Template:Base quantities and count: Difference between revisions
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| thermodynamic temperature || ''T'' || ฮ || kelvin || K | | thermodynamic temperature || ''T'' || ฮ || kelvin || K | ||
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| amount of substance || ''n'' || N || mole || mol | | [[amount]] of substance<sup>*</sup> || ''n'' || N || mole || mol | ||
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| luminous intensity || ''I''<sub>v</sub> || J || candela || cd | | luminous intensity || ''I''<sub>v</sub> || J || candela || cd | ||
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| count; [[number of entities]]* || ''N'' | | count; [[number of entities]]<sup>*,#</sup> || ''N'' || C || counting unit || x | ||
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:::: * 'Count' is synonymous with 'number of entities' and is one of the most fundamental quantities in physics, but the name, symbol and unit are not included in the SI as a base quantity or base unit. An 'entity' is a countable object or event. 'Number of entities' and 'number' are | :::: <sup>*</sup> For the quantities ''n'' and ''N'', the entities X have to be specified and should always be indicated by a subscript or in parentheses (IUPAC). | ||
:::: <sup>#</sup> 'Count' is synonymous with 'number of entities' and is one of the most fundamental quantities in physics, but the name, symbol and unit are not included in the SI as a base quantity or base unit. Not all sample types contain countable objects. An 'entity', X, is a countable object or event. Countable objects are particles, such as electrons, molecules, packaging units (parcels), cells, organisms, individuals, patients. 'Number of entities' and 'number' are distinguished (in German: Anzahl ''versus'' Zahl). The count is not a pure dimensionless number, but the dimension of the count, C, is the entity. The magnitude of a count, ''N'', is expressed by a pure number times the 'counting unit' [x], indicating how many times different members of the defined entity are ''accounted'' for in a defined system (not how many times the same member of the defined entity is re-counted in the system โ consider the political problem in counting votes), or how many times a defined event is counted during a defined period of time. ''N'' [x] is the count, and ''N''/''t'' [xยทs<sup>-1</sup>] is the frequency (counts per time in units of counting units per second). |
Revision as of 18:46, 15 May 2020
Base quantity Symbol for quantity Symbol for dimension Name of SI unit Symbol for SI unit length l L meter m mass m M kilogram kg time t T second s electric current I I ampere A thermodynamic temperature T ฮ kelvin K amount of substance* n N mole mol luminous intensity Iv J candela cd count; number of entities*,# N C counting unit x
- * For the quantities n and N, the entities X have to be specified and should always be indicated by a subscript or in parentheses (IUPAC).
- # 'Count' is synonymous with 'number of entities' and is one of the most fundamental quantities in physics, but the name, symbol and unit are not included in the SI as a base quantity or base unit. Not all sample types contain countable objects. An 'entity', X, is a countable object or event. Countable objects are particles, such as electrons, molecules, packaging units (parcels), cells, organisms, individuals, patients. 'Number of entities' and 'number' are distinguished (in German: Anzahl versus Zahl). The count is not a pure dimensionless number, but the dimension of the count, C, is the entity. The magnitude of a count, N, is expressed by a pure number times the 'counting unit' [x], indicating how many times different members of the defined entity are accounted for in a defined system (not how many times the same member of the defined entity is re-counted in the system โ consider the political problem in counting votes), or how many times a defined event is counted during a defined period of time. N [x] is the count, and N/t [xยทs-1] is the frequency (counts per time in units of counting units per second).