Chem 109H Fall08

Be sure that when you draw a unit cell, if you place the 'left' edge against the 'right' edge, they have the same lattice points touching!

For a, b (see below for ion size)

for (c)

For (b)

Try selecting various energy levels at the top of the applet. We have only talked about being in a single energy level at a time - thus deselect an energy level before selecting another one.

Note that this is how you would calculate ENC - Although the nucleus gets MORE positive down the PT, the ENC actually decreases! Not just the compensation part, but actually in it's entirety.

Interesting way to understand wave mechanics.

This reminds me of the video in lecture. However, I really like the way the applet shows how waves work in what looks like a crystal lattice.

As the wave frequency is increased, the wavelength decreases.

Yes - what do you think this will end up meaning for relating color of light to energy of light? What does a long wavelength mean?

1-D Vs. 2-D Waves

Which of these waves was 1D and which 2D?

This is a fairly large PDF file, but it has some good visual information!

Loud sound also produced by resonant frequencies...notice, resonant light waves produce visibly pleasing results while sound waves produce audibly noticable results.

Yes, and resonate frequencies can produce non-pleasing results - the age old "shattering wine glass" which happens when an opera singer hits just the right 'resonating' high pitch!

Which is better? Presumably the tool bar is more powerful but the Diigolet is easier to use. Is that right?

I think that the Digolet is actually easier, and doesn't require an install. The toolbar is more powerful, and the show/hide feature is nice. Try visiting this website to see where a show/hide feature would be nice: http://mashable.com/2006/07/24/diigo-launches-nobody-cares/

Simple, direct tutorial on waves.

We didn't talk about this in class, but it helps explain why some waves can't even be seen moving - like longitudinal waves in the stones during earthquakes!

When a wave is confined to a specific place, only certain wavelengths--those that can fit the space available--are allowed. These allowed waves reflect from the boundaries of the space and the reflection reinforces the original wave (constructive interference). All other wavelengths cancel each other out by destructive interference.

Has anyone determined the pattern in the frequencies for the videos?

On this page: -Propagation -Frequency -Wavelength