Numerari from KnowledgeDoor---The scientific calculator with graphing, unit keypads, complex numbers, constants, advanced functions, user-defined keys, quick copy, and
more! Learn more (Link leaves KnowledgeDoor website)

Technetium

Technetium Navigation

Other Elements

By Name

By Symbol

By Number

Quantity

Technetium Quick Reference

Click button to see citations

Notes

Symbol

Tc

Atomic Number

43

Oxidation States

 7

more common with disagreement

 6

less common with disagreement

 5

less common with disagreement

 4

more common

 3

less common

 2

less common

 1

less common

 0

less common

-1

less common

-3

less common

Pauling Electronegativity

1.9

Electron Configuration

Orbital Occupancy

[Kr] 4d5 5s2

[Kr] represents the closed-shell electron configuration of krypton

Orbital Filling Order

[Kr] 5s2 4d5

[Kr] represents the closed-shell electron configuration of krypton

Term Symbol

6S5/2

see expanded configuration ...

Ionization Energies

I   (1)

 7.28 eV

II  (2)

15.26 eV

III (3)

29.54 eV

Electron Affinity

0.55 ± 0.20 eV  

4400 ± 1600 cm-1

Density

liquid, 2430.15 K

10.615 g/ml 

solid, 25 °C

11.000 g/cm3

Molar Volume

solid, 298 K, 1 atm

8.63 cm3/mol

Melting Point

2430.15 K

Boiling Point

1 atm

4538.15 K

Thermal Conductivity

solid

400 K, polycrystalline

50.0 W/(m K)

300 K, polycrystalline

50.7 W/(m K)

298.2 K, polycrystalline

50.7 W/(m K)

273.2 K, polycrystalline

50.9 W/(m K)

extrapolated

see all 10 conductivities ...

Pyykkö Covalent Radius

single bond

128 pm

double bond

120 pm

triple bond

110 pm

Atomic Radius

135 pm

Enthalpy of Fusion

1 atm

23.81 kJ/mol

Enthalpy of Vaporization

1 atm

585.22 kJ/mol

Quantity

Technetium Atomic Structure

Notes

Ionization Energies

I   (1)

 7.28 eV

II  (2)

15.26 eV

III (3)

29.54 eV

Electron Affinity

0.55 ± 0.20 eV  

4400 ± 1600 cm-1

Electron Binding Energies

K    (1s)

21044 eV  

LI   (2s)

 3043 eV  

LII  (2p1/2)

 2793 eV  

LIII (2p3/2)

 2677 eV  

see all 12 energies ...

Electron Configuration

Orbital Occupancy

[Kr] 4d5 5s2

[Kr] represents the closed-shell electron configuration of krypton

Orbital Filling Order

[Kr] 5s2 4d5

[Kr] represents the closed-shell electron configuration of krypton

Term Symbol

6S5/2

see expanded configuration ...

Clementi-Raimondi Effective Nuclear Charge

1s

Orbital Exponent

42.1090

ζ

Principle Quantum Number

1

n

Effective Nuclear Charge

42.1090

Zeff = ζ × n

2s

Orbital Exponent

15.8141

ζ

Principle Quantum Number

2

n

Effective Nuclear Charge

31.6282

Zeff = ζ × n

see all 10 effective nuclear charges ...

