In infrared (IR) spectroscopy, infrared light interacts with molecules of the substance. The collected data 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. As a result, the covalent bonds absorb the beam, thus causing a change in the dipole moment vibrations in the substance. This spectroscopy is mainly used in organic and inorganic chemistry to determine the functional groups in the substance, since different functional groups have specific vibrations when absorbing 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 the 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 collected by IR spectroscopy can be interpreted by a graph of the material's IR spectrum. In such a graph, the wavenumber is on the x-axis, while the transmittance percentage is on the y-axis. The percentage of transmittance indicates the strength of light absorbed by the substance at each frequency. Furthermore, the graph is divided into two areas: the functional 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 different...... center of the paper......nce. The intensity of the light reflected from the sample substance is also compared to the intensity of the light before it passes through the material. The basis of this spectroscopy is based on the concept of electronic transition. Pi electrons (electrons in a pi bond) can become excited because the molecule containing them absorbs ultraviolet and/or visible light. As a result, the electrons move to a higher anti-bonding molecular orbital. This orbital contains an electron which is located in the outer region between two nuclei. In other words, an anti-bonding orbital contains lone pairs of electrons. The difference in 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.