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44 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
5
The modern atomic model De Broglie’s work, followed by
the work of Werner Heisenberg and Irwin Schrödinger, led to the
modern quantum mechanical model of the atom. This model may
be summarized as follows.
1. Electrons occupy the space surrounding the
nucleus and can exist in several discrete principal energy levels, each designated by one of the
principal quantum numbers (n) that are the
integers 1, 2, 3, 4, and so on.
2. Electrons in successively higher principal
energy levels have greater energy.
3. Because of interactions among electrons, each
principal energy level consists of energy sublevels that have slightly different energy values.
These sublevels are designated by the letters s,
p, d, and f in order of increasing energy. The
first principal energy level (n ϭ 1) has only one
sublevel (s). The second principal energy level
(n ϭ 2) consists of two sublevels (s and p). The
third principal energy level consists of three
sublevels (s, p, and d), and the fourth consists of
four sublevels (s, p, d, and f).
4. Each energy sublevel consists of one or more
orbitals, each of which can contain two electrons.
An s sublevel has one orbital; a p sublevel has
three orbitals; a d sublevel has five orbitals; and
an f sublevel has seven orbitals. All of the
orbitals in the same sublevel are of equal energy.
5. Atomic orbitals are regions of space in which
there is a high probability (90 percent) of finding
an electron. Except for s orbitals, the orbitals are
not spherical in shape. Unlike Bohr’s atomic
model, electrons are not in specifically defined
orbits. Instead, they can be anywhere within the
orbital, and there is a 10 percent chance that the
electron will be located outside the orbital.
▲
44 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
5
The modern atomic model De Broglie’s work, followed by
the work of Werner Heisenberg and Irwin Schrödinger, led to the
modern quantum mechanical model of the atom. This model may
be summarized as follows.
1. Electrons occupy the space surrounding the
nucleus and can exist in several discrete principal energy levels, each designated by one of the
principal quantum numbers (n) that are the
integers 1, 2, 3, 4, and so on.
2. Electrons in successively higher principal
energy levels have greater energy.
3. Because of interactions among electrons, each
principal energy level consists of energy sublevels that have slightly different energy values.
These sublevels are designated by the letters s,
p, d, and f in order of increasing energy. The
first principal energy level (n ϭ 1) has only one
sublevel (s). The second principal energy level
(n ϭ 2) consists of two sublevels (s and p). The
third principal energy level consists of three
sublevels (s, p, and d), and the fourth consists of
four sublevels (s, p, d, and f).
4. Each energy sublevel consists of one or more
orbitals, each of which can contain two electrons.
An s sublevel has one orbital; a p sublevel has
three orbitals; a d sublevel has five orbitals; and
an f sublevel has seven orbitals. All of the
orbitals in the same sublevel are of equal energy.
5. Atomic orbitals are regions of space in which
there is a high probability (90 percent) of finding
an electron. Except for s orbitals, the orbitals are
not spherical in shape. Unlike Bohr’s atomic
model, electrons are not in specifically defined
orbits. Instead, they can be anywhere within the
orbital, and there is a 10 percent chance that the
electron will be located outside the orbital.
▲