boiling point of water was the highest point, changing it
to 212 degrees, as Fahrenheit had earlier indicated in a
publication on the boiling points of various liquids. The
freezing point became 32 degrees (body temperature
became 98.6 degrees, which we use today). This is the
scale that is presently used in today’s thermometers in
the United States and some English-speaking countries,
although most scientists use the Celsius scale.
By 1779 there were some 19 different scales in use
on thermometers, but it was Fahrenheit, as well as
astronomer ANDERSCELSIUSand Jean Christin, whose
scales, when presented in 1742 and 1743, helped
finally set the standards for an accurate thermometer
that are still in use today. Besides making thermome-
ters, Fahrenheit was the first to show that the boiling
point of liquids varies at different atmospheric pres-
sures, and he suggested this as a principle for the con-
struction of barometers. Among his other contributions
were a pumping device for draining the Dutch polders
and a hygrometer for measuring atmospheric humidity.
Fahrenheit died on September 16, 1736, at The
Hague at age 50. There is virtually no one in the
English-speaking countries today who does not have a
thermometer with his initials on it.
fallout The ground fall of dust and other debris
raised to great heights in the atmosphere by a violent
explosion. Also applied to radioactive fallout from an
atomic or thermonuclear explosion.
faraday The charge carried by one mole of electrons
is known as one faraday (symbol F). One faraday of
electricity corresponds to the charge on 6.022 × 1023
electrons, or 96,487 coulombs.
Faraday’s law of electrolysis Relates to the number
of electrons required to discharge one mole of an ele-
ment. One equivalent weight of a substance is pro-
duced at each electrode during the passage of 96,487
coulombs of charge through an electrolytic cell.
See alsoFARADAY.
fast-atom bombardment mass spectroscopy(FAB
mass spectroscopy) A method in which ions are pro-
duced in a mass spectrometer from nonvolatile or ther-
mally fragile organic molecules by bombarding the
compound in the condensed phase with energy-rich
neutral particles.fast neutron In a nuclear reaction, a neutron ejected
at high kinetic energy.fat (general) Any substance made up of LIPIDs or
FATTY ACIDs that supply calories to the body and can
be found in solid or liquid form (e.g., margarine, veg-
etable oil); three fatty acids linked to a glycerol
molecule form fat.fat (triacylglycerol) Triacylglycerols are storage
LIPIDs, consisting of three similar to different FATTY
ACIDs attached to a glycerol molecule. They are found
mostly stored in adipose (fat) cells and tissues and are
highly concentrated regions of metabolic energy. Since
there are abundant reduced CH groups available in
them for oxidation-required energy production, they
are excellent storage containers of energy. Can be
found in plants, animals, and animal plasma lipopro-
teins for lipid transport. Formerly known as triglyc-
erides.fatty acid Fatty acids are the components of two LIPID
types mostly found in cells in the form of large lipids or
small amounts in free form: storage fats and structural
phospholipids. They consist of long hydrocarbon chains
of varying length (from four to 24 carbon atoms), con-
taining a terminal CARBONYL GROUPat one end, and
they may be saturated (having only a single carbon-to-
carbon bond), or unsaturated (one or more double or
triple carbon-to-carbon bonds). The number and loca-
tion of double bonds also vary. More than 70 different
kinds have been found in cells. Saturated fatty acids
cause higher levels of blood CHOLESTEROL, since they
have a regulating effect on its synthesis, but unsaturated
ones do not have that effect and nutritionally are pro-
moted more. Some fatty acids are palmitic acid, palmi-
toleic acid, alpha-linolenic acid, eleostearic acid, linoleic
acid, oleic acid, and elaidic acid. Three fatty acids
linked to a glycerol molecule form FAT.fatty acid 107