Screening Percentage

87.5%

Fluorescence Yields

ωK

0.782

ωL1

0.011

ωL2

0.037

ωL3

0.040

Coster-Kronig Yields

F12

0.10 

F13

0.57 

F23

0.118

Quantity

Technetium Physical Properties

Notes

Density

liquid, 2430.15 K

10.615 g/ml 

solid, 25 °C

11.000 g/cm3

Molar Volume

solid, 298 K, 1 atm

8.63 cm3/mol

Physical Form

hexagonal crystals

Young's Modulus

407.00 GPa

Poisson's Ratio

0.260

Electrical Resistivity

solid, 295 K

14×10-8 Ohm m

Superconducting Transition Temperature

lower purity

7.77 ± 0.02 K

higher purity

7.73 ± 0.02 K

cylindrical single crystals

7.46 ± 0.04 K

prepared by electrodeposition and reduction

7.46 ± 0.05 K

Superconducting Critical Magnetic Field at Absolute Zero

1410×10-4 T

Isothermal Bulk Modulus

300 K

297 GPa

estimated

Isothermal Compressibility

300 K

0.0034 GPa-1

estimated

Quantity

Technetium Atomic Interaction

Notes

Oxidation States

 7

more common with disagreement

 6

less common with disagreement

 5

less common with disagreement

 4

more common

 3

less common

 2

less common

 1

less common

 0

less common

-1

less common

-3

less common

Pauling Electronegativity

1.9

Allred-Rochow Electronegativity

1.36

Configuration Energy

electron volt units

8.94 eV

Pauling units

1.51   

Ghosh-Gupta Electronegativity

3.2244 eV

Nagle Electronegativity

1.30

Cohesive Energy

per mole

661 kJ/mol    

per atom

  6.85 eV/atom

Quantity

Technetium Thermodynamics

Notes

Melting Point

2430.15 K

Boiling Point

1 atm

4538.15 K

Thermal Conductivity

solid

400 K, polycrystalline

50.0 W/(m K)

300 K, polycrystalline

50.7 W/(m K)

298.2 K, polycrystalline

50.7 W/(m K)

273.2 K, polycrystalline

50.9 W/(m K)

extrapolated

see all 10 conductivities ...

Critical Point

11500 K

Vapor Pressure

4621 °C

100 kPa

3961 °C

10 kPa

3453 °C

1 kPa

3051 °C

100 Pa

2725 °C

10 Pa

2454 °C

1 Pa

Enthalpy of Fusion

1 atm

23.81 kJ/mol

Enthalpy of Vaporization

1 atm

585.22 kJ/mol

Electronic Heat Capacity Coefficient

4.30 mJ/(mol K2)

Debye Temperature

Low Temperature Limit ( 0 K )

454 K

Room Temperature ( 298 K )

