Chapter
2
Quizzes:
Self
Activities
Chapter
Cum.
Videos
Movies
Words
Appendix
Summary
Art
Art
Unit 1: The Chemistry of Life
The Chemical Context of Life
Review
Matter consists of
chemical
in
pure
form and in combinations called
.
Four
elements
make up 96% of living matter:
(C),
(H),
(O), and
(N).
Each element is made of a single kind of
. An
atom
is
made
of
,
, and
.
The
number of an
element
is the number of
in the
nucleus.
The
number is the sum of protons plus neutrons.
Electrons occupy different
with different
energy
. The outermost, or
, shell contains
electrons.
A
bond
is the
of a pair of
electrons between different atoms of a
. These bonds are strong and stable.
A
covalent
bond
is the sharing of two pairs of
valence
electrons.
Electronegativity is the attraction of an atom for
. In a
covalent bond the atoms have different
electronegativities
and share the
electrons
.
In an
bond one atom strips
away from other atoms, creating
atoms
called
.
Ionic
compounds are often called
, which may
form
.
Electronegativity can result in weak chemical bonds.
A
bond
forms from the attraction of charged regions of
molecules.
interactions
form when transiently charged regions of molecules attract each other.
Chapter
3
Quizzes:
Self
Activities
Chapter
Cum.
Videos
Movies
Words
Appendix
Summary
Art
Art
Unit 1: The Chemistry of Life
Water and the Fitness of the Environment
Review
is the biological medium here on
Earth.
Water
is a
molecule, and its numerous
bonds result in unique
properties.
Weak bonding of water molecules to each other leads to high
among water molecules. Cohesion at the liquid surface leads to
high
tension.
Van der Waals
forces between water and other molecules lead to
strong
, which can be seen in the
meniscus
in tubes, and in
action
in small tubes.
Water has high
heat, and moderates nearby
and ground
temperatures.
Its high heat of
leads to
cooling of
wet
surfaces.
Solid
water is less
than liquid water and floats, allowing
life
under
frozen
surfaces.
Water is a versatile
and can dissolve
polar
and ionic (hydrophilic)
substances.
Hydrophilic substances too large to dissolve in water can
form
a
, a stable suspension of fine particles in a
liquid,
such as in the
of a cell.
Water can
dissociate
into H
+
(hydrogen) and OH
-
(hydroxide)
.
The
concentration
of these ions is measured on the
scale.
An
has a high concentration of H
+
ions, while a
has a low
concentration.
such as
carbonic
acid minimize changes in pH and consist of an
pair that reversibly combines with hydrogen ions.
precipitation
is caused primarily by the mixing of water vapor and
and
oxides produced by the combustion of
fuels.
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