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::Electromagnetic spectrum

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Class   Freq-
uency
Wave-
length
Energy
Ionizing
radiation
γ Gamma rays   300 EHz 1 pm 1.24 MeV
 
  30 EHz 10 pm 124 keV
HX Hard X-rays  
  3 EHz 100 pm 12.4 keV
SX Soft X-rays  
  300 PHz 1 nm 1.24 keV
 
  30 PHz 10 nm 124 eV
EUV Extreme
ultraviolet
 
  3 PHz 100 nm 12.4 eV
  NUV Near
ultraviolet
 
Visible   300 THz 1 μm 1.24 eV
NIR Near infrared  
    30 THz 10 μm 124 meV
MIR Mid infrared  
  3 THz 100 μm 12.4 meV
FIR Far infrared  
  300 GHz 1 mm 1.24 meV
Micro-
waves


and

radio
waves
EHF Extremely high
frequency
 
  30 GHz 1 cm 124 μeV
SHF Super high
frequency
 
  3 GHz 1 dm 12.4 μeV
UHF Ultra high
frequency
 
  300 MHz 1 m 1.24 μeV
VHF Very high
frequency
 
  30 MHz 10 m 124 neV
HF High
frequency
 
  3 MHz 100 m 12.4 neV
MF Medium
frequency
 
  300 kHz 1 km 1.24 neV
LF Low
frequency
 
  30 kHz 10 km 124 peV
VLF Very low
frequency
 
  3 kHz 100 km 12.4 peV
  VF /
ULF
Voice frequency /
Ultra low frequency
 
  300 Hz 1 Mm 1.24 peV
SLF Super low
frequency
 
  30 Hz 10 Mm 124 feV
ELF Extremely low
frequency
 
  3 Hz 100 Mm 12.4 feV
 
Sources: File:Light spectrum.svg <ref>What is Light?UC Davis lecture slides Archived July 23, 2014 at the Wayback Machine</ref><ref>{{#invoke:citation/CS1|citation CitationClass=web

}}</ref><ref>{{#invoke:citation/CS1|citation

CitationClass=web

}}</ref>

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The "electromagnetic spectrum" of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.

The electromagnetic spectrum extends from below the low frequencies used for modern radio communication to gamma radiation at the short-wavelength (high-frequency) end, thereby covering wavelengths from thousands of kilometers down to a fraction of the size of an atom. The limit for long wavelengths is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length.<ref>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> Until the middle of last century it was believed by most physicists that this spectrum was infinite and continuous.

Most parts of the electromagnetic spectrum are used in science for spectroscopic and other probing interactions, as ways to study and characterize matter.<ref name="em-spectrum">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In addition, radiation from various parts of the spectrum has found many other uses for communications and manufacturing (see electromagnetic radiation for more applications).


Electromagnetic spectrum sections
Intro  [[Electromagnetic_spectrum?section=History_of_electromagnetic_spectrum_discovery{{safesubst:#invoke:anchor|main}}|History of electromagnetic spectrum discovery{{safesubst:#invoke:anchor|main}}]]  Range of the spectrum  Rationale for spectrum regional names  Types of radiation  See also  Notes and references  External links  

PREVIOUS: IntroNEXT: [[Electromagnetic_spectrum?section=History_of_electromagnetic_spectrum_discovery{{safesubst:#invoke:anchor|main}}|History of electromagnetic spectrum discovery{{safesubst:#invoke:anchor|main}}]]
<<[[Electromagnetic_spectrum?section=History_of_electromagnetic_spectrum_discovery{{safesubst:#invoke:anchor|main}}|>>]]

---col::style    Rowspan::right    Spectrum::empty    Padding::light    First::waves    X-rays::energy

Class   Freq-
uency
Wave-
length
Energy
Ionizing
radiation
γ Gamma rays   300 EHz 1 pm 1.24 MeV
 
  30 EHz 10 pm 124 keV
HX Hard X-rays  
  3 EHz 100 pm 12.4 keV
SX Soft X-rays  
  300 PHz 1 nm 1.24 keV
 
  30 PHz 10 nm 124 eV
EUV Extreme
ultraviolet
 
  3 PHz 100 nm 12.4 eV
  NUV Near
ultraviolet
 
Visible   300 THz 1 μm 1.24 eV
NIR Near infrared  
    30 THz 10 μm 124 meV
MIR Mid infrared  
  3 THz 100 μm 12.4 meV
FIR Far infrared  
  300 GHz 1 mm 1.24 meV
Micro-
waves


and

radio
waves
EHF Extremely high
frequency
 
  30 GHz 1 cm 124 μeV
SHF Super high
frequency
 
  3 GHz 1 dm 12.4 μeV
UHF Ultra high
frequency
 
  300 MHz 1 m 1.24 μeV
VHF Very high
frequency
 
  30 MHz 10 m 124 neV
HF High
frequency
 
  3 MHz 100 m 12.4 neV
MF Medium
frequency
 
  300 kHz 1 km 1.24 neV
LF Low
frequency
 
  30 kHz 10 km 124 peV
VLF Very low
frequency
 
  3 kHz 100 km 12.4 peV
  VF /
ULF
Voice frequency /
Ultra low frequency
 
  300 Hz 1 Mm 1.24 peV
SLF Super low
frequency
 
  30 Hz 10 Mm 124 feV
ELF Extremely low
frequency
 
  3 Hz 100 Mm 12.4 feV
 
Sources: File:Light spectrum.svg <ref>What is Light?UC Davis lecture slides Archived July 23, 2014 at the Wayback Machine</ref><ref>{{#invoke:citation/CS1|citation CitationClass=web

}}</ref><ref>{{#invoke:citation/CS1|citation

CitationClass=web

}}</ref>

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The "electromagnetic spectrum" of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.

The electromagnetic spectrum extends from below the low frequencies used for modern radio communication to gamma radiation at the short-wavelength (high-frequency) end, thereby covering wavelengths from thousands of kilometers down to a fraction of the size of an atom. The limit for long wavelengths is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length.<ref>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> Until the middle of last century it was believed by most physicists that this spectrum was infinite and continuous.

Most parts of the electromagnetic spectrum are used in science for spectroscopic and other probing interactions, as ways to study and characterize matter.<ref name="em-spectrum">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In addition, radiation from various parts of the spectrum has found many other uses for communications and manufacturing (see electromagnetic radiation for more applications).


Electromagnetic spectrum sections
Intro  [[Electromagnetic_spectrum?section=History_of_electromagnetic_spectrum_discovery{{safesubst:#invoke:anchor|main}}|History of electromagnetic spectrum discovery{{safesubst:#invoke:anchor|main}}]]  Range of the spectrum  Rationale for spectrum regional names  Types of radiation  See also  Notes and references  External links  

PREVIOUS: IntroNEXT: [[Electromagnetic_spectrum?section=History_of_electromagnetic_spectrum_discovery{{safesubst:#invoke:anchor|main}}|History of electromagnetic spectrum discovery{{safesubst:#invoke:anchor|main}}]]
<<[[Electromagnetic_spectrum?section=History_of_electromagnetic_spectrum_discovery{{safesubst:#invoke:anchor|main}}|>>]]