What we've done so far:

Monday, September 12
Wednesday, September 14
Friday, September 16
Monday, September 19
Wednesday, September 21
Friday, September 23
Monday, September 26
Wednesday, September 28
Friday, September 30
  

Monday, September 12
Intro to Chemistry 201!  We looked over the Course Information Sheet. You can print this off when you logon to the Desire2Learn site:  click here to logon.


Wednesday, September 14
We clarified info from the Course Information Sheet and just started a little information about the nature of light.  I will recap for Friday's class and include more in Friday's entry!


Friday, September 16
To understand Atomic Structure, we started by understanding the the nature of light: 7.1  From Classical Physics to Quantum Chemistry
We discussed Light as a wave, and its properties, along with the classification of electromagnetic radiation.
SKILL: convert between wavelength, frequency

We talked about Max Planck and his revolutionary idea.

Key words: continuous vs. quantized
SKILL: determine the energy of a photon

7.2  The Photoelectric Effect
IMPORTANT: it is the frequency of light that matters, not the intensity or brightness - pole vaulter analogy: if the pole is too short, you can bash into wall hard or have a bunch of vaulters, but you still won't get over the wall
Dual Nature of Light: behaves as both a wave and a particle and exhibits properties of both


de Broglie's equation is important as matter also has wave properties - we will return to this idea for electrons in an atom

SKILL: determine the wavelength of matter

Monday, September 19
X-Ray Diffraction uses the wave properties of light (X-rays) to "look" at the positions of atoms in molecules or ions when crystallised.

We looked Atomic Spectrum of Hydrogen.

Key words: (Fig 7.6) continuous spectrum vs. line spectrum: emission and absorption
The full emission spectrum of hydrogen includes lines outside of the visible range.
REMEMBER:  The light observed is emitted as the electron in the H atom undergoes a transition from a higher energy level to a lower one.
For the sections covered so far - Exercises from Chang: 7.8, 7.12, 7.18, 7.25, 7.40
We will see some more examples of emission in Demo 1 and in Experiment 2.

We started talking about some of the implications of 7.3 Bohr's Theory of the Hydrogen Atom
More on this next day!
 
Wednesday, September 21
We continued discussing 7.3.
Definition: The lowest energy state is called the ground state
SKILL: determine energy levels, or transitions between levels
Convention: n=infinity is zero, so energy levels are negative
Exercise:  32

Better theory uses 7.4 The Dual Nature of the Electron: The important thing here is to remember that electrons have wave properties.  In the atom, the electron is bound to the nucleus as a standing wave.  This is used in the mathematical treatment of wave mechanics.
7.5 Quantum Mechanics 

The take home message of this model - since we will not worry about the math in this course - we have energy levels in this model as well.

The energy levels are calculated and generate 3D functions - more on this next class.

Where is the electron in an orbital?  Unanswerable question, Heisenberg uncertainty principle


Friday, September 23
So, how do we describe the electron in the H atom?

By its energy and by a Statistical description: we can't know for sure where it is, but we can say where it is likely to be - probability.


When an electron is in a specific orbital, we know 2 important things:
1.  where the electron is likely to be
2.  what energy the electron has

To label atomic orbitals, we covered 7.6 Quantum Numbers.  There are rules associated with these numbers.  The set of quantum numbers tells us about the size, shape and orientation of an orbital.

We had DEMO 1!!!!  Info about Demonstration #1 can also be found in D2L
Emission (Atomic Spectra)
Remember, an atom in an excited state can emit light of specific wavelength when falling back to the ground state
1. Discharge tubes containing selected noble gases:

2. Flame tests: in expt 2, you’ll do your own examples

For both of these parts, if we passed the light through a prism, we would see a line spectrum!


Monday, September 26
We introduced the rules for quantum numbers. Exercises: 56, 60, 66
SKILL: given a set of quantum numbers, determine if the numbers are valid, and if so, label the orbitals
SKILL: given a shell or subshell,  determine the quantum numbers for all the orbitals (or give the number of orbitals)
SKILL: given an orbital designation, determine the quantum numbers

REMEMBER: All orbital shapes for H atom come from mathematical functions
We started to look at the way chemists visualise 7.7 Atomic Orbitals (or AOs)

Convention: relative orbital size based on 90% of the total electron probability

Wednesday, September 28
Some quantum number homework: answer.

We continued discussing 7.7 Atomic Orbitals, for s orbitals and looked at the energy levels in the H atom.

Definition: all energies are the same for degenerate orbitals.
REMEMBER: All orbital shapes for H atom come from mathematical functions

We looked more carefully at the 1s, 2s, and 3s orbitals.  The overlapping radial probability diagram showed the nodes of the 2s, and 3s orbitals.

IMPORTANT An electron in 3s would be farther away (most of the time) than an electron in 1s, but the 3s electron  would ALWAYS have more energy than the 1s electron.


Friday, September 30
We drew p orbitals and talked about their shapes and energies.
Then we drew d orbitals and talked about their shapes and energies.

Demo 2 - a preview of the next chapter!