422 K

Quantity

Technetium Identification

Notes

CAS Number

7440-26-8

Quantity

Technetium Atomic Size

Notes

Atomic Radius

135 pm

Orbital Radius

139.1 pm

Pyykkö Covalent Radius

single bond

128 pm

double bond

120 pm

triple bond

110 pm

Cordero Covalent Radius

147 pm

Shannon-Prewitt Crystal Radius

ion charge: +4, coordination number: 6

78.5 pm

ion charge: +5, coordination number: 6

74 pm  

ion charge: +7

coordination number: 4

51 pm  

coordination number: 6

70 pm  

Shannon-Prewitt Effective Ionic Radius

ion charge: +4, coordination number: 6

64.5 pm

ion charge: +5, coordination number: 6

60 pm  

ion charge: +7

coordination number: 4

37 pm  

coordination number: 6

56 pm  

Batsanov Crystallographic Van Der Waals Radius

205 pm

Batsanov Equilibrium Van Der Waals Radius

237 pm

Slater Atomic-Ionic Radius

135 pm

Quantity

Technetium Crystal Structure

Notes

Nearest Neighbor Distance

300 K, 1 atm

271 pm

Atomic Concentration

300 K, 1 atm

7.04×1022 cm-3

Quantity

Technetium History

Notes

Discovery

date of discovery

1937

discoverer

Emilio Gino Segrè

birth

1905

death

1989

discoverer

Carlo Perrier

birth

1886

death

1948

location of discovery

Palermo, Silicy, Italy

Origin of Element Name

origin

tekhnetos

origin description

property—Greek for artificial

Origin of Element Symbol

symbol: Tc

origin

technetium

origin description

element name

Formerly Used or Proposed Element Names and Symbols

name

trinacrium

no matching symbol specified

name

moseleyum

matching symbol

Ms

name

masurium

matching symbol

Ma

name

moselium

no matching symbol specified

name

neomolybdenum

no matching symbol specified

name

nipponium

matching symbol

Np

name

lucium

no matching symbol specified

name

ekamanganese

matching symbol

Em

name

davyum

matching symbol

Da

name

pelopium

matching symbol

Pe

name

ilmenium

no matching symbol specified

name

polinium

no matching symbol specified

Quantity

Technetium Nomenclature

Notes

Element Names in Other Languages

French

technétium

German

Technetium

Italian

tecneto

Spanish

tecnecio

Portuguese

tecnécio

Anions or Anionic Substituent Groups

technetide

Cations or Cationic Substituent Groups

technetium

Ligands

technetido

Heteroatomic Anion

technetate

'a' Term—Substitutive Nomenclature

techneta

'y' Term—Chains and Rings Nomenclature

technety

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

Andersen, T., H. K. Haugen, and H. Hotop. "Binding Energies in Atomic Negative Ions: III." Journal of Physical and Chemical Reference Data, volume 28, number 6, 1999, pp. 1511–1533.

Batsanov, S. S. "Van der Waals Radii of Elements." Inorganic Materials, volume 37, number 9, 2001, pp. 871–885. See abstract

Campbell, J. L. "Fluorescence Yields and Coster–Kronig Probabilities for the Atomic L Subshells." Atomic Data and Nuclear Data Tables, volume 85, number 2, 2003, pp. 291–315. doi:10.1016/S0092-640X(03)00059-7

Cardarelli, François. Materials Handbook: A Concise Desktop Reference, 2nd edition. London: Springer–Verlag, 2008.

Clementi, E., D. L. Raimondi, and W. P. Reinhardt. "Atomic Screening Constants from SCF Functions. II. Atoms with 37 to 86 Electrons." Journal of Chemical Physics, volume 47, number 4, 1967, pp. 1300–1307. doi:10.1063/1.1712084

Cohen, E. Richard, David R. Lide, and George L. Trigg, editors. AlP Physics Desk Reference, 3rd edition. New York: Springer-Verlag New York, Inc., 2003.

Connelly, Neil G., Ture Damhus, Richard M. Hartshorn, and Alan T. Hutton. Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005. Cambridge: RSC Publishing, 2005.

Cordero, Beatriz, Verónica Gómez, Ana E. Platero-Prats, Marc Revés, Jorge Echeverría, Eduard Cremades, Flavia Barragán, and Santiago Alvarez. "Covalent Radii Revisited." Dalton Transactions, number 21, 2008, pp 2832–2838. doi:10.1039/b801115j

Cox, P. A. The Elements: Their Origin, Abundance and Distribution. Oxford: Oxford University Press, 1989.

de Podesta, Michael. Understanding the Properties of Matter, 2nd edition. London: Taylor & Francis, 2002.

Dronskowski, Richard. Computational Chemistry of Solid State Materials. Weinheim, Germany: WILEY-VCH Verlag GmbH & Co. KGaA, 2005.

Emsley, John. Nature's Building Blocks: An A-Z Guide to the Elements. Oxford: Oxford University Press, 2003.

Emsley, John. The Elements, 3rd edition. Oxford: Oxford University Press, 1998.

Firestone, Richard B. Table of Isotopes, 8th edition, volume 2. Edited by Virginia S. Shirley, with assistant editors Coral M. Baglin, S. Y. Frank Chu, and Jean Zipkin. New York: John Wiley & Sons, Inc., 1996.

Ghosh, Dulal C., and Kartick Gupta. "A New Scale Of Electronegativity Of 54 Elements Of Periodic Table Based On Polarizability Of Atoms." Journal of Theoretical and Computational Chemistry, volume 5, number 4, 2006, pp. 895–911. doi:10.1142/S0219633606002726

Greenwood, N. N., and A. Earnshaw. Chemistry of the Elements, 2nd edition. Oxford: Butterworth-Heinemann, 1997.

Gwyn Williams. Electron Binding Energies. http://www.jlab.org/~gwyn/ebindene.html. Accessed on April 30, 2010.

