From Waves to Orbitals

Written by Administrator Thursday, 02 April 2009 17:04

Chladni Plate

If you have already gone through our Wave Tutorial, then you've learned about wavelength, frequency, and standing waves within a circular boundary. That tutorial concluded with a video of the 

Chladni Plate in use. To the left you can see this video once again. As the sound waves create a standing wave pattern within the circular plate, the grains of sand get shaken into a discernible pattern. 

As the frequency increases, you'll notice that the sound gets to be a higher pitch (if you have the sound turned on), and that the circular rings of sand get more closely spaced - and indeed you'll notice that there are more of them in the same area! 

The area where the sand collects is the area where the plate is vibrating the least. Thus, as can be seen in the next video, the standing waves create stationary nodes where there is little motion. This wave demonstrator shows a standing wave patter in only 1 dimension (as opposed to the 2 dimensions in the Chladni plate). 

On the Chladni plate sand collects in the places where there is a stationary region between two vibrating regions. Such a place is called a node. Nodes in the wave demonstrator have the same property. How many nodes does this wave demonstrator have?

Suppose that the waves in the wave demonstrator were associated with an electron in a confined space. In order to create a standing wave with 4 nodes, would you have to increases or decrease the energy of the electron?