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Various types of spectra

Various types of spectra:
When white light from the sun or candle or electric bulb is passed through a prism,it splits into a set of series of colour bands known as rainbow of colours:violet,indigo,blue,green,yellow,orange and red (vibgyor).This phenomenon is known as dispersion and the pattern of colours obtained is known as continuous spectrum.Depending upon the source of radiation, the spectra are broadly classified into two types:
(1).emission spectra
(2).absorption spectra
1).Emission spectra:
Emission spectra are obtained by the emission of radiant energy from a source of light like the sun or by a substance in the excited state.
The emission spectra are mainly of two types:
(a) continuous spectra
(b) line spectra or discontinuous spectra or atomic spectra.
(a) Continuous spectrum:
When white light from any source such as sun or electric bulb is passed through a prism,a continuous band of seven colours from red to violet as observed in a rainbow are obtained.such a spectrum is known as continuous spectrum.
(b) Line spectrum or atomic spectrum or discontinuous spectrum:
A spectrum which is not continuous but consists of a few sharp lines each having a definite wavelength is known as line spectrum or atomic spectrum.It has been observed that each element shows a characteristic spectrum which is different from that of other elements.As finger prints of two persons do not match,similarly atomic spectra of two elements do not match.Due to this reason,atomic spectra are also called the finger prints of the elements.
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