Spectroscopic procedure of analysis is by estimating the intensity and wavelength of radiation that is transmitted or absorbed in the spectrophotometry. This step give foundation for sensitivity procedure for determination and quantization. On the basis of determination and quantization of atoms and molecules, absorption spectroscopy is the instrument used often. While the emission spectroscopy is also used in the determination of atoms or molecule, but have wide area of coverage that involved radiation. The major different of emission spectroscopy, is that the manner in which the induction take place is different from that of absorption spectroscopy. Often the spectroscopic analysis depend on the use of instrument that might sometime be easy and less expensive or  high technical instrument that is highly design with the latest advanced technological development.

Definition of spectroscopy

On the above discussion we said that spectroscopic procedure involved the use of radiation, and radiation often generated from electromagnetic which is called electromagnetic radiation. As such we can define spectroscopy as the procedure that is adopted for investigating the frequency during the interaction of electromagnetic radiation with matter.

Interaction of radiation and matter

Radiation are fixture of energy which either can be absorbed or transmitted, so before interaction can take place in the spectroscopy, there must be a transmissions of different energy level of atoms or molecules that is subjected for analysis. There are different type of interaction such as; reflection, refraction and diffraction. But these type of interaction are often applicable to a large quantity of material, instead of energy level of precise atoms or molecules. Matter emission or absorption is generally involve energy exchange, as such to comprehend the mechanism behind the exchange, it is significant that one must have idea of distribution of energy level within atom or molecules. The following energy are the associated energy that resulted in the generation of the internal energy of a molecule or atoms which are;

1. Electron
2. Vibration between atoms
3. The rotation of various groups of atoms within a molecules.

Alteration of the energy level can take place by absorption or emission of radiation energy, these take place because of existence of atoms within a specific assign number of energy levels. Investigating the Wavelength or frequency of radiation, absorbed or emitted by molecule or atom will provide details information concerning it identity. The procedure of carrying these study is called qualitative spectroscopy.