1. Light and the electron
Quest continues to discover the structure of atom and how electrons are arranged within atoms.

2. Wave Nature of Light
Electromagnetic radiation – form of energy exhibiting wave-like behavior
Ex. Visible light

3. Wavelength (λ)
Distance between adjacent peaks in a wave. Measured in meters.

4. Speed of light (c) Light travels at 186,000 mi/s 3.00 x 108 m/s
c = 3.00 x 108 m/s

5. Frequency (Ʋ) Number of peaks which pass a point per second.
Ʋ = 1/s (Hz)

6. Wavelength vs. Frequency

7. Putting it together c = λƲ 3.00 x 108 m/s = λƲ
Pg. 121 practice problems 1-4

8. Electromagetic radiation (light)
To microwave

9. Particle Nature of Light
Wave nature of light didn’t explain many important aspects – Why heated objects emit only certain frequencies of light at given temp.?
Quantum concept – heated objects emitting different frequencies of light. Energy emitted corresponds to certain Ʋ & λ
Quantum- minimum amount of energy that can be gained or lost by an atom

10. Max Planck
Energy of quantum is related to the frequency of the emitted radiation
Equantum = hƲ
E = energy
Ʋ = ?
h (Planck’s constant) = x 10–34 J · s
Greater the frequency, greater the energy – directly proportional
Pg. 124 practice problems 5,6

11. Atomic Emission Spectra – light produced in glowing neon signs
Pass energy through tube filled with gas
Causes electrons to absorb energy & become excited
As unstable, excited electrons lose energy and spiral towards the nucleus they give off energy that corresponds with certain frequencies of light
When emitted light is passed through a prism→ atomic emission spectra
Each atom’s atomic emission spectrum is unique and can be used to determine if that element is part of an unknown compound. Pg. 126

12. Bohr e-

13. Bohr e-

14. Bohr e-

15. Bohr e-

16. Bohr e-

17. Hydrogen spectrum