Chemistry Reference
In-Depth Information
chiral molecule
An
asymmetric molecule
that cannot be superimposed on its mirror
image.
chirality
The property of an object that cannot be superimposed on its mirror
image; see
isomerism
,
optical
.
chloride
A
chemical compound
that contains negatively charged chloride (Cl
−
)
ions
.
chromatin
One of the two portions of the
nuclei
of living
cells
(the other is
achro-
matin
, in which chromatin is embedded) that make up the chromosomes; it con-
sists of a mixture of threadlike
proteins
and
DNA
.
chromatography
Generic name for chemical techniques for separating and charac-
terizing the components of a
mixture
.
chromatography, gas
A
chromatographic
technique applicable to gases or liquids that
can be brought into the gaseous state.
chromatography, gas-mass spectrometry
A technique of
chemical analysis
that com-
bines
gas chromatography
and
mass spectrometry
.
chromophore
From the Greek word for “color bringer;” a
molecule
or group of
atoms
that absorbs part of
visible white light
and, therefore, imparts
color
to the
substance
of which it is a component or to which it is attached.
chromosome
A threadlike structure made up of a linear, end-to-end sequence of
genes
in the nucleus of the
cell
, which transmits the
genetic code
of living organ-
isms; see
chromatin
.
chronometric date
See
absolute date
.
chronometric dating
See
dating absolute
.
cinnabar
A mineral composed of mercury sulfide, used as a red
pigment
and main
ore
of mercury.
cinder
A mixture of
slag
and
charcoal
formed during
smelting
operations.
cire perdue casting
The French name for the
lost wax casting
method.
classical methods of chemical analysis
See
analysis
,
gravimetric
and
analysis
,
volumetric
.
clastic
A
rock
or
sediment
made up mainly of broken fragments of
minerals
or older
rocks that have been transported some distance from their places of origin.
clay
(1)
Mineral
particles smaller than 0.004 mm in diameter; (2) a
sediment
com-
posed of
clay minerals
.
clay, primary
Clay
formed in situ by the natural
weathering
of
igneous rocks
; also
called
residual clay
; see
secondary clay
.
clay, secondary
A natural
clay
that was moved by such natural agencies as water
streams or wind from its place of origin, before it became deposited at a site; also
called
sedimentary clay
.
clay body
A mixture of
clay
and
minerals
used for making
ceramic
objects.
clay minerals
Fine-particled
sediments
, such as
kaolinite
,
montmorillonite
, and
hal-
loisite
, composed of aluminum silicate
minerals
derived from the
chemical weather-
ing
of
felspathic rocks
.
