A New Model Course in Applied
One student, Mark, clearly states his point of view, while the others listen and comment on (think along with) his ideas.
Mark clearly presents two ideas:
Mark's comments on electrons in conductors are consistent with research results on student beliefs that current is the movement of electrons from one bound state of an atom to another. For more details on this research, click here.
Mark: Well, quantum mechanically, if that's the case, if an electron enters a resistor, if it's not bound, then it is bumping into things.
Fay: (note her hands moving around, showing an object bumping around in space).
Mark: But it's being pushed through by the electric field.
Mark: If it is bound, it's not going anywhere.
Fay: Exactly! But, since it came in, then it can't be bound, because all the bound ones are there.
Mark: Right, right. Whereas in the conductor it is entering bound states, but these are loosely bound states, that's a difference.
Fay: Yeah, or otherwise you can think of it as, you've got these - the dudes in the wire and they all have their electrons, right? all around them...
Fay: ...and you're just going to have an electron that goes whoosh de whoosh de whoosh (note her hand movement on the paper, this time presenting to the others the same hand motion she had done only for herself earlier).
Mark: So, in the resistor, we're looking at essentially unbound electron (nets?) going through physical obstacles. When I say physical, I mean mechanical obstacles, as opposed to quantum mechanical?
Jeff: Yech! (for the bad pun)
Mark: On the other hand, in the conductor, it's going from one bound state to another.
Jeff: yeah, it's kinda like the whole, ...
Mark: but loosely bound state!
Jeff: This is what I was thinking earlier...
Though many issues can be discussed based on this video clip, we emphasize four:
Return to Teacher's Guide.