mole is the si unit that expresses the amount of substance.
mole is the si unit that expresses the amount of substance.
the is the si unit that expresses the amount of substance?
mole
the gas constant occurs in the ideal gas law, as follows:









































where "p" is the absolute pressure (si unit pascals), "v" is the volume of gas (si unit cubic metres), "n" is the amount of gas (si unit moles), "m" is the mass (si unit kilograms) contained in "v", and "t" is the thermodynamic temperature (si unit kelvins). "r" is the molar-weight-specific gas constant, discussed below. the gas constant is expressed in the same physical units as molar entropy and molar heat capacity.









































section::::dimensions.









































from the ideal gas law "pv" = "nrt" we get:
gas constant
where formula_2 is the spectral irradiance, formula_3 is the radiant flux of the source (si unit: watt, w) within a wavelength interval formula_4 (si unit: meter, m), incident on the surface area, formula_5 (si unit: square meter,m²). the si unit for spectral irradiance is w/m. however it is often more useful to measure area in terms of centimeters and wavelength in nanometers, thus submultiples of the si units of spectral irradiance will be used, for example μw/cm*nm
spectroradiometer