Ürst of a class of similar complexes
called *sandwich compounds. Its systematic name is di-π-cyclopentadienyl iron(II).
ferrocyanide A compound containing the complex ion [Fe(CN) 6 ]
4–
,
i.e. the hexacyanoferrate(II) ion.
ferroelectric materials Ceramic
dielectrics, such as Rochelle salt and
barium titanate, that have a domain
structure making them analogous to
ferromagnetic materials. They exhibit hysteresis and usually the
piezoelectric effect.
ferromagnetism See magnetism.
ferrosoferric oxide See triiron
tetroxide.
ferrous compounds Compounds
of iron in its +2 oxidation state; e.g.
ferrous chloride is iron(II) chloride,
FeCl 2 .
fertilizer Any substance that is
added to soil in order to increase its
productivity. Fertilizers can be of natural origin, such as composts, or they
can be made up of synthetic chemicals, particularly nitrates and phosphates. Synthetic fertilizers can
increase crop yields dramatically, but
when leached from the soil by rain,
which runs into lakes, they also increase the process of eutrophication.
Bacteria that can Üx nitrogen are
sometimes added to the soil to increase its fertility; for example, in
tropical countries the cyanobacterium Anabaena is added to rice paddies to increase soil fertility.
Übrous protein See protein.
Fick’s law A law describing the diffusion that occurs when solutions of
different concentrations come into
contact, with molecules moving from
regions of higher concentration to regions of lower concentration. Fick’s
law states that the rate of diffusion
dn/dt, called the diffusive flux and denoted J, across an area A is given by:
dn/dt = J = –DA∂c/∂x, where D is a constant called the diffusion constant,
∂c/∂x is the concentration gradient of
the solute, and dn/dt is the amount of
solute crossing the area A per unit
time. D is constant for a speciÜc
solute and solvent at a speciÜc temperature. Fick’s law was formulated
by the German physiologist Adolf
Eugen Fick (1829–1901) in 1855.
Üeld effect See electronic
effects.
Üeld-emission microscope (FEM)
A type of electron microscope in
ferrocyanide
224
f
metal
tip
liquid
helium
electrons electrons electrons
to vacuum
pump
fluorescent
screen
high
negative
voltage
Field-emission microscope
www.AzShimi.ir www.AzShimi.com
called *sandwich compounds. Its systematic name is di-π-cyclopentadienyl iron(II).
ferrocyanide A compound containing the complex ion [Fe(CN) 6 ]
4–
,
i.e. the hexacyanoferrate(II) ion.
ferroelectric materials Ceramic
dielectrics, such as Rochelle salt and
barium titanate, that have a domain
structure making them analogous to
ferromagnetic materials. They exhibit hysteresis and usually the
piezoelectric effect.
ferromagnetism See magnetism.
ferrosoferric oxide See triiron
tetroxide.
ferrous compounds Compounds
of iron in its +2 oxidation state; e.g.
ferrous chloride is iron(II) chloride,
FeCl 2 .
fertilizer Any substance that is
added to soil in order to increase its
productivity. Fertilizers can be of natural origin, such as composts, or they
can be made up of synthetic chemicals, particularly nitrates and phosphates. Synthetic fertilizers can
increase crop yields dramatically, but
when leached from the soil by rain,
which runs into lakes, they also increase the process of eutrophication.
Bacteria that can Üx nitrogen are
sometimes added to the soil to increase its fertility; for example, in
tropical countries the cyanobacterium Anabaena is added to rice paddies to increase soil fertility.
Übrous protein See protein.
Fick’s law A law describing the diffusion that occurs when solutions of
different concentrations come into
contact, with molecules moving from
regions of higher concentration to regions of lower concentration. Fick’s
law states that the rate of diffusion
dn/dt, called the diffusive flux and denoted J, across an area A is given by:
dn/dt = J = –DA∂c/∂x, where D is a constant called the diffusion constant,
∂c/∂x is the concentration gradient of
the solute, and dn/dt is the amount of
solute crossing the area A per unit
time. D is constant for a speciÜc
solute and solvent at a speciÜc temperature. Fick’s law was formulated
by the German physiologist Adolf
Eugen Fick (1829–1901) in 1855.
Üeld effect See electronic
effects.
Üeld-emission microscope (FEM)
A type of electron microscope in
ferrocyanide
224
f
metal
tip
liquid
helium
electrons electrons electrons
to vacuum
pump
fluorescent
screen
high
negative
voltage
Field-emission microscope
www.AzShimi.ir www.AzShimi.com