Contents
The study of Physics Topics involves the exploration of matter, energy, and the forces that govern the universe.
How can the Temperature of a Substance be Determined with the Help of Spectral Analysis?
Different Parts of Electromagnetic Spectrum
It has been found on analysing solar spectrum and the spectra of different objects that there are wavelengths of light which are greater or less than the wavelengths of visible light. The proper-ties of these radiations are similar to those of visible light. These are called electromagnetic waves.
They move with the velocity of light. They also exhibit properties like reflection, refraction, interference, diffraction, polarisation etc. Different parts of an electromagnetic spectrum are discussed elaborately in the chap-ter ‘Electromagnetic wave’.
Application of Spectral Analysis
We can get lots of information about an element by spectral analysis. Spectral analysis is used in the following areas:
1. Identification of an element: we can detect an element by its own characteristic spectrum even if it is present in very small quantities. Each elementary substance either in gaseous or in vapour state under suitable stimulus produces its own peculiar spectrum. As for example, lithium gives a red line, sodium gives only two yellow lines.
2. Determination of temperature of a substance: The nature of the continuous spectrum of a substance depends on its temperature. So by the analysis of continuous spectrum we can get approximately the temperature of a substance. By studying the spectrum of light of a distant star we can get an idea of its temperature. In this context, Saha equation on thermal ionisation of elements deduced by Dr. Megnad Saha is immensely useful.
3. Determination of chemical composition of a substance: The atoms of gaseous elements give rise to line spectra. This line spectrum indicates the nature of an element, i.e., it can be said that line spectra are different for atoms of different elements. So by studying the spectrum obtained from a substance we can know what elements are present in it. So, atomic and molecular structure of matter, temperature of matter, elements present in sun and other stars and planets and their quantities, presence of any unknown element can be found with the help of spectral analysis.?