1. Ap Chemistry Due Next Class: Reading 6.5-6.8 & Proof of reading
Hand Warmer LaB
Up Coming Due Dates:
MC Ch. 6 Due… DON’T PROCRASTINATE!

2. Hand Warmer Lab Report Requirements
Objective
Materials
General Procedure
Data
Questions
Proposal & Justification

3. Warm Up
Most missed on Ch. 5 MC

4. Lecture

5. Electronic Structure
The distance between corresponding points on adjacent waves is the wavelength ().
The number of waves passing a given point per unit of time is the frequency ().

6. Electromagnetic Radiation
You listen to in your car
Cancer Radiation Therapy
Cooks your food
All electromagnetic radiation travels at the speed of light (c)
3.00  108 m/s.
c = 
Careful! Wavelength is in nm and c is in m/s
This is what we will mainly be looking at

7. The Photoelectric Effect
Energy comes in packets called quanta (singular: quantum).
Einstein used quanta to explain the photoelectric effect.
Each metal has a different energy at which it ejects electrons. At lower energy, electrons are not emitted.
E = h
Planck’s constant
Frequency

8. The energy of a photon divided by its frequency equals
c, the speed of light.
h, Planck’s constant.
Avogadro’s Number.
4.184.
Answer: b

9. Continuous vs. Line Spectra
Continuous spectrum (the “rainbow” is from white light
Line spectrum- Discrete wavelengths is observed. Each element has a unique line spectrum.
Each element is QUANTIZED!

10. Bohr + Planck’s Ideas =
Electrons can only occupy certain orbits (corresponding to certain energies).
Electrons have specific, “allowed” energies
Energy is only absorbed or emitted to move an electron from one “allowed” energy state to another;
E = h

11. The lowest energy state of a hydrogen atom is called its _______ state.
bottom
ground
fundamental
original
Answer: b

12. Limitations of the Bohr Model
It only works for hydrogen!
Classical physics would result in an electron falling into the positively charged nucleus. Bohr simply assumed it would not!
Circular motion is not wave-like in nature.

13. Important things of the Bohr Model
Nobel prize for me!
Electrons exist only in certain discrete energy levels.
Energy is involved in the transition of an electron from one level to another.

14. The Uncertainty Principle
Heisenberg Uncertainty Principle:
The more precisely the momentum of a particle is known, the less precisely is its position is known…
Nobel prize for me too!
(x) (mv)  h 4

15. Work time
Practice
Lab Work Time due next class!