Have you ever chewed on a wintergreen mint in front of a mirror inthe dark? If you have, you may have noticed some sparks of lightcoming out of your mouth as you chewed on the candy; and, withoutknowing it, you have experienced a physical phenomenon calledtriboluminescence. In this problem you will analyze some of the keyelements of triboluminescence in wintergreen candies.
When you break a sugar crystal with your teeth, energeticelectrons, released by the broken chemical bonds, collide withnitrogen molecules in the air. As a result of these collisions, theelectrons in the nitrogen molecules jump to a state of higherenergy; when they decay to their ground state, radiation isemitted.
Part A
Imagine that an electron in an excited state in a nitrogen moleculedecays to its ground state, emitting a photon with a frequency of8.88Ã1014 . What is the change in energy, , that the electronundergoes to decay to its ground state?
Express your answer in electron volts to three significantfigures.
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Part B
Considering that the highest intensity in the nitrogen spectrum is,in fact, recorded for radiation with a frequency of about 8.88Ã1014, will your eyes be able to detect this radiation?
yes
no
Correct
Light with a frequency of 8.88Ã1014 (and a wavelength of 338 ) liesin the ultraviolet region and our eyes cannot detect it.
Since the spectrum of nitrogen is mostly in the ultraviolet range,why is it that our eyes detect a bright light when we chew on asugar candy? The answer is in the wintergreen flavoring! Oil ofwintergreen, or methyl salicylate, is a fluorescent substance thatabsorbs high-frequency ultraviolet radiation and emits light atlower frequency.
Part C
Image that the radiation emitted by the nitrogen at a frequency of8.88Ã1014 is absorbed by an electron in a molecule of methylsalicylate. As a result, the electron in the wintergreen oilmolecule jumps to an excited state. Before returning to its groundstate, the electron drops to an intermediate energy level,releasing two-thirds of the energy previously absorbed and emittinga photon. What is the wavelength of the photon emitted by thewintergreen oil molecule?
Express your answer in nanometers to three significantfigures.
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