where oxidation and reduction occurs. The anode is
where OXIDATIONtakes place; the cathode is where
REDUCTIONtakes place.
electrode potential Electrode potential of an elec-
trode is defined as the electromotive force (emf) of a
cell in which the electrode on the left is a standard
hydrogen electrode, and the electrode on the right is
the electrode in question.
See alsoREDOX POTENTIAL.
electrofuge A LEAVING GROUP that does not carry
away the bonding electron pair. For example, in the
nitration of benzene by NO 2 +, H+is the electrofuge.
The adjective form of electrofugeis electrofugal.
See alsoELECTROPHILE; NUCLEOFUGE.
electrogenic pump Any large, integral membrane
protein (pump) that mediates the movement of a sub-
stance (ions or molecules) across the plasma membrane
against its energy gradient (active transport). The pump
can be ATP-dependent or Na+-dependent; moves net
electrical charges across the membrane.
electrolysis The process whereby an electric current
passes through a substance to cause a chemical change;
produces an oxidation–reduction reaction.
electrolyte A substance whose liquid form conducts
electricity. It may be a solution or a pure ionic liquid.
electromagnetic radiation Energy propagated as
time-varying electric and magnetic fields. These two
fields are inextricably linked as a single entity, since
time-varying electric fields produce time-varying mag-
netic fields and vice versa. Light and radar are exam-
ples of electromagnetic radiation, differing only in their
wavelengths (or frequency). Electric and magnetic fields
propagate through space at the speed of light.
electromagnetic spectrum The entire spectrum of
radiation arranged according to frequency and wave-
length that includes visible light, radio waves,
microwaves, infrared, ultraviolet light, X rays, and
gamma rays. Ranges in wavelength from less than a
nanometer, i.e., X and gamma rays (1 nm is about the
length of 10 atoms in a row) to more than a kilometer,
i.e., radio waves. Wavelength is directly related to the
amount of energy the waves carry. The shorter the radi-
ation’s wavelength, the higher is its energy, ranging
from high frequency (gamma rays) to low frequency
(AM radio). All electromagnetic radiation travels
through space at the speed of light, or 186,000 miles
(300,000 km) per second.Electromagnetic Spectrum
(note: the figures are only approximate)Wavelength Frequency
Radiation (m) (Hz)
gamma radiation –10–12 1019 –
X rays 10 –12–10–9 1017 –10^20
ultraviolet radiation 10 –9–10–7 1015 –10^18
visible radiation 10 –7–10–6 1014 –10^15
infrared radiation 10 –6–10–4 1012 –10–14
microwaves 10 –4 –1 109 –10^13
radio waves 1– –10^990 electrode potential
Electrolysis. The process whereby an electric current passes
through a substance to cause a chemical change; produces an
oxidation–reduction reaction.