Band of Colours – The Spectrum
We have heard of many types of spectrums while studying the properties of electromagnetic radiations. The spectrum is an essential concept of Physics that aids to learn the structure and behavior of atoms. When the white light is passed through a prism, it splits into a spectrum of light. The electromagnetic spectrum accommodates wide wavelengths of light from visible light to infrared light.
The most common spectrum of light seen around is the rainbow. The spectrum of light is arranged in the VIBGYOR pattern. Violet, Indigo, Blue, Green, Yellow, Orange, and Red are abbreviated as VIBGYOR. The branch of science that studies the spectrum is known as spectroscopy. A spectroscope or spectrograph is an instrument mainly used to separate the radiations of different wavelengths. In this article let us study in detail the absorption spectrum and emission spectrum. Before that, let us know what is meant by an atomic spectrum.
Atomic Spectra
Atomic spectra are formed when absorption or emission of electromagnetic radiation takes place between different energy levels. We know that light has dual nature, where it can be seen as a particle as well as a wave. Atomic spectra are formed when visible light interacts with atoms or molecules. These atoms or molecules absorb energy and emit radiation of various wavelengths. There are three types of atomic spectra, they are:
- Emission spectra
- Absorption spectra
- Continuous spectra
Atomic spectroscopy is the study of the electromagnetic radiation absorbed or emitted by the atoms. It is used for identifying the spectral lines of materials used in metallurgy. Pharmaceutical industries use atomic spectroscopy to identify the traces of materials. Atomic spectroscopy is also used to examine multidimensional elements.
Absorption and Emission Spectrum
Let us understand what is absorption spectrum and emission spectrum as well as the differences between them.
Electrons of an atom absorb energy and move from lower energy levels to higher energy levels. Excited atoms emit radiation, leading to the formation of an emission spectrum. It comprises colored lines which help in figuring out the composition of a certain matter. An atom will be having higher energy while exhibiting an emission spectrum. The emission spectrum is a discontinuous spectrum with distinct spacing between various wavelengths. The metal filament in a lightbulb produces emission spectra.
The emission spectrum is classified into two types:
- Continuous spectrum
- Line Spectrum
An absorption spectrum includes frequencies of light transmitted with dark bands. This spectrum is formed when the electrons in the ground state absorb energy to reach higher energy states. These kinds of the spectrum are produced when atoms absorb energy. The absorption spectrum is used to find the ability of some objects to retain heat and its absorption level. The wavelengths of light that are absorbed is used to find the number of substances present in the given sample. The Sun produces an absorption spectrum, with dark lines across its spectrum. These are some of the information on the atomic spectra, absorption spectrum as well as emission spectrum.