Table "Electromagnetic Wave Spectrum"
| Wave Range | Frequency | Wavelength | Source | Properties | Applications |
| Radio Waves | 3·10-5 - 3·1012 Hz | 10-3 - 10-4 m | Oscillatory circuit | Travel long distances, reflect from the ionosphere, are modulated | Radio, television, mobile, satellite communication |
| Infrared Waves | 6·1011 - 3.75·1014 Hz | 5·10-4 - 8·10-7 m | Any body heated above 0 K | Exert thermal effect | Food storage, heating, medicine |
| Visible Radiation | 3.75·1014 - 7.5·1014 Hz | 8·10-7 - 4·10-7 m | Bodies heated above 1000 °C | Affects the retina | Photography, videography, lighting |
| Ultraviolet Radiation | 7.5·1014 - 3·1017 Hz | 4·10-7 - 10-9 m | Sun, quartz lamp | Penetrates soft tissues | Disinfection, medicine, tanning |
| X-rays | 1.5·1017 - 5·1019 Hz | 2·10-9 - 6·10-12 m | X-ray tube | High penetrating ability | Medicine, X-ray structural analysis |
| Gamma Radiation | > 5·1019 Hz | > 6·10-12 m | Radioactive isotopes | Very high penetrating ability | Atomic bomb, medicine, studying internal structure of matter |
Electromagnetic waves of various frequencies permeate the space around us. They are divided into ranges with conditional boundaries and overlapping frequencies. The electromagnetic wave spectrum illustrates the distribution of waves by ranges.
Depending on frequency, electromagnetic waves differ in propagation speed, penetrating ability, color, visibility, and biological effects.
Radio waves are used for communication, radar, broadcasting, and space communication.
Infrared (thermal) radiation is significant for life of humans, animals, and plants, which operate within certain temperature ranges.
Visible radiation is the light that enables living organisms to navigate and see surroundings, participates in photosynthesis of plants producing oxygen essential for respiration.
Ultraviolet radiation is electromagnetic radiation with wavelength from 10 to 400 nm and frequency from 7.5·1014 to 3·1016 Hz. The main source is the Sun. The ozone layer protects the Earth from UV. High doses cause skin burns, eye damage, cancer, mutations, and aging.
Artificial sources:
Mercury-containing UV lamps;
Mercury-quartz lamps;
Daylight fluorescent lamps;
Excilamps;
LEDs;
Gas discharges during electric welding;
Argon, nitrogen, excimer lasers.
UV lamps are used for disinfecting tools, surfaces, water, and air; treating purulent inflammations; irradiating dental fillings; drying paints and varnishes; detecting lacquer aging in restoration; verifying currency and documents.
X-rays are electromagnetic radiation with wavelengths from 102 to 10-3 nm and frequencies from 3·106 to 6·1016 Hz.
X-ray tubes generate X-rays.
Applications in medicine, industry, and science:
Radiography;
Dosimetry;
Defect detection;
X-ray structural analysis (chemistry, biology);
Electron microscopy;
X-ray television scanners at airports;
Cryptography.
High doses and frequent exposure lead to serious illnesses.
Gamma radiation is produced in nuclear reactions, has high penetrating ability, and is harmful to humans. Gamma radiation from space (nuclear reactions inside the Sun and stars) is absorbed by the Earth's atmosphere, allowing life to exist.
Additional information:
Frequency range LF, MF, HF, VHF, UHF, SHF, EHF. Limits and conventional designations of bands,
ISM frequencies,
FRS frequencies,
LPD frequencies,
PMR frequencies,
Frequencies of analog TV channels in Moscow,
Frequencies of digital TV channels in Moscow,
Frequencies of TV channels with subcarriers,
Frequencies of FM radio stations in Moscow,
Marine channel frequencies