Pattern of properties arranged in order of increasing or decreasing magnitude. In analytical applications, the property measured varies according to the analytical technique being employed. In mass spectroscopy, a mass spectrum with a range of masses is produced. An emission spectrum represents the range of radiations emitted when a substance is heated, bombarded by electrons or ions, or absorbs photons. An absorption spectrum shows the energies absorbed from a continuous spectrum of radiation by an absorbing medium. Spectra produced by an unknown substance can be compared with those of a standard to give information about the composition of the sample.