Chemistry Reference
In-Depth Information
(a)
(b)
(c)
Figure 20.2
Tetrahedral Nature of the Carbon Atom
(a) A tetrahedron has four triangular sides (including the base). (b) The carbon atom of is typical of carbon atoms in
alkanes. (c) The tetrahedral nature of the carbon atom is apparent in that its bonds with four hydrogen atoms point toward the
corners of a tetrahedron. (Model courtesy of Molecular Models Co.)
CH
4
Section 20.4.) Moreover, the atoms can bond in different ways (see Section 20.2),
which greatly increases the number of possible compounds.
When a carbon atom is connected to four other atoms with single bonds,
those bonds are oriented toward the corners of a tetrahedron (Figure 20.2).
The angle between any two of the bonds is A chain of such atoms
in a hydrocarbon can assume a zigzag shape (see Figure 20.1). Organic
molecules are usually represented in one of six different ways (Figure 20.3).
109.5°.
Representations
Figure 20.3
of Butane
(a) Space-filling model, shown
with blue carbon atoms and white
hydrogen atoms. (Image from
HyperChem software, © Autodesk,
Inc.) (b) Ball-and-stick model, with
black carbon atoms and white
hydrogen atoms. (Model courtesy of
Molecular Models Co.) (c) Structural
formula indicating actual bond
angles. (d) “Two-dimensional”
structural formula. (e) Line formula.
(f ) Molecular formula.
Condensed formulas are
introduced on page 520.
(a)
(b)
HHH
H
H
W
H
W
H
W
H
W
H
C
C
H
±
C
±
C
±
C
±
C
±
H
C
C
H
H
H
H
H
HHH
H
(c)
(d)
CH
3
CH
2
CH
2
CH
3
C
4
H
10
(e)
(f)