Ho, C. Y., R. W. Powell, and P. E. Liley. "Thermal Conductivity of the Elements: A Comprehensive Review." Journal of Physical and Chemical Reference Data, volume 3, supplement 1, 1974, pp. I–1 to I–796.

Horvath, A. L. "Critical Temperature of Elements and the Periodic System." Journal of Chemical Education, volume 50, number 5, 1973, pp. 335–336. doi:10.1021/ed050p335

Huheey, James E., Ellen A. Keiter, and Richard L Keiter. Inorganic Chemistry: Principles of Structure and Reactivity, 4th edition. New York: HarperCollins College Publishers, 1993.

Jr., Elbert J. Little,, and Mark M. Jones. "A Complete Table of Electronegativities." Journal of Chemical Education, volume 37, number 5, 1960, pp. 231–233. doi:10.1021/ed037p231

Kittel, Charles. Introduction to Solid State Physics, 8th edition. Hoboken, NJ: John Wiley & Sons, Inc, 2005.

Krause, M. O. "Atomic Radiative and Radiationless Yields for K and L Shells." Journal of Physical and Chemical Reference Data, volume 8, number 2, 1979, pp. 307–327.

Kurakado, Masahiko, Toshiro Takabatake, and Hiromasa Mazaki. "Superconducting Transition Temperature of Technetium and Lead." Bulletin of the Institute for Chemical Research, Kyoto University, volume 55, number 1, 1977, pp. 38–45.

Liboff, Richard L. Introductory Quantum Mechanics, 3rd edition. Reading, MA: Addison Wesley Longman, Inc., 1998.

Lide, David R., editor. CRC Handbook of Chemistry and Physics, 88th edition. Boca Raton, Florida: Taylor & Francis Group, 2008.

Mann, Joseph B., Terry L. Meek, Eugene T. Knight, Joseph F. Capitani, and Leland C. Allen. "Configuration Energies of the d-Block Elements." Journal of the American Chemical Society, volume 122, number 21, 2000, pp. 5132–5137. doi:10.1021/ja9928677

Marshall, James L. Discovery of the Elements: A Search for the Fundamental Principles of the Universe, 2nd edition. Boston, MA: Pearson Custom Publishing, 2002.

Martin, W. C. "Electronic Structure of the Elements." The European Physical Journal C — Particles and Fields, volume 15, number 1–4, 2000, pp. 78–79. doi:10.1007/BF02683401

Miessler, Gary L., and Donald A. Tarr. Inorganic Chemistry, 3rd edition. Upper Saddle River, NJ: Pearson Prentice Hall, 2004.

Moore, Charlotte E. Ionization Potentials and Ionization Limits Derived from the Analyses of Optical Spectra. Washington, D.C.: National Bureau of Standards, 1970.

Nagle, Jeffrey K. "Atomic Polarizability and Electronegativity." Journal of the American Chemical Society, volume 112, number 12, 1990, pp. 4741–4747. doi:10.1021/ja00168a019

Oxtoby, David W., H. P. Gillis, and Alan Campion. Principles of Modern Chemistry, 6th edition. Belmont, CA: Thomson Brooks/Cole, 2008.

Pauling, Linus. The Nature of the Chemical Bond, 3rd edition. Ithaca, NY: Cornell University Press, 1960.

Pekka Pyykkö. Self-Consistent, Year-2009 Covalent Radii. http://www.chem.helsinki.fi/~pyykko/Radii09.pdf. Accessed on November 20, 2010.

Perrier, C., and E. Segrè. "Some Chemical Properties of Element 43." Journal of Chemical Physics, volume 5, number 9, 1937, pp. 712–716. doi:10.1063/1.1750105

Pyykkö, Pekka, and Michiko Atsumi. "Molecular Double-Bond Covalent Radii for Elements Li-E112." Chemistry - A European Journal, volume 15, number 46, 2009, pp. 12770–12779. doi:10.1002/chem.200901472

Pyykkö, Pekka, and Michiko Atsumi. "Molecular Single-Bond Covalent Radii for Elements 1-118." Chemistry - A European Journal, volume 15, number 1, 2009, pp. 186–197. doi:10.1002/chem.200800987

