Chapter 8: Electronic Structure and Periodic Properties

Orbital Energies For Single Electron Systems

Penetration and Shielding

Orbital Energies

Electron Configurations The Aufbau process (building up): Electrons will always populate the lowest energy state available. We will use several “rules”, plus our knowledge of electron orbitals to identify the electronic configuration of any atom

The Pauli exclusion principle No two electrons can have all four quantum numbers alike. Hund’s rule Populate all degenerate orbitals (orbitals of the same energy) with a single electron before putting a second electron in any orbital. There are several exceptions to this rule. Electron Configurations

Orbital Filling Because of electron shielding, orbital energies are usually ordered as shown above

The Electronic Configuration of Carbon

The Electronic Configuration of N – Ne

Filling the d Orbitals

Classifying the Elements When the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically.

Alkali MetalsAlkaline EarthsTransition MetalsHalogensNoble Gases Lanthanides and Actinides Main Group

Electron Configurations and the Periodic Table

The Sizes of Atoms and Ions

Radii of Cations

Radii of Anions

Atomic and Ionic Radii

Electron Affinity

Periodic Properties of the Elements

Trends in Physical Properties

Trends in Physical Properties