Editing Reflectance (section)

{{short description|Capacity of an object to reflect light}}
[[File:Image-Metal-reflectance.png|thumb|400px|Spectral reflectance curves for [[aluminium]] (Al), [[silver]] (Ag), and [[gold]] (Au) metal [[mirror]]s at normal incidence]]

The '''reflectance''' of the surface of a [[material]] is its effectiveness in [[Reflection (physics)|reflect]]ing [[radiant energy]]. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the [[electronic structure]] of the material to the electromagnetic field of light, and is in general a function of the frequency, or [[wavelength]], of the light, its polarization, and the [[angle of incidence (optics)|angle of incidence]]. The dependence of reflectance on the wavelength is called a ''reflectance spectrum'' or ''spectral reflectance curve''.