Preview - Charge Interactions Chem/Phys

One Conductor -- Electron Behavior

During our sticky tape lab, we investigated the behavior of B and T tapes as well as several other types of objects.  Let's take a look at a simulation that can help us think about what individual charges are doing on metal conductors (note: we will talk about how B and T tapes might behave a bit later).

To run the simulation, adjust the settings for shape, size, and number of electrons,  then click "setup" and then click "go". If you need to change the speed of the simulation, pull the slider on the bar labeled "ticks" at the top. When you're ready to start a new trial, again adjust settings, click setup, and go.

 

Questions

Please answer the questions below.

This simulation shows a large metal conductor (in grey) that can be given many extra electrons. Play with the simulation for a few minutes and write down your observations.

Talk with a neighbor and brainstorm what rules seem to be guiding the electrons' behavior/movement. Record your answers.

Do you notice any difference between how the electrons move for the square conductor as compared to the circle conductor? Why do you think the electrons are behaving in this way?

Hint: Try this with a relatively small number of charges.

Set the conductor to be a circle, and then let the simulation run for a while. You can move the "ticks" slider to the right to make it run faster. What do you notice if you let the simulation run for a very long time?

Now run the simulation several times (with either shape, but don't change it during these trials), keeping the "n-electrons" constant, but changing the "side-length" to different values several times. Record your observations about how the electrons behave as the side-length changes.

Now run the simulation several times (with either shape, but don't change it during these trials), keeping the side length constant but varying the number of electrons. What do you notice about what happens as the number of electrons changes?

Throughout the questions above, you should have noticed that the electrons spread out and move to the surface of the conductor.  Why do you think this occurs? Additionally, summarize what patterns you observe when shape and electron number changes.

Any computer simulation is written with a number of assumptions and simplifications in mind. Can you think of ways that this simulation does not accurately represent what happens in real life in a metal?

Hint: draw on your Chemistry knowledge

Now click on the "NetLogo Code" tab below the simulation.  Can you figure out a way to change the color of the conductor from grey to red? In order to test your solution, you will need to click the button, "Recompile Code."

Hint: you can type Ctrl-F to find all the places in the code where the word "grey" is used.  Maybe that has something to do with the color used? :)

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.