Tantalum

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Tantalum Quick Reference

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Notes

Symbol

Ta

Atomic Number

73

Atomic Weight

Rounded

180.9

for regular calculations

Standard

180.94788 ± 0.00002

for precise calculations

Oxidation States

 5

more common

 4

less common with disagreement

 3

less common with disagreement

 2

less common

 1

less common

-1

less common

-3

less common

Pauling Electronegativity

1.5

Electron Configuration

Orbital Occupancy

[Xe] 4f14 5d3 6s2

[Xe] represents the closed-shell electron configuration of xenon

Orbital Filling Order

[Xe] 6s2 4f14 5d3

[Xe] represents the closed-shell electron configuration of xenon

Term Symbol

4F3/2

see expanded configuration ...

Ionization Energies

I (1)

7.54957 eV

Electron Affinity

0.322 ± 0.012 eV

 2600 ± 100 cm-1

Density

liquid, 3290.15 K

15.000 g/ml 

solid, 25 °C

16.400 g/cm3

Molar Volume

solid, 298 K, 1 atm

10.85 cm3/mol

Melting Point

1 atm

3280 K

Boiling Point

1 atm

5731.15 K

Thermal Conductivity

solid

400 K

57.8 W/(m K)

300 K

57.5 W/(m K)

298.2 K

57.5 W/(m K)

273.2 K

57.4 W/(m K)

200 K

57.5 W/(m K)

interpolated

see all 52 conductivities ...

Pyykkö Covalent Radius

single bond

146 pm

double bond

126 pm

triple bond

119 pm

Atomic Radius

147 pm

Enthalpy of Fusion

1 atm

31.4 kJ/mol

Enthalpy of Vaporization

1 atm

753.1 kJ/mol

Quantity

Tantalum Atomic Structure

Notes

Ionization Energies

I (1)

7.54957 eV

Electron Affinity

0.322 ± 0.012 eV

 2600 ± 100 cm-1

Electron Binding Energies

K    (1s)

67416 eV  

LI   (2s)

11682 eV  

LII  (2p1/2)

11136 eV  

LIII (2p3/2)

 9881 eV  

see all 19 energies ...

Electron Configuration

Orbital Occupancy

[Xe] 4f14 5d3 6s2

[Xe] represents the closed-shell electron configuration of xenon

Orbital Filling Order

[Xe] 6s2 4f14 5d3

[Xe] represents the closed-shell electron configuration of xenon

Term Symbol

4F3/2

see expanded configuration ...

Clementi-Raimondi Effective Nuclear Charge

1s

Orbital Exponent

71.5837

ζ

Principle Quantum Number

1

n

Effective Nuclear Charge

71.5837

Zeff = ζ × n

2s

Orbital Exponent

26.9649

ζ

Principle Quantum Number

2

n

Effective Nuclear Charge

53.9298

Zeff = ζ × n

see all 14 effective nuclear charges ...

Screening Percentage

88.1%

Fluorescence Yields

ωK

0.952

ωL1

0.144

ωL2

0.28 

ωL3

0.251

Coster-Kronig Yields

F12

0.118

F13

0.328

F23

0.134

Quantity

Tantalum Physical Properties

Notes

Density

liquid, 3290.15 K

15.000 g/ml 

solid, 25 °C

16.400 g/cm3

Molar Mass

Rounded

180.9 g/mol

for regular calculations

Standard

180.94788 ± 0.00002 g/mol

for precise calculations

Molar Volume

solid, 298 K, 1 atm

10.85 cm3/mol

Physical Form

gray metal

Linear Thermal Expansion Coefficient

25 °C

6.3×10-6 K-1

293 K

6.6×10-6 K-1

280 K

6.6×10-6 K-1

273 K

6.5×10-6 K-1

260 K

6.5×10-6 K-1

see all 22 coefficients ...

Speed of Sound

solid, 291 K

3400 m/s

Specific Gravity

68 °F, water at 4 °C (39.2 °F)

metal

16.65

powder

14.40

Young's Modulus

185.7 GPa

Poisson's Ratio

0.342

Electrical Resistivity

solid

200 K

8.655×10-8 Ohm m

273 K

12.20×10-8 Ohm m

293 K

13.15×10-8 Ohm m

300 K

13.48×10-8 Ohm m

400 K

18.22×10-8 Ohm m

see all 65 resistivities ...

Contact Potential

4.1 eV

Photoelectric Work Function

4.14 eV

Thermionic Work Function

4.19 eV

Superconducting Transition Temperature

ambient pressure

4.483 K

43 GPa

4.5 K  

maximum temperature

0 Pa

4.483 K

Superconducting Critical Magnetic Field at Absolute Zero

830×10-4 T

Superconducting Energy Gap

0 K

14×10-4 eV

Mineralogical Hardness

6.5

Vickers Hardness

obtained by electron beam fusion

293 K

873 MN/m2

673 K

804 MN/m2

see all 6 hardnesses ...

Reflectivity

surface polished

0.5 μm

38%

0.6 μm

45%

0.8 μm

64%

see all 8 reflectivities ...

