In infrared (IR) spectroscopy, infrared light interacts with the molecules of the substance. The data collected is used to determine the substance. Infrared light is part of the electromagnetic spectrum and contains longer wavelengths than visible light. In this type of spectroscopy, an IR beam passes through the sample substance. Therefore, the covalent bonds absorb the beam, which causes a change in the vibrations of the dipole moment in the substance. This spectroscopy is mainly used in organic and inorganic chemistry in order to determine the functional groups in the substance, because various functional groups have specific vibrations when they absorb the IR beam. A dipole moment is the degree of separation between two opposite charges. The dipole moment can be stretched or bent within the compound. Additionally, stronger bonds in substance and light atoms will vibrate or rotate at a higher frequency, thus acquiring a higher wavenumber. A wavenumber is the number of wave cycles in one centimeter. The information gathered through IR spectroscopy can be interpreted from a graph of the material's IR spectrum. On such a graph, the wavenumber is on the x-axis, while the transmission percentage is on the y-axis. The transmittance percentage indicates the strength of light absorbed by the substance at each frequency. Additionally, the graph is divided into two areas: the feature group and the fingerprint region. The functional group region on the graph is between 4000 cm-1 and 1000 cm-1, while the region below 1000 cm-1 is considered the fingerprint region. The fingerprint region is composed of a series of difficult absorptions. A mass spectroscopy creates a spectrum based on the masses of the differences...... middle of paper ......nce. The intensity of light reflected from the sample substance is also compared to the intensity of light before it passes through the material. The basis of this spectroscopy is based on the notion of electronic transition. Pi electrons (electrons in a pi bond) can be excited when the molecule containing them absorbs ultraviolet and/or visible light. As a result, electrons move to a higher anti-bonding molecular orbital. This orbital contains an electron located in the outer region between two nuclei. In other words, an anti-bonding orbital contains pairs of free electrons. The difference between the orbitals determines the wavelength and frequency of the light absorbed by the substance. This collected data allows scientists to deduce the identity of the compound. Generally, this spectroscopy is frequently used for quantitative measurements.