12.1 : 电磁 (EM) 辐射的双重性质

Electromagnetic radiation can be considered as an electromagnetic wave propagating through space and as energy-containing particles called photons.

Electromagnetic radiation is characterized by its frequency, which is the number of repeating waves that pass a given point in a fixed time. At the same time, it interacts with matter and transfers a set amount of energy, like a particle.

The energy of a photon is proportional to the frequency of the radiation, expressed by the Planck equation. The set of radiation with all possible frequencies is known as the electromagnetic spectrum.

The electromagnetic spectrum can also be divided into wavelength ranges, which are the distances between consecutive peaks or troughs in the wave.

Wavelength and frequency are related to the velocity of the radiation through a medium, which is approximated as the speed of light in a vacuum.

The frequency and wavelength are inversely related to each other, so the higher the frequency, the lower the wavelength.