Part of the Electronics glossary:

An electron is a negatively charged subatomic particle. It can be either free (not attached to any atom), or bound to the nucleus of an atom. Electrons in atoms exist in spherical shells of various radii, representing energy levels. The larger the spherical shell, the higher the energy contained in the electron.

In electrical conductors, current flow results from the movement of electrons from atom to atom individually, and from negative to positive electric poles in general. In semiconductor materials, current also occurs as a movement of electrons. But in some cases, it is more illustrative to envision the current as a movement of electron deficiencies from atom to atom. An electron-deficient atom in a semiconductor is called a hole. Holes "move" from positive to negative electric poles in general.

The charge on a single electron is considered as the unit electrical charge. It is assigned negative polarity. The charge on an electron is equal, but opposite, to the positive charge on a proton or hole. Electrical charge quantity is not usually measured in terms of the charge on a single electron, because this is an extremely small charge. Instead, the standard unit of electrical charge quantity is the coulomb, symbolized by C, representing about 6.24 x 1018 electrons. The electron charge, symbolized by e, is about 1.60 x 10-19 C. The mass of an electron at rest, symbolized me, is approximately 9.11 x 10-31 kilogram (kg). Electrons moving at an appreciable fraction of the speed of light, for example in a particle accelerator, have greater mass because of relativistic effects.

This was last updated in September 2005
Posted by: Margaret Rouse

Related Terms

Definitions

  • bioprinting

    - Although bioprinting is still in the experimental stage and is currently used primarily in scientific study rather than applied science, the possibility of creating functional replacement tissues o... (WhatIs.com)

  • flash storage

    - Flash storage, based on flash memory, is used for data repositories, storage systems and consumer devices, such as USB drives, smartphones and solid-state drives. Flash-based storage is faster than... (WhatIs.com)

  • digital assistant

    - A digital assistant is an application program that can understand natural human language and complete electronic tasks for the end user. (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.