The space where a charged particle experiences force.

Property of matter, carried by elementary particles (protons are positively charged, electrons are negatively). Electric charge, which can be positive or negative, occurs in discrete natural units and is neither created nor destroyed.

By this term we refer to the numerous phenomena that result from the directed motion of electrons due to the presence of an electric field.

The conversion of electricity directly into light.

The electromagnetic fields are spaces where invisible forces occur anytime electricity is being used.

Emission or transmission of energy through space or through a material medium in the form of electromagnetic waves.

Elementary (subatomic) particle of the atom that travels around the nucleus, being contained within fixed regions of space termed orbitals (energy levels or shells). Electrons are negatively charged.

A collective scattering phenomenon with electrons being (nearly elastically) scattered by atoms in a regular array (crystal).

An electron hole (usually referred to simply as a hole) is the absence of an electron from the otherwise full valence band.

A unit of energy equal to the energy acquired by an electron falling through a potential difference of one volt.

The particular distribution of electrons among available shells or orbitals.

The movement of an electron in an atom or molecule from a lower energy state (an orbital closer to the nuclei) to a higher energy state.

A branch of technology involving components, devices and systems which operate by modification of the optical properties of a material by an electric field.

Any substance that cannot be broken up into simpler  substances by chemical means. Currently 115 elements have been observed and are displayed in the Periodic Table of Elements. Gold, silver, iodine, oxygen and nickel are examples of elements.

Two nonsuperimposable objects which are mirror images of each other are. The term enantiomer is synonymous with enantiomorph. For example, the letters b and d are enantiomers of each other.

The position in which electrons orbit around the nucleus. Each energy level (or shell) can hold a set number of electrons.

A protein that functions as a catalyst meaning that it speeds up the rate of reaction between substances.

 Laboratory methods for studying enzyme activity

The addition of the amount of energy (excitation energy) necessary to a system that results in its alteration, ordinarily from the condition of lowest energy (ground state) to one of higher energy (excited state). Talking in detail, electrons in an atom may absorb the photons' energy and jump to a higher energy level in outer shells. When this happens, the atom is said to be "excited". Very soon, the electrons lose the extra energy and return to a lower level shell -a process called “de-excitation” of the atom. If the photon energy is too high, the electrons may even escape from the material (case of the photoelectric effect).

A discrete amount of energy needed to be absorbed in order an electron of the particlar atom to excite.