bonate, and sodium perborate. When
sprayed with the reagent, traces of
blood (even old blood) emit a faint
chemoluminescence.
LUMO See lowest unoccupied molecular orbital.
lutetium Symbol Lu. A silvery
metallic element belonging to the
*lanthanoids; a.n. 71; r.a.m. 174.97;
r.d. 9.8404 (20°C); m.p. 1663°C; b.p.
3402°C. Lutetium is the least abundant of the elements and the little
quantities that are available have
been obtained by processing other
metals. There are two natural isotopes, lutetium–175 (stable) and
lutetium–176 (half-life 2.2 × 10
10
years). The element is used as a catalyst. It was Ürst identiÜed by Gerges
Urbain (1872–1938) in 1907.
A
• Information from the WebElements site
lux Symbol lx. The SI unit of illuminance equal to the illumination produced by a luminous Ûux of 1 lumen
distributed uniformly over an area of
1 square metre.
lyate ion The ion formed by removing a hydron from a molecule of
a solvent. In water, for example, the
hydroxide ion (OH
– ) is the lyate ion.
lye See potassium hydroxide.
Lyman series See hydrogen spectrum.
lyonium ion The ion formed by
adding a hydron (H
+ ) to a solvent
molecule. For example, in ethanol,
C 2 H 5 OH 2
+ is the lyonium ion.
lyophilic Having an afÜnity for a
solvent (‘solvent-loving’; if the solvent is water the term hydrophilic is
used). See colloids.
lyophobic Lacking any afÜnity for
a solvent (‘solvent-hating’; if the solvent is water the term hydrophobic is
used). See colloids.
lyotropic mesomorph An
arrangement taken by micelles
formed from surfactant molecules in
concentrated solutions. A lyotropic
mesomorph consists of long cylinders in a fairly close-packed hexagonal arrangement. Lyotropic
mesomorphs are sometimes called
liquid crystalline phases for micelles.
lysergic acid diethylamide (LSD)
A chemical derivative of lysergic acid
that has potent hallucinogenic properties (see hallucinogen). It occurs in
the cereal-fungus ergot and is
classiÜed as an ergot *alkaloid. LSD
was Ürst synthesized in 1943.
lysine See amino acid.
LUMO
334
l
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sprayed with the reagent, traces of
blood (even old blood) emit a faint
chemoluminescence.
LUMO See lowest unoccupied molecular orbital.
lutetium Symbol Lu. A silvery
metallic element belonging to the
*lanthanoids; a.n. 71; r.a.m. 174.97;
r.d. 9.8404 (20°C); m.p. 1663°C; b.p.
3402°C. Lutetium is the least abundant of the elements and the little
quantities that are available have
been obtained by processing other
metals. There are two natural isotopes, lutetium–175 (stable) and
lutetium–176 (half-life 2.2 × 10
10
years). The element is used as a catalyst. It was Ürst identiÜed by Gerges
Urbain (1872–1938) in 1907.
A
• Information from the WebElements site
lux Symbol lx. The SI unit of illuminance equal to the illumination produced by a luminous Ûux of 1 lumen
distributed uniformly over an area of
1 square metre.
lyate ion The ion formed by removing a hydron from a molecule of
a solvent. In water, for example, the
hydroxide ion (OH
– ) is the lyate ion.
lye See potassium hydroxide.
Lyman series See hydrogen spectrum.
lyonium ion The ion formed by
adding a hydron (H
+ ) to a solvent
molecule. For example, in ethanol,
C 2 H 5 OH 2
+ is the lyonium ion.
lyophilic Having an afÜnity for a
solvent (‘solvent-loving’; if the solvent is water the term hydrophilic is
used). See colloids.
lyophobic Lacking any afÜnity for
a solvent (‘solvent-hating’; if the solvent is water the term hydrophobic is
used). See colloids.
lyotropic mesomorph An
arrangement taken by micelles
formed from surfactant molecules in
concentrated solutions. A lyotropic
mesomorph consists of long cylinders in a fairly close-packed hexagonal arrangement. Lyotropic
mesomorphs are sometimes called
liquid crystalline phases for micelles.
lysergic acid diethylamide (LSD)
A chemical derivative of lysergic acid
that has potent hallucinogenic properties (see hallucinogen). It occurs in
the cereal-fungus ergot and is
classiÜed as an ergot *alkaloid. LSD
was Ürst synthesized in 1943.
lysine See amino acid.
LUMO
334
l
www.AzShimi.ir www.AzShimi.com