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i am reviewing for a physics exam tomorrow. they posted practice problems and with answers but dont show you how to get the answers. i got most the problems but there are a few im not sure so figured i would come here and see if you guys can explain it to me.

the problem is as follows

Problem 3: A certain metal is kept at a very low temperature. It is observed that when

photons with energies between 0.2 and 0.9 eV strike the material, only photons of 0.3 eV,

0.4 eV and 0.7 eV are absorbed. If the metal is heated to the point that 0.7 eV photons are

emitted, what photon energies would you expect to observe?

A. 0.3 and 0.7 eV

B. 0.1, 0.3, 0.4, and 0.7 eV (correct answer)

C. 0.3, 0.4 and 0.9 eV

D. 0.2, 0.4, and 0.7 eV

E. 0.7 and 0.9 eV

i dont even know where to start or how they got this answer. second line syas something about 0.2 - 0.9 eV and the answer has a 0.1??

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# Homework Help: Help Reviewing for exam

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