Section 11.3
Atomic Orbitals
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
Objectives
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 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
Hydrogen Energy Levels
Section 11.3
Atomic Orbitals
A. The Hydrogen Orbitals
• Each principal energy level is divided into sublevels.
Hydrogen Energy Levels
– 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
• The s and p types of sublevel
Hydrogen Energy Levels
Section 11.3
Atomic Orbitals
Representation of s, p, d atomic orbitals
Section 11.3
Atomic Orbitals
A. The 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
Hydrogen Orbitals
Section 11.3
Atomic Orbitals
g g gg
f ff
s p d d
Section 11.3
Atomic Orbitals
• 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
B. The Wave Mechanical Model: Further Development
Electron Spin
Section 11.3
Atomic Orbitals
• 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
B. The Wave Mechanical Model: Further Development
Pauli Exclusion Principle
What are the four descriptors that define an energy level / electron’s position in an atom?