Pyykkö, Pekka, Sebastian Riedel, and Michael Patzschke. "Triple-Bond Covalent Radii." Chemistry - A European Journal, volume 11, number 12, 2005, pp. 3511–3520. doi:10.1002/chem.200401299

Sansonetti, J. E., and W. C. Martin. "Handbook of Basic Atomic Spectroscopic Data." Journal Of Physical And Chemical Reference Data, volume 34, number 4, 2005, pp. 1559–2259. doi:10.1063/1.1800011

Schwochau, Klaus. Technetium Chemistry and Radiopharmaceutical Applications. Weinheim, Germany: WILEY-VCH Verlag GmbH, 2000.

Sekula, S. T., R. H. Kernohan, and G. R. Love. "Superconducting Properties of Technetium." Physical Review, volume 155, number 2, 1967, pp. 364–369. doi:10.1103/PhysRev.155.364

Shannon, R. D. "Revised Effective Ionic Radii and Systematic Studies of Interatomic Distances in Halides and Chalcogenides." Acta Crystallographica Section A, volume 32, number 5, 1976, pp. 751–767. doi:10.1107/S0567739476001551

Silbey, Robert J., Robert A. Alberty, and Moungi G. Bawendi. Physical Chemistry, 4th edition. Hoboken, NJ: John Wiley & Sons, Inc., 2005.

Singman, Charles N. "Atomic Volume and Allotropy of the Elements." Journal of Chemical Education, volume 61, number 2, 1984, pp. 137–142. doi:10.1021/ed061p137

Slater, J. C. "Atomic Radii in Crystals." The Journal of Chemical Physics, volume 41, number 10, 1964, pp. 3199–3204. doi:10.1063/1.1725697

Smith, Derek W. Inorganic Substances: A Prelude to the Study of Descriptive Inorganic Chemistry. Cambridge: Cambridge University Press, 1990.

Soukhanov, Anne H., editor. The American Heritage Dictionary Of The English Language, 3rd edition. Boston: Houghton Mifflin Company, 1992.

Stewart, G. R. "Measurement of low-temperature specific heat." Review of Scientific Instruments, volume 54, number 1, 1983, pp. 1–11. doi:10.1063/1.1137207

Stewart, G. R. "Measurement of Low-Temperature Specific Heat." Review of Scientific Instruments, volume 54, number 1, 1983, pp. 1–11. doi:10.1063/1.1137207

Tari, A. The Specific Heat of Matter at Low Temperatures. London: Imperial College Press, 2003.

Vainshtein, Boris K., Vladimir M. Fridkin, and Vladimir L. Indenbom. Structure of Crystals, 2nd edition. Modern Crystallography 2. Edited by Boris K. Vainshtein, A. A. Chernov, and L. A. Shuvalov. Berlin: Springer-Verlag, 1995.

Waber, J. T., and Don T. Cromer. "Orbital Radii of Atoms and Ions." Journal of Chemical Physics, volume 42, number 12, 1965, pp. 4116–4123. doi:10.1063/1.1695904

Waldron, Kimberley A., Erin M. Fehringer, Amy E. Streeb, Jennifer E. Trosky, and Joshua J. Pearson. "Screening Percentages Based on Slater Effective Nuclear Charge as a Versatile Tool for Teaching Periodic Trends." Journal of Chemical Education, volume 78, number 5, 2001, pp. 635–639. doi:10.1021/ed078p635

Weeks, Mary Elvira, and Henry M. Leicester. Discovery of the Elements, 7th edition. Easton, PA: Journal of Chemical Education, 1968.

Yaws, Carl L. "Liquid Density of the Elements." Chemical Engineering, volume 114, number 12, 2007, pp. 44–46.

Yaws, Carl L. The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals. Houston, TX: Gulf Publishing Company, 2005.

Heaven's Boulevard astronomical sky image for any location, date, and time. Personalize with a picture and message. Great gift for birthdays, anniversaries, or any special event. Learn more (Link leaves KnowledgeDoor website)