1. Ch. 5: Electrons in the Atom

2. In this Chapter… Chapter 5: Electrons in Atoms
5.1: Light and Quantized Energy
5.2: Quantum Theory and the Atom
5.3: Electron Configuration

3. REVIEW: History of the Atom
Dalton Thomson Rutherford
All matter is made of tiny, indivisible atoms
Plum pudding model
Positive nucleus and electrons in empty space around the nucleus 3

4. REVIEW: History of the Atom
Bohr’s model and eventually the Electron Cloud model were developed in part to explain the different colors of light when elements burn 4

5. 5.1 Light and Quantized Energy

6. Light behaves like a wave
A. Wave Nature of Light
Light behaves like a wave

7. A. Wave Nature of Light
Crest – point on the wave with the maximum POSITIVE displacement from the equilibrium position
Trough – point on the wave with the maximum NEGATIVE displacement from the equilibrium position
Wavelength (λ) – distance between crests (or troughs) on a wave
Amplitude (A) – maximum displacement from the undisturbed medium to the top of the crest
Frequency (ʋ) – number of waves per second (Hz or 1/s or s-1)

8. A. Wave Nature of Light
Electromagnetic Radiation – energy with wave-like behavior
2 parts: Electric Field & Magnetic Field

9. A. Wave Nature of Light 3.00 x 108 m/s c = λν
All electromagnetic waves travel at the speed of light (c)
3.00 x 108 m/s
c = λν
c = speed of light (m/s)
λ = wavelength (m)
ν = frequency ( s-1 or Hz)

10. ÷ × A. Wave Nature of Light λ ν PRACTICE: c = λν c
c = speed of light = 3.00 x 108 m/s
λ = wavelength = ???
ν = frequency = 5.10 x 1014 /s
λ = c/ν = 3.00 x 108 m/s ÷ 5.10 x 1014 /s
= 5.88 x m c ÷ λ × ν

11. ÷ × A. Wave Nature of Light λ ν PRACTICE: c = λν c
c = speed of light = 3.00 x 108 m/s
λ = wavelength = x 10-6 m
ν = frequency = ??
ν = c/ λ = 3.00 x 108 m/s ÷ 2.50 x 10-6 m
= 1.20 x 1014 /s c ÷ λ × ν

12. ÷ × A. Wave Nature of Light λ ν PRACTICE: c = λν c c = 3.oo x 108 m/s
Determine the frequency of light
with a wavelength of 675 nm
(hint: convert nm to m first,
then calculate)
c = 3.oo x 108 m/s
λ = 675 nm = _________ m
ν = ?? c ÷ λ × ν

13. B. Electromagnetic Spectrum
Electromagnetic spectrum – the range of wavelengths of electromagnetic radiation
LIGHT: all wavelengths on the spectrum

16. White light is the combination of all the visible colors of light
Visible Light
Red
Orange
Yellow
Green
Blue
Indigo
Violet
high energy
low energy
White light is the combination of all the visible colors of light