1. Electrons in Atoms 13.3 Physics and the Quantum Mechanical Model
13.1 Models of the Atom
Atomic orbitals
13.2 Electron Arrangement in Atoms

2. Physics in Chemistry Speed of light, c = 3 x 108 m/s c =  c = 
 = wavelength (m)
“lambda” = 
 = frequency (Hz) (Hertz = s-1)
Also  = frequency
“nu” = 
Electromagnetic spectrum p. 373

4. Atomic emission spectra =
Group of wavelengths of energy emitted by electrons falling down to lower energy levels after being excited
Unique for each element
Ground state vs. Excited state
E = h
E = energy (J) (Joule)
Planck’s constant, h = x Js
 = frequency (Hz)
Photoelectric effect =
Metals eject electrons when light shines on them
Proves the particle concept of the dual
wave-particle behavior of light

5. Example: A popular radio station broadcasts with a frequency of 94
Example: A popular radio station broadcasts with a frequency of 94.7 MHz. What is the wavelength of the broadcast?  = 94.7 MHz = 94.7 x 106 Hz  = ? c =   = c /   = (3 x 108 m/s) / (94.7 x 106 Hz)  = ?

6. deBroglie’s equation =
Calculate the wavelength of a moving particle, like an electron
 = h / mv
 = wavelength (m)
h = Planck’s constant (Js)
m = mass (g)
v = velocity (m/s)
Heisenberg Uncertainty Principle =
You cannot know both the velocity (speed) and position (location) of a particle at the same time