An absorption spectrum is plotted with absorbance in the y-axis and wavelength or frequency in the x-axis. Absorption spectra are used in various analysis techniques such as atomic absorption spectroscopy and UV-absorption spectroscopy.
These techniques are used in identifying a certain species in a given mixture or confirming the identity of a particular species.
When a beam of electromagnetic radiation is sent through a sample of atoms or molecules, the electrons in them absorb energy and transfer themselves to a higher energy state.
Then they fall back to the earlier energy states they occupied by giving away additional energy they absorbed. When the released energy is plotted against the wavelength it is called an emission spectrum. An absorption spectrum is denoted by the dark lines in a bright background whereas the opposite is shown in an emission spectrum. These two are the reverse of each other. For a given element, the absorption lines correspond to the frequencies of the emission lines. This is because the energy absorbed by electrons of a certain element to reach higher energy levels are emitted when they return to the previously occupied energy level.
A continuous spectrum is created by putting both absorption and emission spectra together. The main requirement for a spectrum to be a continuous spectrum is that it should contain all the wavelengths within a given range. Visible light, when diffracted, produce a continuous spectrum. The rainbow contains seven colours which fade into each other without leaving any gap. When a black object is heated to glow it emits radiation in a continuous spectrum. However, scientists say that continuous spectrum also contains gaps and can be seen only when analysed by a spectrometer.
An ideal continuous spectrum should not contain and gap whatsoever. This could only be achieved at perfect lab settings and is very rare. Figure 1: Formation of Continuous Spectrum. Line spectra are generated only in either absorption spectrum or emission spectrum. Hence both are same words with no difference. Hope it helps. Arun askIITians forum expert. Aswanth 18 Points.
Line spectrum and emission spectra are the types. Other Related Questions on Physical Chemistry. View all Questions ». You will get reply from our expert in sometime. We will notify you when Our expert answers your question.
To View your Question Click Here. View courses by askIITians. Click Here Know More. Full Name. Difference between Line Spectrum and Band Spectrum. Comparison between Line Spectrum and Band Spectrum: Line Spectrum Band Spectrum Short description A spectrum of radiation in which the quantity is studied, such as frequency or energy, takes on discrete values.
Also known as Atomic spectra. Molecular spectra. View Appears as parallel lines when viewed from a slit. Appears as continuous form of bands when viewed from a spectroscope. Nature They are distinct and unique. They are continuous and closely spaced with one another. Image Courtesy: scienceinschool. Add new comment Your name.
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