Concentration total amount of all "other" constituents in a mixture: If formula_6 is much smaller than formula_26, the mole ratio is almost identical to the mole fraction. The SI unit is mol/mol. However, the deprecated parts-per notation is often used to describe small mole ratios. The mass fraction formula_33 is the fraction of one substance with mass formula_2 to the mass of the total mixture formula_35, defined as: The SI unit is kg/kg. However, the deprecated parts-per notation is often used to describe small mass fractions. The mass ratio formula_37 is defined as the mass of a constituent formula_2 divided by
Flick (physics) Flick (physics) In optical engineering and telecommunications engineering, the flick is a unit of spectral radiance. One flick corresponds to a spectral radiance of 1 watt per steradian per square centimeter of surface per micrometer of span in wavelength (W·sr·cm·μm). This is equivalent to 10 watts per steradian per cubic meter (W·sr·m). In practice, spectral radiance is typically measured in microflicks (10 flicks). One microflick is equivalent to 10 kilowatts per steradian per cubic meter (kW·sr·m). In radio astronomy, the unit flik was coined by a group at Lockheed in Palo Alto, California as a substitute for the SI derived