1. c = speed of light (ms-1, constant)
Electromagnetic Radiation
 c/
 = wavelength (m)
 = frequency (Hz = s-1)
c = speed of light (ms-1, constant)
c = 3.00*108 ms-1
we say: 1/
Point A

2. Electromagnetic Spectrum
When do we see white?
All wavelengths of the visible
spectrum (ROYGBV) and
equal amounts of RGB
(look at your TV) hc  1 
E = ;
E 
saunders 7-4

3. The Photoelectric Effect
Exp: A metal plate is exposed to electromagnetic radiation (Light)
and a detector is used to determine if electrons are ejected from
the metal.
Classical Theory states that even if low energy light is used the
electrons should eventually be ejected. Exp. results did not agree.
Exp. results showed that only light of sufficient energy would eject
electrons from the metal and each metal required a different energy.
Albert Einstein - explained this result using Planck’s idea that light also
behaves like particles (photons) and that each particle
has a specific (quantum) amount of energy.
Intensity of light - # of photons striking a given area of
the plate per second

4. Atomic Spectrum Emission spectrum Balmer Series 1 1 R=rydberg
pg. 202 Enrichment 1
n12 1
n22
R=rydberg
constant
n1 < n2

5. Bohr Model
n=3
n=2
n=1

6. Wave Nature of Electronsh mv
 =
Louis de broglie
saunders 7-8

7. Heisenberg Uncertainty Principle
It is impossible to determine accurately both the momentum and
the position of a very small particle (electron) simultaneously

8. Quantum Mechanics
Atoms and molecules can exist only in certain energy states (quantized energy levels)
When they change their state they absorb or emit radiation (light/photons) E = hc/
Allowed energy states are described by 4 quantum numbers

9. Principle Quantum Number - n = 1, 2, 3 ....
Describes the main energy level and the extent of the orbital
Angular Momentum Quantum Number - l = 0, 1, 2, ... , (n - 1)
Describes the shape of the orbital
l = 0 s orbital, l = 1 p orbital, l = 2 d orbital, l = 3 f orbital, l = 4 g orbital, l = 5 h orbital .....
Magnetic Quantum Number - ml = -l, -l+1 , ... , 0 , ... , l-1 , l
Describes the orientation of each orbital
Spin Quantum Number - ms - ±(1/2)
Describes the spin of the electron in each orbital