Elementary Charge

What Does Elementary Charge Mean?

An elementary charge is the magnitude of electric
charge associated with a single electron. Similar to time, length or mass, the
elementary charge is a fundamental measurement of a fundamental physical
constant. The coulomb is the unit of elementary charge in the International System
of Units.


Techopedia Explains Elementary Charge

The elementary charge is usually represented by e. In order to avoid confusion on the sign, e is normally considered as a positive elementary charge. In other words, protons have a positive e charge, whereas electrons have a negative e charge. The elementary charge is also the electrical charge carried by a proton, however with opposite polarity. The measured value of the elementary charge is approximately (1.602 176 487 ± 0.000 000 040) × 10-19 coulombs or 4.8 × 10−19 statcoulombs in cgs units. The elementary charge was defined before the discovery of quarks, and outside of particle physics, the elementary charge is still considered the smallest electrical charge possible.

The importance of the elementary charge lies in that fact almost all freely existing charged subatomic matter discovered so far, including electrons, have an electric charge equal to the value of the elementary charge or can be expressed by whole number multiples of the value. When it comes to quarks, their charges can be expressed as a fraction such as one-third or two-thirds of the value.


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Margaret Rouse

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.