faraday far·a·day (fār'ə-dā')
The electric charge required to deposit or liberate 1 gram equivalent weight of a substance in electrolysis, approximately 9.6494 × 104 coulombs.
A measure of electric charge equal to the charge carried by one mole of electrons, about 96,494 coulombs per mole. The faraday is used in measurements of the electricity required to break down a compound by electrolysis.
British physicist and chemist whose experiments into the connections between electricity, magnetism, and light laid the foundation for modern physics. In addition to discovering electromagnetic induction, he invented the electric motor, generator, and transformer, and he discovered the carbon compound benzene.
Our Living Language : The nineteenth century saw rapid growth in the understanding of electricity and magnetism, and much of this progress was due to Michael Faraday. There was no hint from his humble beginnings that he was to become a great scientist. Born in 1791, the son of an English blacksmith, Faraday received little formal schooling. At 14 he was apprenticed to a bookbinder, and it was during this time that he developed an interest in science. In 1812 he attended a series of lectures by Humphry Davy, the well-known chemist. Later in the year, Faraday sent Davy his notes on the talks, asking to become his assistant. When an opening became available, Davy took him on. Faraday, a truly gifted experimenter, started amassing an impressive body of work, converting electrical into mechanical energy (1821), liquefying chlorine (1823), and isolating benzene (1825). He made perhaps his greatest discovery—electromagnetic induction—in 1831, when he produced electricity from magnetism by moving a magnet inside a wire coil. Faraday also came up with the concept of electric and magnetic fields. When James Clerk Maxwell put Faraday's ideas into mathematical form (Faraday knew little mathematics), they became a cornerstone of physics. It was Faraday's research that helped transform electricity from a scientific curiosity into a workable technology. But he also transformed the language, helping to coin the words anode, cathode, ion, and electrode, among others. It is only fitting that there are now two words named after him: farad, the unit of capacitance, and faraday, a unit used to measure the amount of electrical charge.