Simple Photoelectric Effect Demo

This was submitted to the American Association of Physics Teachers Conference in Ann Arbor, MI.

Albert Einsteins Nobel Prize winning photoelectric effect has been demonstrated for many years quite effectively, yet now it can be done with simple household items. Past versions used specialized blacklights or carbon-arc lamps to show any effect. This version takes advantage of the currently popular germ sanitizer lights, which are much more affordable and portable. It also uses aluminum pop cans instead of zinc plates and Christmas tree tinsel instead of standard electroscopes.

For more information, please refer to...
http://tinyurl.com/26ut5dl

Category:

Education

Tags:

• photoelectric effect
• demo
• physics
• beehler

[kawaiixpro]

what is that white tube?



[PhysicsAstronomyUofU]

@kawaiixpro

There is an explanation of more information in the link provided in the video's description, yet the short answer is... The white rod is a PVC rod. When rubbed against the brown paper towel, the rod becomes net negatively charged.

[vamsivamsivamsi75]

if more than 1 light ray hit the electron then the electron gets more energy ,so why there will be use of threshold energy

[PhysicsAstronomyUofU]

@vamsivamsivamsi75 You are absolutely correct in that one electron may absorb the energy from multiple photons. Yet, the electron still needs a threshold energy in order to escape its nucleus. Multiple photon interactions could make this easier. The second photon must hit the electron quickly before the electron relaxes back to its original position, which happens quickly though. Relatively few electrons may escape this way with lower frequency light, but not the majority.

[realbadvirus]

This is the best home made science demonstration to date. Amazing.

[DrD0000M]

@kami645464 Actions speak louder than words.

[PhysicsAstronomyUofU]

@th3don147 I would say that the "free" (ejected) electrons bond the way they always do, but I have no idea if their "state" is any different. Regardless of whether the electrons are spin up or spin down should not affect their recombination with other atoms.

[PhysicsAstronomyUofU]

@th3don147 I am sorry but I do not exactly know what you mean by "state." Usually with photons, "state" refers to its polarization, yet with electrons it can mean different things.

[Zobaire90]

@PhysicsAstronomyUofU Thanks alot!

[PhysicsAstronomyUofU]

@Zobaire90

Great question! They have been given enough energy to escape the attraction of the atom's nucleus and travel outward and onward. They then run into something else (another atom) and interact with it, or they can enter a nearby electric field and be attracted one way or another first. Eventually they end up captured by another atom.

[Zobaire90]

@WimpyMcWeaksauce relax!

talk only on your behalf.....lol