Materials in Electronics/The Electron

This page introduces the basic properties of the electron, the most important particle in electronic physics. This page introduces only what is necessary for the rest of this book to build on. for more detailed information, see the suggested further reading at the end of the page.

The Electron
The electron is a subatomic particle with a negative charge, equal to –1.60217646×10-19 C. Current, or the rate of flow of charge, is defined such that one coulomb, so 1/–1.60217646×10-19, or 6.24150974×1018 electrons flowing past a point per second give a current of one ampere. The charge on an electron is often given as -e. note that charge is always considered positive, so the charge of an electron is always negative.

The electron has a mass of 9.10938188×10-31 kg, or about 1/1840 that of a proton. The mass of an electron is often written as me.

When working, these values can usually be safely approximated to:


 * -e = -1.60×10-19 C
 * me = 9.11×10-31kg