Nominal mass: Difference between revisions
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== Related Terms == | == Related Terms == | ||
[[Mass]] | *[[Mass]] | ||
== External Links == | == External Links == | ||
[http://www.spectroscopynow.com/Spy/basehtml/SpyH/1,1181,4-14-6-0-0-education_dets-0-2585,00.html Base Peak Glossary] | *[http://www.spectroscopynow.com/Spy/basehtml/SpyH/1,1181,4-14-6-0-0-education_dets-0-2585,00.html Base Peak Glossary] | ||
:The mass of an ion containing the most abundant isotopes, calculated with nominal atomic weights.?????????????? | :The mass of an ion containing the most abundant isotopes, calculated with nominal atomic weights.?????????????? | ||
[http://www.rzuser.uni-heidelberg.de/~bl5/ency/ency.html Little Encyclopedia of MS] | *[http://www.rzuser.uni-heidelberg.de/~bl5/ency/ency.html Little Encyclopedia of MS] | ||
:The nominal mass of an ion is calculated by simply adding the integer masses of the lightest isotopes of all elements contributing to the molecule, e.g. to calculate the nominal mass of CH<sub>3</sub>Br you have to use the nominal masses of <sup>12</sup>C, <sup>1</sup>H, and <sup>79</sup>Br to obtain M<sub>nomi</sub> = 94 [[amu]] | :The nominal mass of an ion is calculated by simply adding the integer masses of the lightest isotopes of all elements contributing to the molecule, e.g. to calculate the nominal mass of CH<sub>3</sub>Br you have to use the nominal masses of <sup>12</sup>C, <sup>1</sup>H, and <sup>79</sup>Br to obtain M<sub>nomi</sub> = 94 [[amu]] | ||
[http://www1.shimadzu.com/products/lab/mass/a.html Shimadzu Mass Spectrometry Glossary] | *[http://www1.shimadzu.com/products/lab/mass/a.html Shimadzu Mass Spectrometry Glossary] | ||
:Same meaning as [[mass number]] (Nearest integer when expressing the mass of an atom in units that define <sup>12</sup>C as 12. The number is approximately the sum of protons and neutrons in the atomic nucleus. In mass analysis the [[mass number]] is the sum of the masses of the atoms making up an ion or other particle (<sup>12</sup>C = 12, <sup>1</sup>H = 1, <sup>16</sup>O = 16, <sup>14</sup>N = 14...)) | :Same meaning as [[mass number]] (Nearest integer when expressing the mass of an atom in units that define <sup>12</sup>C as 12. The number is approximately the sum of protons and neutrons in the atomic nucleus. In mass analysis the [[mass number]] is the sum of the masses of the atoms making up an ion or other particle (<sup>12</sup>C = 12, <sup>1</sup>H = 1, <sup>16</sup>O = 16, <sup>14</sup>N = 14...)) | ||
[[Category:Mass]] | [[Category:Mass]] | ||
Revision as of 16:58, 30 November 2005
| DRAFT DEFINITION |
| Nominal mass |
|---|
| The mass of an ion or molecule calculated using the mass of the most abundant isotope of each element. |
| Considered between 2004 and 2006 but not included in the 2006 PAC submission |
| This is an unofficial draft definition presented for information and comment. |
| See proposed definition on the Nominal mass discussion page. |
Related Terms
External Links
- The mass of an ion containing the most abundant isotopes, calculated with nominal atomic weights.??????????????
- The nominal mass of an ion is calculated by simply adding the integer masses of the lightest isotopes of all elements contributing to the molecule, e.g. to calculate the nominal mass of CH3Br you have to use the nominal masses of 12C, 1H, and 79Br to obtain Mnomi = 94 amu
- Same meaning as mass number (Nearest integer when expressing the mass of an atom in units that define 12C as 12. The number is approximately the sum of protons and neutrons in the atomic nucleus. In mass analysis the mass number is the sum of the masses of the atoms making up an ion or other particle (12C = 12, 1H = 1, 16O = 16, 14N = 14...))
