Periodic Table/Tantalum
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73Ta180.9479 Da

Tantalum

Transition Metal·Period 6, Group 5·s-block

Heavy blue-grey metallic transition element. Ta-181 is a stable isotope, and Ta-180 is a radioactive isotope, with a half-life in excess of 10^7 years. Used in surgery as it is unreactive. Forms a passive oxide layer in air. Identified in 1802 by Ekeberg and isolated in 1820 by Jons J. Berzelius.

Gallery

Piece of tantalum, 1 cm in size

Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/tantalum.php

Bohr model of Tantalum
Emission spectrum of Tantalum

Emission spectrum

Physical Propertiesmass · density · phase · crystal

Atomic Mass

180.9479Da

Density

16.4000g/cm³

Phase (STP)

Solid

Melting Point

3290.2K

Boiling Point

5728.1K

Molar Heat

0.1400J/(mol·K)

Crystal Structure

BCC

Lattice Constant

3.310Å

Atomic Radiiatomic · covalent · van der Waals

Atomic (Empirical)

145.00pm

Covalent

146.00pm

Van der Waals

222.00pm

Electronic Propertieselectronegativity · ionization · affinity

Electron Configuration

[Xe] 4f14 5d3 6s2

Electron Shells

2, 8, 18, 32, 11, 2

Electronegativity

1.50Pauling

Electron Affinity

0.3kJ/mol

1st Ionization Energy

7.5kJ/mol

Oxidation States

-3, -1, +1, +2, +3, +4, +5

Orbital DiagramAufbau · Hund's rule · Pauli exclusion

↑↓
1s2
↑↓
2s2
↑↓
↑↓
↑↓
2p6
↑↓
3s2
↑↓
↑↓
↑↓
3p6
↑↓
↑↓
↑↓
↑↓
↑↓
3d10
↑↓
4s2
↑↓
↑↓
↑↓
4p6
↑↓
↑↓
↑↓
↑↓
↑↓
4d10
↑↓
5s2
↑↓
↑↓
↑↓
5p6
↑↓
↑↓
↑↓
↑↓
↑↓
↑↓
↑↓
4f14
↑
↑
↑
5d3
↑↓
6s2

Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d3 6s2Short: [Xe] 4f14 5d3 6s2

Ionization Energies (73 known)

1st7.5 kJ/mol2nd16.2 kJ/mol3rd23.1 kJ/mol4th35.0 kJ/mol5th48.3 kJ/mol6th94.0 kJ/mol7th119.0 kJ/mol8th139.0 kJ/mol9th159.0 kJ/mol10th180.0 kJ/mol11th213.0 kJ/mol12th235.0 kJ/mol13th262.0 kJ/mol14th304.0 kJ/mol15th338.0 kJ/mol16th363.0 kJ/mol17th396.0 kJ/mol18th439.0 kJ/mol19th482.0 kJ/mol20th530.0 kJ/mol21th570.0 kJ/mol22th610.0 kJ/mol23th660.0 kJ/mol24th700.0 kJ/mol25th750.0 kJ/mol26th790.0 kJ/mol27th832.0 kJ/mol28th1064.0 kJ/mol29th1110.0 kJ/mol30th1160.0 kJ/mol31th1211.0 kJ/mol32th1262.0 kJ/mol33th1313.0 kJ/mol34th1382.0 kJ/mol35th1434.0 kJ/mol36th1490.0 kJ/mol37th1542.0 kJ/mol38th1748.0 kJ/mol39th1799.0 kJ/mol40th1857.0 kJ/mol41th1910.0 kJ/mol42th2053.0 kJ/mol43th2113.0 kJ/mol44th2254.0 kJ/mol45th2314.7 kJ/mol46th3898.7 kJ/mol47th4014.0 kJ/mol48th4143.0 kJ/mol49th4278.0 kJ/mol50th4410.0 kJ/mol51th4537.0 kJ/mol52th4745.0 kJ/mol53th4877.0 kJ/mol54th5024.0 kJ/mol55th5159.0 kJ/mol56th5537.0 kJ/mol57th5655.0 kJ/mol58th5785.0 kJ/mol59th5907.0 kJ/mol60th6364.0 kJ/mol61th6502.0 kJ/mol62th6769.0 kJ/mol63th6900.0 kJ/mol64th15137.0 kJ/mol65th15461.0 kJ/mol66th15820.0 kJ/mol67th16150.0 kJ/mol68th17840.0 kJ/mol69th18250.0 kJ/mol70th18760.0 kJ/mol71th19088.5 kJ/mol72th76852.0 kJ/mol73th78394.6 kJ/molSuccessive Ionization Energies

Emission Spectrumvisible range · characteristic spectral lines

474
481
405
Ta emission
380nm750nm
404.6 nm(100%)474.0 nm(50%)481.3 nm(40%)

Abundanceby mass

🌍Earth's Crust
2.0 ppm
🌊Ocean
2.0 ppt
✨Universe
80.0 ppt
🧬Human Body—

Log scale · ppm = parts per million by mass

Biological Role

No biological role

No known biological role. Biocompatible; used in surgical implants.

Discovery

Discovered By

Anders Ekeberg

Named By

—

Year

1802

Nuclear Data

Known Isotopes

40

Stable Isotopes

1

Stable Mass Numbers

181

Natural isotopic abundance (IUPAC recommended values)

Isotopes of Ta40 known

NuclideZNMass (AMU)Half-lifeDecayJπAbundance
155Ta7382154.9742483.20 msp (1%)11/2-—
156Ta7383155.972087106 msp (0.71%), β⁺ (0.29%)2-—
157Ta7384156.96822710.1 msα (0.966%), p (0.034%), β⁺1/2+—
181Tastable73108180.947999Stablestable (1%)7/2+9998.7990%
192Ta73119191.9752012.20 sβ⁻ (1%), β⁻n2—
193Ta73120192.977660Unknownβ⁻, β⁻n7/2+—
194Ta73121193.981610Unknownβ⁻, β⁻n——

Click any isotope for its full page with decay chain:

155Ta156Ta157Ta158Ta159Ta160Ta161Ta162Ta163Ta164Ta165Ta166Ta167Ta168Ta169Ta170Ta171Ta172Ta173Ta174Ta175Ta176Ta177Ta178Ta179Ta180Ta181Ta182Ta183Ta184Ta185Ta186Ta187Ta188Ta189Ta190Ta191Ta192Ta193Ta194Ta
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