Spectroscopy Lab Report

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5 Spectroscopy Lab Report Rowan Paulsen Lab Section 099 13 October 2022

7 2.18 E -18J, c = 3 E 8m/s, and h = 6.626 E -34. It is important to note that n f will always equal 2 because we are dealing with visible light which is only emitted at n=2. For the other sources, we will calculate energy of the photon and frequency. Photon energy will be found using the equation listed above, and frequency will be found using v=c/ λ. Calculations and Discussion 1. Line Spectrum a. Hydrogen Color Wavelength (nm) Energy (photon) n (initial) Red 650nm 3.06E-19J n = 3 Orange 590nm 3.37E-19J n = 3 According to Figure 2.12 of Chemistry : Structure and Properties, Second Edition by Nivaldo J. Tro, the energy level corresponding to the red wavelength is correct. An electron that was excited to n=3, then relaxed to n=2 would emit a photon of red light with a wavelength of 657nm. This is very close to our recorded value of 650nm. However, my partner and I did not record any blue-violet or blue-green light as indicated by the figure. b. Florescent Light Color Wavelength (nm) Frequency (Hz) Energy (photon) Red 610nm 4.92E14Hz 3.26E-19J Green 540nm 5.56E14Hz 3.68E-19J Blue 440nm 6.82E14Hz 4.52E-19J

8 c. Neon Color Wavelength (nm) Frequency (Hz) Energy (photon) Red 640nm 4.69E14Hz 3.11E-19J Orange 600nm 5E14Hz 3.31E-19J d. Mercury Color Wavelength (nm) Frequency (Hz) Energy (photon) Green 550nm 5.45E14Hz 3.61E-19J Blue 440nm 6.81E14Hz 4.52E-19J e. Helium Color Wavelength (nm) Frequency (Hz) Energy (photon) Red 660nm 4.54E14Hz 3.01E-19J Yellow - Orange 580nm 5.17E14Hz 3.43E-19J Green 500nm 6E14 3.98E-19J Blue 450nm 6.67E14Hz 4.42E-19J 2. Continuous Spectrum a. Incandescent Bulb Color Wavelength (nm) Frequency (Hz) Energy (photon) Blue 450nm 6.67E14Hz 4.42E-19J Orange 590nm 5.08E14Hz 3.37E-19J

10 Example of frequency calculation: Conclusion The purpose of this experiment was to learn how to record the wavelengths of a given light source and use those values to determine frequency, energy level, and the energy of the photon emitted. My findings were somewhat supported by the expected, theoretical results. The reason some of my data differed from previous scientific evidence is because of inaccurate measurements. When aiming the spectrometer at a light source, we may have been slightly off and therefore unable to record certain photons. We also may have had a slightly uncalibrated spectrometer. However, the wavelengths we were able to record correspond to the expected results. Ultimately, during this experiment I learned how to use a spectrometer and how it works.

11 I also learned why the Bohr model only works for hydrogen and that wavelength and frequency are inversely proportional.