In its mathematical definition, what value signifies a perfect reflector that bounces back every photon it receives?

Answer

1

Albedo is expressed as a ratio between 0 and 1, or 0% to 100%. A value of 1 signifies a perfect reflector that reflects all incident solar radiation.

In its mathematical definition, what value signifies a perfect reflector that bounces back every photon it receives?
Earthsurfacereflectivity