# Template:Base quantities and count

From Bioblast

Quantity Symbol for quantity *Q*Symbol for dimension Name of abstract unit *u*_{Q}Symbol for unit *u*_{Q}[*]elementary entity ^{*,$}*U*_{X}U elementary unit x count ^{*,$}*N*_{X}=*N*Β·*U*_{X}X elementary unit x amount of substance ^{*,Β§}*n*_{X}=*N*_{X}Β·*N*_{A}^{-1}N mole mol charge ^{*,β¬}*Q*_{el}=*z*_{X}Β·*e*Β·*N*_{X}IΒ·T coulomb C = AΒ·s length *l*L meter m mass *m*M kilogram kg time *t*T second s electric current *I*I ampere A thermodynamic temperature *T*Ξ kelvin K luminous intensity *I*_{v}J candela cd

- [*] SI units, except for the canonical 'elementary unit' [x]. The following footnotes are canonical comments, related to iconic symbols.
^{*}For the elementary quantities*N*_{X},*n*_{X}, and*Q*_{el}, the entity-type*X*of the elementary entity*U*_{X}has to be specified in the text and indicated by a subscript:*n*_{O2};*N*_{ce};*Q*_{el}.^{$}Count*N*_{X}equals the number of elementary entities*U*_{X}. In the SI, the quantity 'count' is explicitly considered as an exception: "Each of the seven base quantities used in the SI is regarded as having its own dimension. .. All other quantities, with the exception of counts, are derived quantities" (Bureau International des Poids et Mesures 2019 The International System of Units (SI)). An elementary entity*U*_{X}is a material unit, it is not a count (*U*_{X}is not a number of*U*_{X}).*N*_{X}has the dimension X of a count and*U*_{X}has the dimension U of an elementary entity; both quantities have the same abstract unit, the 'elementary unit' [x].^{Β§}Amount*n*_{X}is an elementary quantity, converting the elementary unit [x] into the SI base unit mole [mol] using the Avogadro constant*N*_{A}.^{β¬}Charge is a derived SI quantity. Charge is an elementary quantity, converting the elementary unit [x] into coulombs [C] using the elementary charge*e*, or converting moles [mol] into coulombs [C] using the Faraday constant*F*.*z*_{X}is the charge number per elementary entity*U*_{X}, which is a constant for any defined elementary entity*U*_{X}.*Q*_{el}=*z*_{X}Β·*F*Β·*n*_{X}