Achieve HW #7

[Joana Fang 1K]

a. As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over the cause of the sparking, with one stating that the microwaves "herd" electrons into "pointy" areas of the metal object, from which the electrons jump from one part of the object to another. The other friend says that the sparks are caused by the photoelectric effect. Prove or disprove the latter idea using basic physics.

Suppose the typical work function of the metal is roughly 5.030×10−19 J. Calculate the maximum wavelength in angstroms of the radiation that will eject electrons from the metal.

b. Considering that microwave ovens radiate at 2.45 GHz, how would you respond to the debate?

For Part B of this question, how would I know if something is caused by the photoelectric effect?

[Sunny Xiao 1A]

The photon energy (radiation) must be greater than the work function for the photoelectric effect to be the cause of the ejected electrons (sparks). Using the equation, Ephoton = work function + KEelectron, so KE must exist for the electron to be ejected --> Ephoton must be greater than work function.

[Alex_Lee_1K]

For this question you use
Ephoton = h(frequency)

Therefore it would be Ephoton = (6.626*10^-34Js)(2.45*10^9Hz)
Ephoton = 1.62*10^-24 J

Then you compare this to your work function that is given at the beginning of the question
If Ephoton < work function, then sparks cannot be seen

Hope this helped.