Difference between revisions of "Electron mass"
Physchim62 (talk | contribs) (Created page with 'The '''electron mass''' or '''electron rest mass''' (symbol: '''''m''<sub>e</sub>''') is a fundamental physical constant. It can be expressed in kilograms, in which case it i…') |
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:''m''<sub>e</sub> = 9.109 382 15(45) kg | :''m''<sub>e</sub> = 9.109 382 15(45) kg | ||
:''A''<sub>r</sub>(e) = 5.485 799 0943(23){{e|−4}} | :''A''<sub>r</sub>(e) = 5.485 799 0943(23){{e|−4}} | ||
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| + | ==Electron relative atomic mass== | ||
| + | The electron relative atomic mass, ''A''<sub>r</sub>(e), is measured by comparing the [[Cyclotron frequency|cyclotron frequencies]] of [[electron]]s and <sup>12</sup>C<sup>6+</sup> ions confined in a [[Penning trap]].<ref>{{citation | first1 = Dean L. | last1 = Farnham | first2 = Robert S., Jr. | last2 = Van Dyck | first3 = Paul B. | last3 = Schwinberg | title = Determination of the Electron's Atomic Mass and the Proton/Electron Mass Ratio via Penning Trap Mass Spectroscopy | journal = Phys. Rev. Lett. | volume = 75 | issue = 20 | pages = 3598–3601 | year = 1995 | doi = 10.1103/PhysRevLett.75.3598}}.</ref> | ||
==Notes and references== | ==Notes and references== | ||
Revision as of 09:47, 23 August 2010
The electron mass or electron rest mass (symbol: me) is a fundamental physical constant. It can be expressed in kilograms, in which case it is determined by the measurement of other physical constants, or as the electron relative atomic mass (symbol: Ar(e)), the mass ratio of the electron mass to one-twelfth of the mass of a carbon-12 atom, which can be measured almost directly. The 2006 CODATA recommended values are:[1]
- me = 9.109 382 15(45) kg
- Ar(e) = 5.485 799 0943(23) × 10−4
Electron relative atomic mass
The electron relative atomic mass, Ar(e), is measured by comparing the cyclotron frequencies of electrons and 12C6+ ions confined in a Penning trap.[2]
Notes and references
Notes
References
- ↑ Mohr, Peter J.; Taylor, Barry N.; Newell, David B. CODATA Recommended Values of the Fundamental Physical Constants: 2006. Rev. Mod. Phys. 2008, 80 (2), 633–730. doi:10.1103/RevModPhys.80.633, <http://physics.nist.gov/cuu/Constants/codata.pdf>.
- ↑ Farnham, Dean L.; Van Dyck, Robert S., Jr.; Schwinberg, Paul B. Determination of the Electron's Atomic Mass and the Proton/Electron Mass Ratio via Penning Trap Mass Spectroscopy. Phys. Rev. Lett. 1995, 75 (20), 3598–3601. DOI: 10.1103/PhysRevLett.75.3598.
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