What is a photon?

A photon is best defined as a particle of light energy. In physics, photons are considered the fundamental particles that make up light and other forms of electromagnetic radiation. They exhibit both wave-like and particle-like properties, but describing a photon as a particle emphasizes its role in transmitting energy through space.

Photons carry quantized energy, which means that their energy is directly proportional to their frequency. This relationship is key in various phenomena, such as the photoelectric effect and the behavior of light in quantum mechanics. While photons do have wave properties, describing them primarily as particles allows us to understand how they interact with matter, such as in absorption and emission processes in atoms.

Understanding that photons are particles rather than waves or sound also clarifies their distinction from other forms of energy, like sound waves, which are mechanical and require a medium to propagate. Similarly, they are not categorized as chemical energy, which pertains to the energy stored in the bonds of chemical compounds. Thus, defining a photon as a particle of light energy accurately reflects its nature in the context of physics.