calcium

• Formula: Ca
• Molecular weight: 40.078
• IUPAC Standard InChI: InChI=1S/Ca Copy

  
• IUPAC Standard InChIKey: OYPRJOBELJOOCE-UHFFFAOYSA-N Copy
• CAS Registry Number: 7440-70-2
• Chemical structure:
  This structure is also available as a 2d Mol file
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• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
• Data at other public NIST sites:
  • NIST Atomic Spectra Database - Lines Holdings (on physics web site)
  • NIST Atomic Spectra Database - Levels Holdings (on physics web site)
  • NIST Atomic Spectra Database - Ground states and ionization energies (on physics web site)
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data

Go To: Top, Phase change data, Gas phase ion energetics data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Phase change data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Gas phase ion energetics data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

View reactions leading to Ca⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Honig and Kramer, 1969
Honig, R.E.; Kramer, D.A., Vapor pressure data for the solid and liquid elements, RCA Rev., 1969, 1969, 285. [all data]

Hartmann and Schneider, 1929
Hartmann, H.; Schneider, R., Die Siedetemperaturen von Magnesium, Calcium, Strontium, Barium and Lithium, Z. Anorg. Allg. Chem., 1929, 180, 1, 275-283, https://doi.org/10.1002/zaac.19291800129 . [all data]

Petrunin, Andersen, et al., 1996
Petrunin, V.V.; Andersen, H.H.; Balling, P.; Andersen, T., Structural Properties of the Negative Calcium Ion: Binding Energies and Fine-structure Splitting, Phys. Rev. Lett., 1996, 76, 5, 744, https://doi.org/10.1103/PhysRevLett.76.744 . [all data]

Walter and Peterson, 1992
Walter, C.W.; Peterson, J.R., Shape Resonance in Ca- Photodetachment and the Electron Affinity of Ca(1S), Phys. Rev. Lett., 1992, 68, 15, 2281, https://doi.org/10.1103/PhysRevLett.68.2281 . [all data]

Nadeau, Zhao, et al., 1992
Nadeau, M.J.; Zhao, X.L.; Garwan, M.A.; Litherland, A.E., Ca Negative-Ion Binding Energy, Phys. Rev. A, 1992, 46, 7, R3588, https://doi.org/10.1103/PhysRevA.46.R3588 . [all data]

Pegg, Thompson, et al., 1987
Pegg, D.J.; Thompson, J.S.; Compton, R.N.; Alton, G.D., Evidence for a Stable Negative Ion of Calcium, Phys. Rev. Lett., 1987, 59, 20, 2267, https://doi.org/10.1103/PhysRevLett.59.2267 . [all data]

Lide, 1992
Lide, D.R. (Editor), Ionization potentials of atoms and atomic ions in Handbook of Chem. and Phys., 1992, 10-211. [all data]

Lau and Hildenbrand, 1990
Lau, K.H.; Hildenbrand, D.L., High-temperature equilibrium studies of the gaseous thorium chlorides, J. Chem. Phys., 1990, 92, 6124. [all data]

Kelly, 1987
Kelly, R.L., Atomic and ionic spectrum lines of hydrogen through kryton, J. Phys. Chem. Ref. Data, 1987, 16. [all data]

Sugar and Corliss, 1985
Sugar, J.; Corliss, C., Atomic energy levels of the iron period elements: Potassium through nickel, J. Phys. Chem. Ref. Data, 1985, 14. [all data]

Rauh and Ackermann, 1979
Rauh, E.G.; Ackermann, R.J., The first ionization potentials of the transition metals, J. Chem. Phys., 1979, 70, 1004. [all data]

Kleinschmidt and Hildenbrand, 1978
Kleinschmidt, P.D.; Hildenbrand, D.L., Dissociation energies of CaI, SrI, and BaI from high temperature mass spectrometry, J. Chem. Phys., 1978, 68, 2819. [all data]

Rauh and Ackermann, 1974
Rauh, E.G.; Ackermann, R.J., First ionization potentials of some refractory oxide vapors, J. Chem. Phys., 1974, 60, 1396. [all data]

Brown, Tilford, et al., 1973
Brown, C.M.; Tilford, S.G.; Ginter, M.L., Absorption spectrum of Ca I in the 1580-2090A region, J. Opt. Soc. Am., 1973, 63, 1454. [all data]

Okudaira, 1970
Okudaira, S., Multiple ionization of Ca, Sr and Ba by electron impact, J. Phys. Soc. Jpn., 1970, 29, 409. [all data]

Moore, 1970
Moore, C.E., Ionization potentials and ionization limits derived from the analyses of optical spectra, Natl. Stand. Ref. Data Ser., (U.S. Natl. Bur. Stand.), 1970, 34, 1. [all data]

Risberg, 1968
Risberg, G., The spectrum of atomic calcium, Ca I, and extensions to the analysis of Ca II, Ark. Fys., 1968, 37, 231. [all data]

Zinkiewicz, 1553
Zinkiewicz, J.M., Determination of the ionization potential of Ca and Mg atoms by the surface ionization method using a mass spectrometer, Proc. Colloq. Spectros. Intern., 14th Debrecen, Hung., 1967,, 1553, 3. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  Tboil	Boiling point
  Ttriple	Triple point temperature
  ΔfH°gas	Enthalpy of formation of gas at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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