Transcript Chapter 11: Atomic Orbitals

Section 11.3
Atomic Orbitals
Objectives
1. To learn about the shapes of the s, p and d orbitals
2. To review the energy levels and orbitals of the wave
mechanical model of the atom
3. To learn about electron spin
Section 11.3
Atomic Orbitals
A. The Hydrogen Orbitals
• Orbitals do not have sharp boundaries.
90% boundary
Section 11.3
Atomic Orbitals
A. The Hydrogen Orbitals
Hydrogen Energy Levels
• Hydrogen has discrete energy
levels.
• Called principal energy
levels (electron shells)
• Labeled with whole numbers
• Energy is related to 1/n2
• En = E1/n2
• Energy levels are closer
together the further they are
from the nucleus
Section 11.3
Atomic Orbitals
A. The Hydrogen Orbitals
Hydrogen Energy Levels
• Each principal energy level is divided into sublevels.
– Labeled with numbers and letters
– Indicate the shape of the orbital
Section 11.3
Atomic Orbitals
Orbital Designations
Section 11.3
Atomic Orbitals
Orbitals Define the Periodic Table
Section 11.3
Atomic Orbitals
A. The Hydrogen Orbitals
Hydrogen Energy Levels
• The s and p types of sublevel
Section 11.3
Atomic Orbitals
Representation of s, p, d atomic orbitals
Section 11.3
Atomic Orbitals
A. The Hydrogen Orbitals
Hydrogen Orbitals
• Why does an H atom have so many orbitals and only 1
electron?
– An orbital is a potential space for an electron.
– Atoms can have many potential orbitals.
• s, p, d, f orbitals named for sharp, principal, diffuse and
fundamental lines on spectra. Further orbitals designated
alphabetically
Section 11.3
Atomic Orbitals
s
p
d
f
f
f
g
g
g
d
g
Section 11.3
Atomic Orbitals
B. The Wave Mechanical Model: Further Development
Electron Spin
• Close examination of spectra revealed doublets
• Need one more property to determine how electrons
are arranged
• Spin – electron modeled as a spinning like a top
• Spin is the basis of magnetism
Section 11.3
Atomic Orbitals
B. The Wave Mechanical Model: Further Development
Pauli Exclusion Principle
• Pauli Exclusion Principle (Wolfgang Pauli 1925) - an
atomic orbital can hold a maximum of 2 electrons and
those 2 electrons must have opposite spins
• When an orbital contains two electrons (of opposite
spin) it is said to be full
What are the four descriptors that define an energy
level / electron’s position in an atom?