Study Guide 6, Self Test 2 STUDY GUIDE 6, SELF TEST 2

© Physics Department, University of Guelph

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1. Typical visible, infrared and microwave wavelengths are, respectively, 500 nm, 5.0 mm, 5.0 mm. Calculate the ratio Er/Ee, Ev/Ee, and Er/Ev. (r = rotation, v = vibration, e = electronic)

2. A molecule absorbs a photon of wavelengthla. The molecule both fluoresces with wavelength lf and phosphoresces with wavelength lp. Arrange these three wavelengths in order of increasing wavelength.

3. A sample is irradiated with a burst of light in a parallel beam of which contains 1.0 x 1018 photons.  The wavelength of the photons is 500 nm and the absorbance of the example is 0.680.

a) How many photons are in the transmitted flash and what is their wavelength?

b) If the number of photons is conserved (quantum efficiency = 1),  then how many photons are fluoresced?

c) The wavelength of the fluoresced photons is 700 nm.  How much heat (J) is deposited in the sample?