Spectrum
Definition and meaning of Spectrum in chemistry.
Spectrum is a visual or graphical representation of the distribution of energy, mass, or another physical property as a function of wavelength, frequency, or mass-to-charge ratio.
In more detail
Spectroscopic techniques generate spectra by interacting electromagnetic radiation with matter. As molecules absorb or emit specific energy quanta, the resulting spectrum provides a unique chemical fingerprint. Scientists analyze these intricate patterns to identify molecular structures, determine the exact concentrations of unknown solutes, and deeply study energy level transitions within atoms or complex macromolecules. While the continuous spectrum of visible light spans smoothly from red to violet, a chemical spectrum often features distinct, sharp peaks or broad absorption bands.
Key facts
| Field | Analytical Chemistry |
|---|---|
| Primary Use | Identifying chemical compounds |
| Common Types | Mass, infrared, UV-visible |
| Measured Variables | Wavelength, frequency, energy |
An infrared spectrum of ethanol shows a broad characteristic absorption peak around 3300 cm-1 due to the O-H bond stretching, confirming the presence of an alcohol functional group.
Frequently asked questions
What does a peak in a chemical spectrum indicate?
A distinct peak indicates a specific energy absorption or emission corresponding exactly to a unique molecular or atomic transition.