Atomic Spectra
Atomic spectra are unique patterns of light emitted or absorbed by atoms. These spectra act like fingerprints of elements and help scientists identify substances in stars, laboratories, and distant galaxies. Atomic spectroscopy is the study of the electromagnetic radiation absorbed and emitted by atoms.
Since unique elements have characteristic (signature) spectra, atomic spectroscopy, specifically the electromagnetic spectrum or mass spectrum, is applied for determination of elemental compositions.
It can be divided by atomization source or by the type of spectroscopy used. In the latter case, the main division is between optical and mass spectrometry.
Mass spectrometry generally gives significantly better analytical performance, but is also significantly more complex. This complexity translates into higher purchase costs, higher operational costs, more operator training, and a greater number of components that can potentially fail. Because optical spectroscopy is often less expensive and has performance adequate for many tasks, it is far more common Atomic absorption spectrometers are one of the most commonly sold and used analytical devices.
Spectroscopy
The energy of electromagnetic radiation is: E = hc/λ- Where,
- h = Plank’s constant
- c = velocity of light
- λ = wave length of light
Causes atomic spectra
The Atomic emission spectra is produced when excited electrons return to the ground state. When electrons return to a lower energy level than they emit energy in the form of light.
The emitted light corresponds to energies of the specific electrons. When atoms are excited they emit light of certain wavelengths which correspond to different colors.
The emitted light can be observed as a series of colored lines with dark spaces in between, this series of colored lines is called a atomic spectra.
The each packet of energy corresponds to a line in the atomic spectrum means there is nothing between each line therefore the spectrum is not continuous.
The uses of Atomic Spectroscopy
Atomic Spectroscopy is used for identifying the spectral lines of materials used in metallurgy.
Atomic Spectroscopy is used in pharmaceutical industries to find the traces of materials used.
Atomic Spectroscopy can be used to study multidimensional elements.
The types of atomic spectroscopy
Atomic emission spectroscopy
Atomic emission spectroscopy involves the transfer of energy from the ground state to an excited state. The electronic transition can be explained in atomic emission.
Atomic absorption spectroscopy
This requires identical energy difference between the lower and higher energy levels. Atomic absorption spectroscopy principle uses the fact that the free electrons generated in an atomizer can absorb radiation at specific frequency.
In the gaseous state, quantifies the absorption of ground-state atoms.
Atomic fluorescence spectroscopy
Atomic fluorescence spectroscopy is a combination of atomic emission and atomic absorption as it involves radiation of both excitation and de-excitation.
Summary
Atomic spectra are special patterns of light produced when atoms absorb or emit energy. Every chemical element creates its own unique spectrum, which acts like a fingerprint for identifying that element.
When energy is supplied to an atom, its electrons become excited and move to higher energy levels. These excited states are unstable. After a very short time, the electrons return to lower energy levels and release excess energy in the form of electromagnetic radiation.
The emitted or absorbed radiation does not contain all possible wavelengths. Instead, only specific wavelengths appear, producing bright or dark lines known as spectral lines. The collection of these spectral lines forms the atomic spectrum of an element.
Why Atomic Spectra are Important?
- Help scientists identify unknown elements
- Used to study stars and distant galaxies
- Provide evidence for quantized energy levels
- Support Bohr’s atomic model
- Used in spectroscopy and chemical analysis