View source for Emission Spectroscopy

== Introduction ==
Emission spectroscopy is a method used in scientific analysis to identify elements or compounds in a sample of material. It involves the measurement of the [[Electromagnetic radiation|electromagnetic radiation]], including visible light, emitted by the material. Emission spectroscopy has a wide range of applications, from the analysis of chemical samples in a laboratory to the study of distant stars in [[Astrophysics|astrophysics]].

[[Image:Detail-49961.jpg|thumb|center|A laboratory setup showing a sample being subjected to high energy, causing it to emit light which is then analyzed by a spectrometer.|class=only_on_mobile]]
[[Image:Detail-49962.jpg|thumb|center|A laboratory setup showing a sample being subjected to high energy, causing it to emit light which is then analyzed by a spectrometer.|class=only_on_desktop]]

== Principles of Emission Spectroscopy ==
The principles of emission spectroscopy are based on the behavior of atoms and molecules when they absorb and then re-emit energy. When an atom or molecule absorbs energy, it becomes excited and moves to a higher energy state. This excited state is unstable, and the atom or molecule will return to its ground state by emitting energy in the form of light. The wavelength of this emitted light is characteristic of the particular atom or molecule, and by measuring this wavelength, it is possible to identify the element or compound.

== Types of Emission Spectroscopy ==
There are several types of emission spectroscopy, including atomic emission spectroscopy (AES), molecular emission spectroscopy, and X-ray emission spectroscopy. Each of these types uses a different method to excite the atoms or molecules in the sample and has its own set of applications.

=== Atomic Emission Spectroscopy ===
In [[Atomic emission spectroscopy|atomic emission spectroscopy]] (AES), the sample is typically vaporized and then excited by an electric current or a flame. The atoms in the sample emit light at characteristic wavelengths, which are then measured by a spectrometer.

=== Molecular Emission Spectroscopy ===
In molecular emission spectroscopy, the sample is usually a gas or a liquid that is excited by heat, electricity, or a laser. The molecules in the sample emit light at wavelengths that are characteristic of the molecular structure.

=== X-ray Emission Spectroscopy ===
In [[X-ray emission spectroscopy|X-ray emission spectroscopy]], the sample is bombarded with high-energy X-rays, which cause the atoms in the sample to emit X-rays at characteristic wavelengths. This method is particularly useful for identifying elements in solid samples.

== Applications of Emission Spectroscopy ==
Emission spectroscopy has a wide range of applications in various fields of science and industry. It is used in chemistry to identify elements and compounds in samples, in environmental science to monitor air and water quality, in medicine to analyze biological samples, and in astrophysics to study the composition of stars and other celestial bodies.

== See Also ==
* [[Absorption spectroscopy]]
* [[Fluorescence spectroscopy]]
* [[Raman spectroscopy]]

[[Category:Spectroscopy]]
[[Category:Analytical chemistry]]
[[Category:Physical chemistry]]