Isothermal Bulk Modulus

300 K

200 GPa

Isothermal Compressibility

300 K

0.0050 GPa-1

Gram Atomic Volume

11 cm3

Quantity

Tantalum Atomic Interaction

Notes

Oxidation States

 5

more common

 4

less common with disagreement

 3

less common with disagreement

 2

less common

 1

less common

-1

less common

-3

less common

Pauling Electronegativity

1.5

Allred-Rochow Electronegativity

1.33

Configuration Energy

electron volt units

7.93 eV

Pauling units

1.34   

Nagle Electronegativity

1.26

Pearson Absolute Electronegativity

4.11 eV

Smith Electronegativity

oxidation state: 5

1.8

Chemical Hardness

3.79 eV

Cohesive Energy

per mole

782 kJ/mol    

per atom

  8.10 eV/atom

Quantity

Tantalum Thermodynamics

Notes

Melting Point

1 atm

3280 K

Boiling Point

1 atm

5731.15 K

Thermal Conductivity

solid

400 K

57.8 W/(m K)

300 K

57.5 W/(m K)

298.2 K

57.5 W/(m K)

273.2 K

57.4 W/(m K)

200 K

57.5 W/(m K)

interpolated

see all 52 conductivities ...

Critical Point

10250 K

Vapor Pressure

5361 °C

100 kPa

4666 °C

10 kPa

4122 °C

1 kPa

3684 °C

100 Pa

3324 °C

10 Pa

3024 °C

1 Pa

Enthalpy of Fusion

1 atm

31.4 kJ/mol

Enthalpy of Vaporization

1 atm

753.1 kJ/mol

Isobaric Molar Heat Capacity

298.15 K, 1 bar

25.36 J/(mol K)

Isobaric Specific Heat Capacity

298.15 K, 1 bar

0.140 J/(g K)

Electronic Heat Capacity Coefficient

5.87 mJ/(mol K2)

Debye Temperature

Low Temperature Limit ( 0 K )

246 K

Room Temperature ( 298 K )

225 K

Quantity

Tantalum Identification

Notes

CAS Number

7440-25-7

ICSC Number

powder

1596

RTECS Number

WW5505000

UN Number

3089

Quantity

Tantalum Atomic Size

Notes

Atomic Radius

147 pm

Orbital Radius

141.3 pm

Pyykkö Covalent Radius

single bond

146 pm

double bond

126 pm

triple bond

119 pm

Cordero Covalent Radius

170 pm

Shannon-Prewitt Crystal Radius

ion charge: +3, coordination number: 6

86 pm

ion charge: +4, coordination number: 6

82 pm

ion charge: +5

coordination number: 6

78 pm

coordination number: 7

83 pm

coordination number: 8

88 pm

Shannon-Prewitt Effective Ionic Radius

ion charge: +3, coordination number: 6

72 pm

ion charge: +4, coordination number: 6

68 pm

ion charge: +5

coordination number: 6

64 pm

coordination number: 7

69 pm

coordination number: 8

74 pm

Batsanov Crystallographic Van Der Waals Radius

2.2×102 pm

Batsanov Equilibrium Van Der Waals Radius

242 pm

Slater Atomic-Ionic Radius

145 pm

Quantity

Tantalum Crystal Structure

Notes

Nearest Neighbor Distance

300 K, 1 atm

286 pm

Atomic Concentration

300 K, 1 atm

5.55×1022 cm-3

Quantity

Tantalum History

Notes

Discovery

date of discovery

1802

discoverer

Anders Gustaf Ekeberg

birth

January 16, 1767

death

February 11, 1813

location of discovery

Uppsala, Sweden

Origin of Element Name

origin

Tantalus

origin description

mythical—Latin name for the King of Lydia in Greek mythology

Origin of Element Symbol

symbol: Ta

origin

tantalum

origin description

element name

Formerly Used or Proposed Element Names and Symbols

name

tantalium

no matching symbol specified

Quantity

Tantalum Abundances

Notes

Earth's Crust

2.0 ppm

Earth's Mantle

40 ppb

primitive mantle

Bulk Earth

0.025 ppm

Ocean Water

2×10-5 ppm

Metalliferous Ocean Sediment

Basal

2.1 ppm

U.S. Coal

0.22 ppm

Solar System

0.0207

number of atoms for every 106 atoms of silicon

Meteorites

-0.14 ± 0.04

base 10 log of the number of atoms for every 1012 atoms of hydrogen

Quantity

Tantalum Nomenclature

Notes

Element Names in Other Languages

French

tantale

German

Tantal

Italian

tantalio

Spanish

tántalo

Portuguese

tântalo

Anions or Anionic Substituent Groups

tantalide

Cations or Cationic Substituent Groups

tantalum

Ligands

tantalido

Heteroatomic Anion

tantalate

'a' Term—Substitutive Nomenclature

tantala

'y' Term—Chains and Rings Nomenclature

tantaly

References    (Click the button next to a value above to see complete citation information for that entry)

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