What are the electromagnetic spectrum

Release time: 2021-11-04

(1) Radio waves - the wavelength is from a few thousand meters to about 0.3 meters, and the general TV and radio broadcasting bands use this wave;

(2) Microwave - the wavelength is from 0.3 meters to 10^-3 meters, these waves are mostly used in radar or other communication systems;

(3) Infrared rays - the wavelength is from 10^-3 meters to 7.8×10^-7 meters;

(4) Visible light - this is a very narrow band of light that people can perceive. The wavelength is from 780-380nm. Light is an electromagnetic wave emitted when the state of motion of electrons in atoms or molecules changes. Because it is the part of electromagnetic waves that we can directly feel and perceive very little;

(5) Ultraviolet rays - wavelengths from 3 ×10^-7 meters to 6×10^-10 meters. These waves are produced for reasons similar to light waves and are often emitted during electrical discharges. Because its energy is comparable to the energy involved in general chemical reactions, the chemical effect of ultraviolet light is strong;

(6) Roentgen rays (X-rays)—— This part of the electromagnetic spectrum has wavelengths from 2×10^-9 meters to 6×10^-12 meters. Roentgen rays (X-rays) are emitted when the inner shell electrons of electric atoms jump from one energy state to another or when the electrons slow down in the nuclear electric field;

(7) Gamma rays——are electromagnetic waves with wavelengths from 10^-10 to 10^-14 meters. This invisible electromagnetic wave is emitted from within the nucleus, and is often accompanied by such radiation in radioactive substances or nuclear reactions. Gamma rays have strong penetrating power and are very destructive to living things. From this point of view, the laser energy is not very large, but its energy density is very high (because its range of action is very small, generally only one point), and a large amount of energy can be gathered in a short time, so it can be used as a weapon. Understood.

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