Quantum MechanicsCatherine Lozier02/19/2013Chem 1310 Section C02TA Ryan BucherLab Partners:Chelsey Arnold Sunya MorinTran GHonor Pledge: I did not copy this work from any others student(s), current students in lab or old lab reports ________________________________________________SignatureDATA AND OBSERVATIONSPart Aλ HeNe laser: 632.8 nmOrder, n L*(cm) W (cm) Hypotenuse (m) D-Calculated (m)1 97 13 0.9787 4.778E-62 97 26.5 1.0055 4.858E-63 97 41 1.0531 5.002E-6Average distance between diffraction grooves: 4.879E-6 mPart BContinuous White Light EmissionColor λ Range (nm)Violet 400-440Blue 440-480Green 480-550Yellow 550-570Orange 570-600Red 600-670H Atom Emission LinesH Lines λtrial 1 (nm) ninitialViolet 410 6Violet-blue 430 5Blue-green 475 4Red 655 3Balmer Series ΔE, 1/n21/n2initialΔE0.0278 -4.8322 * 10-190.0400 -4.6074 * 10-190.0625 -4.1709 * 10-190.1111 -3.0247 * 10-190.03 0.04 0.06 0.11-5.000E+00-4.500E+00-4.000E+00-3.500E+00-3.000E+00-2.500E+00f(x) = 0.59x − 5.62R² = 0.88ΔEnergy v. n2initial-1n2initial-1ΔEnergy (10-19 J)Atomic Emission Spectra for HeColor λtrial 1 (nm)Violet-blue 445Blue 470Green-blue 490Green 500Orange 590Red 655Red 700Part CMetal Ion Colors Observed RemarksLiNO3Red Took a long time for the color to appearBa(NO3)2Yellow-greenKNO3Pale pinkishSr(NO3)2Red Took a long time for the color to appearCa(NO3)2Red-orangeCu(NO3)2Blue-greenCALCULATIONSΔE = hc/λΔEviolet-blue = (6.626*10-34 m2kg/s) * (2.99*10-8 m/s) / (430*10-9 m)ΔEviolet-blue = -4.6074 * 10-19JEionization = 2.18*10-18J * Z2 * 1/n2initialEionization = 2.18*10-18J * 1 * ¼Eionization = 5.45*10-18 JDISCUSSIONPart AThe objective of Part A is to demonstrate the wave nature of light and apply the diffraction equation to a setof maxima data to determine the spacing of the grooves of the diffraction grating used. Based on the maxima distance data collected, the average groove distance was calculated to be 4.879E-6 m. However, the groove distance calculated for individual maxima varied greatly. The highest value calculated was 5.002E-6 m, and the lowest was 4.778E-6. It can be noted that the calculated distance between the grooves increased at a regular rate corresponding with the n value. This indicates that there was some systematic offset in the measurements. This is likely due to Observed Atomic Emission Spectra for He (λ nm)Observed Atomic Emission Spectra for Hg (λ nm)Atomic Emission Spectra for HgColor λtrial 1 (nm)Violet 405Violet-blue 430Green 545Yellow-orange 575human error in the measurements, as the distance measurements were made using a meter stick held against a whiteboard. Also, the markings for the maxima points were eyeballed, and made using a dry erase marker. The combination of all these sources of human error could have contributed to the inconsistent values calculated for the diffraction grating groove spacing.Part BThe objective of Part B was to use a spectrometer to observe and compare the emission spectra of several elements. The wavelength ranges observed for the visible light spectrum were close to the expected width, although they were offset by approximately 20 nm for every range. This may be due to an improperly calibrated spectrometer,as the instruments could be calibrated by the user. Any offset would be considered a source of strategic error. For hydrogen, the observed atomic emission spectrum was very close to the expected atomic emission spectrum. The greatest difference between the observed and expected wavelengths was 10 nm, as the observed wavelength of the ninitial = 4 line was 475 nm, and the expected value was 486 nm. This difference was likely due to human error, as the spectrometer was not especially well marked, and the location of the spectral line had to be estimated. The plot created from the n-2initial and ΔE data did not fit the linear model very well, as the R2 value for the linear regression equation was 0.8842. Although this is roughly linear, the data was expected to adhere better to a linear equation, according to the Rydberg formula.For mercury, the observed emission spectrum was extremely close to the expected values. The greatest difference between the observed and expected values was approximately 6 nm for the violet-blue line. As for the helium emission spectrum, not all expected lines were observed. However, in each case where a line was omitted, there were two expected lines within 10 nm of each other, and the observed line was between the two. This was the case for the line observed at 445 nm, which is between the expected lines at 444 nm and 447 nm. A line was also observed at 500 nm, which is very close to the expected lines at 501 nm and 504 nm. These errors were likely due tohuman error, as the human error has limited resolution, and the lines had to be interpreted by the viewer. Overall, theobserved atomic emission spectra were very close to the expected values.Part CPart C was intended to demonstrate that different metal ions emit different wavelengths when thermally excited. Thecolors observed were consistent with the expected colors emitted by the metal ion. The KNO3 flame appeared pinkerthan the expected violet color; however, the flame was very pale, and the color was open to interpretation. Any difference in the flame colors would likely be due to Bunsen burner contamination. Also, balsa wood sticks were used instead of metal loops, and some sticks burned. This might have also affected the color observed. In general though, the observed flames corresponded to the expected flames for each metal ion.DISCUSSION QUESTIONS1. Individual bands were observed because as individual electrons move to lower energy levels, discrete wavelengths of light are emitted that correspond to the initial energy level of the electron. Because the electrons of hydrogen move from energy levels n = 6, 5, 4, and 3, only four distinct wavelengths are emitted.2. The linear relationship between n-2initial and ΔEnergy indicates that the data followed the Rydberg formula, 1/λ = R∞(1/n12 – 1/n22). Energy is equal to hc/λ, which is proportional to 1/λ, and satisfies the left side of theequation.3. The absolute value of the y intercept is the ionization energy needed to ionize an electron in the n=2 orbital.REFERENCES Lab ManualChemistry for Engineering Students, Second Edition. Lawrence S. Brown, Thomas A.