Download Chapter 13 – Electrons in Atoms

Chapter 13 – Electrons in
Atoms
13.1
13.2
13.3
Models of the Atom
Electron Arrangement in
Atoms
Physics and the Quantum
Mechanical Model
13.1

Models of the Atom
The Evolution of
Atomic Models

Dalton


Thomson


Gold-foil
Bohr


Plum pudding
Rutherford


Solid, indivisible
Planetary
Quantum
Mechanical

Probability
13.2
Electron Arrangement in
Atoms

Electron Configurations

Fortunately, we can “predict” where these electrons are
most likely to be found and represent these locations
with simple notation by following some simple rules:

Aufbau Principle
 Electrons fill lowest energy levels first.

Pauli Exclusion Principle
 Only two electrons can be in an orbital at once.

Hund’s Rule
 Each orbital must have at least one electron in it before
getting a second.

Example:
O, Atomic # 8 – 1s22s22p4
 Configuration vs. Notation

Examples:
13.3
Physics and the Quantum
Mechanical Model

Light and
Atomic Spectra

To fully
understand
quantum
mechanics you
must
understand the
nature of light
and waves.
13.3
Physics and the Quantum
Mechanical Model (cont.)

Light and Atomic Spectra (cont.)

Light is an electromagnetic wave that when passed through a
prism separates into a spectrum of colors:
13.3
Physics and the Quantum
Mechanical Model (cont.)

Light and Atomic Spectra (cont.)

Atoms/elements emit light when the electrons are
excited (first absorb then emit energy in the form of
light) at specific frequencies.
Chapter 13 Assignment

CPQ 1 pg. 386 #27,28,29,30,31,33