Infrared radiation (IR)

Definition

Infrared radiation (IR) is electromagnetic radiation with wavelengths longer than visible light but shorter than microwave radiation. It is commonly associated with heat and has a range of wavelengths from about 700 nm to 1 mm.

5 Must Know Facts For Your Next Test

1. Infrared radiation is part of the electromagnetic spectrum, lying between visible light and microwaves in terms of wavelength.
2. The energy of infrared photons is lower than that of visible light photons but higher than that of microwave photons.
3. $E = h\nu$ where $E$ is the energy, $h$ is Planck's constant, and $\nu$ is the frequency; this relationship applies to infrared photons as well.
4. Infrared spectroscopy is used in physics to study molecular vibrations and rotational transitions, providing information about molecular structure.
5. Objects emit infrared radiation as a function of their temperature; this principle underlies thermal imaging technology.

Related terms

Photon: A quantum of electromagnetic radiation that carries energy proportional to its frequency.

Electromagnetic Spectrum: The range of all types of electromagnetic radiation, from radio waves to gamma rays.

$E = h\nu$: $E = h\nu$ represents the energy ($E$) of a photon, where $h$ is Planck's constant and $\nu$ is the frequency.