1. Wave-Particle Duality
Electronic structure (electron configurations)
- base for many chemistry concepts ex: molecular geometry & chemical reactivity.
Electromagnetic radiation is the probe used to obtain knowledge of the electronic structure.

2. Electromagnetic Radiation
Short Wavelength =High Frequency = High ENERGY
Long Wavelength = Low Frequency = Low ENERGY
Electromagnetic radiation propagates through space as a wave moving at the speed of light.

3. c = 
WAVE MODEL
C = speed of light (3.00 x 108 m/s)
 = wavelength, (m); distance between 2 peaks
 = frequency, (hertz = hz, sec-1); # peaks per time
Is this a direct or inverse relationship? ___________
INVERSE
Direct = DDSS Direct, Divide, Same variable direction, Straight line

4. What is the speed at which radio waves travel?
3 x 108 m/s
What is the speed at which radio waves travel?
Which one travels faster red or blue light?
Same Speed = 3 x 108 m/s
Which has more energy red or blue light?
BLUE = higher frequency

5. Constructive Interference
Waves - SYNCHRONIZED -ENLARGED wave result bright bands
Destructive Interference
Waves -NOT SYNCHRONIZED - waves cancel out result black/gray bands

7. De Broglie’s Equation
Broglie’s stated that an object in motion behaves as both particles & waves, just as light does.
Electrons are WAVES in FIXED LOCATIONS which means they are QUANTIZED (quantity) wavelengths. 7

8. Sizes of s orbitals
Orbitals of the same shape grow larger as n increases…
Nodes are regions of low probability within an orbital.

9. Heisenberg Uncertainty Principle
“One cannot simultaneously determine both the position and momentum of an electron.
Schrodinger (CAT) Wave Equation
Equation for probability of a single electron being found along a single axis (x-axis)
Schrodinger wave equation & Heisenberg Uncertainty principle provided the framework for the QUANTUM THEORY!

10. Particle Model (Planck’s Equation)
Realized hot object do NOT emit electromagnetic energy continuously but as energy in small specific amounts called quanta (wave)
Particle Model (Planck’s Equation)
Ephoton= h
E photon= Energy (Joules = kg·m2/s2)
h = Planck’s constant (6.626 x J·s)
 = frequency (hertz = hz, sec-1)
Energy is directly related to FREQUENCY.
What is photon? – particle of light

11. Ground State Excited State
ABSORPTION
Ground State Excited State
EMISSION
Camp Fire
Hot Metal

12. Spectroscopic analysis : wavelength analysis
Continuous Emission Spectrum: produces all colors
Bright Line emission spectrum: produce specific wavelengths
** Wavelength analysis is a FINGERPRINT for element.

13. SUMMARY Wave Theory Particle Theory Formula: c =  Formula E = h
Measurable characteristics - Frequency & wavelength
Light can interfere and diffract (bend)
Particle Theory
Formula E = h
Light when it absorbs/emits by matter ) photoelectric effect (shiny metal) ) Absorption of Light by HOT objects ) Line-Emission Spectra of elements

14. Einstein’s Equation E = mc2
Light has mass!!
Light is a particle!!
It both a wave-particle called PHOTON (zero mass carrying a quantum of energy)
Einstein’s Equation E = mc2

15. CoMbInInG FoRmUlA’s Wave Equation: c = ln  n = c/l
n = c/l inserted into
Planck’s (Particle) Equation E = hn
E = (hc)/l
Einstein’s Equation E = mc2
Combine (hc)/l = mc (hc) = mc2 l l = (hc) / (mc2) …”c” cancels out…..
l = h/mc or m = h/ lc note: c = speed = velocity
What does this MEAN?
Anything that has both MASS and VELOCITY (movement) has a corresponding WAVELENGTH!

17. Observed Spectra of Elements

18. Wave-Particle Duality
JJ Thomson won the Nobel prize for describing the electron as a particle.
The electron is a particle!
The electron is an energy wave!
George Thomson won the Nobel prize for describing the wave-like nature of the electron.