Physical Constants

Submitted by ChemPRIME Staff on Thu, 12/09/2010 - 14:35

Physical Constants*

and Sources of Data

Quantity Symbol Traditional Units SI Units
Acceleration of gravity gn 980.665 cm / s2 9.806 65 m / s2
Atomic mass unit (\tfrac{\text{1}}{\text{12}} the mass of 12C atom) amu or u 1.660 538 782(83) ×10-24 g 1.660 538 782(83) × 10-27 kg
Avogadro constant NA, L 6.022 1415 × 1023 particles / mol 6.022 1415 × 1023 particles / mol
Bohr radius ao 0.529 177 210 8 Å 5.291 772 108 × 1011 m
Boltzmann constant k 1.380 650 5×10-16 erg/K 1.380 650 5×10-23 J/K
Charge-to-mass ratio of electron e / m -1.758 820 12× 108 C/g -1.758 820 12× 1011 C/kg
Elementary charge (electron or proton charge) e 1.602 176 53 × 1019 C 1.602 176 53 × 1019 C
Electron rest mass me 9.109 382 6 × 10-28 g 9.109 382 6 × 10-31 kg
Faraday constant F 96 485.3383 C / mol e–

23.06 kcal V– 1 mol–1

96 485.3383 C / mol e–

96 485 J V– 1 mol–1

Gas constant R 0.082 057 L atm mol– 1 K– 1

1.987 cal mol– 1 K– 1

8.314 472(15) dm3Pa mol– 1 K– 1

8.314 472(15) J mol– 1 K– 1

Molar volume (STP) Vm 22.414 L / mol 22.414 × 10– 3 m–3 /mol

22.414 dm3 /mol

Neutron rest mass


mn 1.674 927 28 × 10–24 g

1.008 664 amu

1.674 927 28 × 10–27 kg
Planck’s constant h 6.626 069 3 × 10–27 erg s 6.626 069 3 × 10–34 J s
Proton rest mass mp 1.672 621 71 × 10–24 g

1.007 276 amu

1.672 621 71 × 10–27 kg
Rydberg constant R∞ 3.289 841 960 ×1015 s–1

2.179 871 90 × 10–11 erg

1.097 373 156 8525×107 m–1

2.179 871 90 × 10–18 J

Velocity of light (in a vacuum) c, c0 2.997 924 58 × 1010 cm / s

186 282 mile / s


2.997 924 58 × 108 m/s

*Data from the National Institute for Standards and Technology reference on constants, units, and uncertainty, http://physics.nist.gov/cuu/Constants/index.html.


Online Sources


• Finding Chemical Data in Web and Library Sources. University of Adelaide Library.

http://www.library.adelaide.edu.au/guide/sci/Chemistry/propindex.html


• SIRCh: Selected Internet Resources for Chemistry http://www.indiana.edu/scheminfo/cis_ca.html

SIRCh: Physical PropertyA characteristic of a material that can be measured without changing the material's chemical composition. Information http://www.indiana.edu/scheminfo/ca_ppi.html


• Thermodex. University of Texas at Austin.

http://thermodex.lib.utexas.edu/


• How Many? A Dictionary of Units of Measurement.

http://www.unc.edu/srowlett/units/index.html


Print Sources


• Lide, David R., ed. CRC Handbook of Chemistry and Physics, 89th edition, Boca Raton, FL: CRC Press, 2008-2009.

• Budavari, Susan: O’Neil, Maryadele J.: Smith, Ann: Heckelman, Patricia E., eds. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 13th edition, Rahway, NJ: Merck & Co., 2001.

• Speight, James, ed. Lange’s Handbook of Chemistry, 16th edition, New York: McGraw-Hill, 2004.

• Perry, Robert H., Green, Don W., eds. Perry’s Chemical Engineers Handbook, 7th edition, New York: McGraw-Hill, 1997.

• Zwillinger, Daniel, ed. CRC Standard Mathematical Tables and For- mulae, 30th edition, Boca Raton, FL: CRC Press, 1991.

• Lewis, Richard J., Jr. Hawley’s Condensed Chemical Dictionary

(with CD-ROM), 14th edition, New York: Wiley, 2002.