The Electron Cloud

1
Chapter 5

• The Electron Cloud

2
Billiard Ball Model
3
Plum Pudding Model

• positive sphere (pudding) with negative electrons
  (plums) dispersed throughout.

4
Rutherfords Nuclear Atom
5
Chadwicks Revision
6
Bohr Model

• Electrons move in orbits of definite energies.

7
The Heisenberg Uncertainty Principle
8
The Heisenberg Uncertainty Principle

• It is impossible to determine the exact position
  (location) and momentum (velocity) of an object
  at the same time.

9
How do we see something?
10
How do we see something?
Smack
11
(No Transcript)
12
(No Transcript)
13
The Heisenberg Uncertainty Principle

• To observe something we must bounce something off
  it. (example light photons).
• In our macroscopic world the effect of photons is
  insignificant but for subatomic particles this is
  not the case.

14
The Heisenberg Uncertainty Principle

• Photons that hit subatomic particles (electrons)
  cause them to move significantly.
• The more energy we hit the electron with the more
  we change its momentum (velocity).

15
What energy should I use to see the electron?
Alpha beta gamma omega and
aura
aura
omega
Alpha beta
Alpha beta gamma omega and
aura
alpha
Alpha beta gamma omega
16
The Heisenberg Uncertainty Principle

• It is impossible to determine the exact position
  (location) and momentum (velocity) of an object
  at the same time.

17
The higher energy wave gives a better estimate of
location but changes the momentum (velocity)
more. The lower energy wave will cause less of a
momentum change but is a poor estimate of
location.
Alpha beta gamma omega and
aura
aura
omega
Alpha beta
Alpha beta gamma omega and
aura
alpha
Alpha beta gamma omega
18
Electron Cloud Model
19
Electron Cloud Model

• Based on probability

20
Electron Cloud Model

• The electron cloud is a cloud of negative charge
  surrounding the nucleus that shows areas where an
  electron is likely to be found.

21
Electron Cloud Model

• The location of the electrons depends upon their
  energy which places them into a certain region of
  the electron cloud.
• Electrons with less energy are found closer to
  the nucleus.

22
Homework

• Chapter 5 Worksheet 1 (not due tomorrow).
• (should be able to answer question 1 - 4.)