- For a given physical phenomenon, such as electromagnetic radiation, the smallest quantity, such as that of energy, that can exist independently. For such phenomena, any quantity above this can only exist in multiples of this unit. In the case of light, for, instance, energy can be absorbed or radiated only in multiples of these discrete packages called photons.
- A quantum (1) utilized as a unit. For example, the quantum of electromagnetic radiation is the photon, which is also called light quantum.
- Any given quantity which can be counted or measured.
- synonymquantized value
- One of the finite values derived from a quantity or phenomenon with an infinitely variable range of values, through the process of quantization (1). Also called quantum (2).