Scientific Glossary
- Electromagnetic spectrum: Range of all possible electromagnetic radiation, from radio waves to gamma rays.
- Electromagnetic wave: A self-propagating wave in space with electric and magnetic components that oscillate at right angles to each other and the direction of propagation.
- Electron-hole pair: Created in a semiconductor when light excites an electron out of its energy level in the valence band into the conduction band, leaving a hole in the valence band.
- Electrospray: Ionization technique used in mass spectrometry.
- Error budget: Bit-error requirement allocated to different communication system segments, such as switching or access.
- Ethyl radical: Hydrocarbon radical C2H5 derived by removing a hydrogen atom from ethane; it is a model for the decomposition products of atmospheric chlorofluorocarbons.
- Exciton: Large and strongly interactive particles formed when an electron, excited by a photon into the conduction band of a semiconductor, binds with the positively charged hole it left behind in the valence band.
- Extended state: State in which electron wave functions are spread over many sites, not just a single atom.