Nature of Light: The Photon
The photon is recognized as the fundamental particle of light, encapsulating the concept of light having both wave-like and particle-like properties. This duality is illustrated through experimental evidence, particularly the Compton scattering experiment, which demonstrated that light can collide with electrons, transferring energy and momentum as if it were a particle. The energy of a photon is directly related to its frequency (E = hn), where 'h' is Planck's constant, while its momentum is defined as p = hn/c.
As such, all photons of a particular frequency share the same energy and momentum, regardless of the intensity of light. Increasing the intensity results in more photons being emitted, but does not affect the energy of individual photons, substantiating the conclusion that photons are distinct entities capable of exhibiting both particle and wave behaviors depending on the context of the experiment. This understanding aligns with the descriptions of both electromagnetic radiation and matter, further solidified by the work of scientists like Albert Einstein and Louis de Broglie.