2. What is the chance of finding an
electron in the nucleus?
3. QUANTUM MECHANICAL MODEL OF ATOM STATES
THAT:
• Electrons are NOT in circular orbits around nucleus.
• Electrons are in a 3-D region around the nucleus called
atomic orbitals.
• The atomic orbital describes the probable location of the
electron.
4.
5. Where does this model come from?
A quick history.
• Louis de Broglie:
Electrons behave with
wave and particle
properties at the same
time.
6. • Werner Heisenberg: It is impossible to know both the
position and velocity of an electron simultaneously.
• *Heisenberg's Uncertainty Principle
7. Erwin Schrodinger: Refined the
wave-particle theory proposed by de
Broglie. Developed an equation that
treated an electron like a wave and
predicted the probable location of an
electron around the nucleus called the
atomic orbital.
9. The Quantum Mechanical Model
–The quantum model determines the
allowed energies an electron can
have and how likely it is to find the
electron in various locations around
the nucleus.
5.1
10. The Quantum Mechanical Model
• The probability of finding an electron
within a certain volume of space
surrounding the nucleus can be
represented as a fuzzy cloud.
– The cloud is more dense where the
probability of finding the electron
is high.
11. Atomic Orbitals
• (fuzzy cloud) = An atomic orbital is often thought of as a
region of space in which there is a high probability of
finding an electron.
5.1
21. Shells and Orbitals and Atomic Structure
•Shells of
an atom
contain a
number of
stacked
orbitals
1
2
3
4
s p d
f
22. 1st and 2nd level s-orbitals
and the p-orbitals all together.
23. Atomic Orbitals
5.1
• Different atomic orbitals are denoted by letters. The
s orbitals are spherical, and p orbitals are dumbbell-
shaped.
• Four of the five d orbitals have the same shape but
different orientations in space.
25. Atomic Orbitals
• The numbers and kinds of atomic orbitals
depend on the energy sublevel.
5.1
Energy Level,
n
# of sublevels Letter of
sublevels
# of orbitals
per sublevel
# of electrons
in each
orbital
Total
electrons in
energy level
26. Atomic Orbitals
• The numbers and kinds of atomic orbitals
depend on the energy sublevel.
5.1
Energy Level,
n
# of sublevels Letter of
sublevels
# of orbitals
per sublevel
# of electrons
in each
orbital
Total
electrons in
energy level
1 1 s 1 2 2
2 2
s
p
1
3
2
6
8
3 3
s
p
d
1
3
5
2
6
10
18
4
4
s
p
d
f
1
3
5
7
2
6
10
14
32
27. The quantum mechanical model describes the probable location of
electrons in atoms by describing:
• -Principal energy level/Principal quantum number (n)
• -Energy sublevel/Angular momentum quantum number (l)
• -Orbital (in each sublevel)/Magnetic quantum number (ml)
• -Spin/Spin quantum number (ms)