ìpèlóhùn /ˈtæntələm/ TAN-təl-əm; previously /tænˈtæliəm/ tan-TAL-ee-əm
Ẹ̀ka ẹ́límẹ̀nti transition metal
Ẹgbẹ́, àsìkò, àdìpò 56, d
Ìwúwo átọ́mù 180.94788
Ìtòléra ẹ̀lẹ́ktrónì [Xe] 4f14 5d3 6s2
2, 8, 18, 32, 11, 2
Physical properties
Phase solid
Density (near r.t.) 16.69 g·cm−3
Liquid density at m.p. 15 g·cm−3
Melting point 3290 K, 3017 °C, 5463 °F
Boiling point 5731 K, 5458 °C, 9856 °F
Heat of fusion 36.57 kJ·mol−1
Heat of vaporization 732.8 kJ·mol−1
Molar heat capacity 25.36 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 3297 3597 3957 4395 4939 5634
Atomic properties
Oxidation states 5, 4, 3, 2, -1 (mildly acidic oxide)
Electronegativity 1.5 (Pauling scale)
Ionization energies 1st: 761 kJ·mol−1
2nd: 1500 kJ·mol−1
Atomic radius 146 pm
Covalent radius 170±8 pm
Miscellanea
Crystal structure body-centered cubic
Tantalum has a body-centered cubic crystal structure
Magnetic ordering paramagnetic[1]
Electrical resistivity (20 °C) 131 nΩ·m
Thermal conductivity 57.5 W·m−1·K−1
Thermal expansion (25 °C) 6.3 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 3400 m·s−1
Young's modulus 186 GPa
Shear modulus 69 GPa
Bulk modulus 200 GPa
Poisson ratio 0.34
Mohs hardness 6.5
Vickers hardness 873 MPa
Brinell hardness 800 MPa
CAS registry number 7440-25-7
Àwọn ísótòpù dídúró jùlọ
Main article: Àwọn ísótòpù tantalum
iso NA half-life DM DE (MeV) DP
177Ta syn 56.56 h ε 1.166 177Hf
178Ta syn 2.36 h ε 1.910 178Hf
179Ta syn 1.82 a ε 0.110 179Hf
180Ta syn 8.125 h ε 0.854 180Hf
β 0.708 180W
180mTa 0.012% >1.2×1015 y
(not observed)
ε 0.929 180Hf
β 0.783 180W
IT 0.075 180Ta
181Ta 99.988% 181Ta is stable with 108 neutrons
182Ta syn 114.43 d β 1.814 182W
183Ta syn 5.1 d β 1.070 183W
· r


Itokasi[àtúnṣe | àtúnṣe àmìọ̀rọ̀]

  1. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.