Yurani Muratalla Experiment 14 Atomic Spectroscopy In this experiment spectroscopic methods were used to acquire knowledge regarding the light emitter by several atomic sources when heat in a flame through the use of a spectroscope From the data collected distinct conclusions about the relationship between atomic line spectra and atomic structure could be made In part one calibration for the spectroscope the main focus This was done by comparing the values projected by the mercury emission line spectrum from overhead lights into the spectroscope with the accepted values for each color of emission s wavelength This data was then graphed onto Excel and using the linear line on the graph calculations for wavelengths on other parts of the experiment were made possible According to the calibration graph created on Excel the equation relating the spectroscope scale reading and wavelength for this spectroscope in particular was y 0 0084x 1 1 A source of error from this part of the experiment could have been having a defected spectrometer causing it to report incorrect scale readings that would offset the equation Another systematic source or error could have been one due to the user incorrectly using the spectrometer perhaps by recording spectral lines incorrectly for that particular emission line spectrum In part two the emission spectrum of hydrogen atom was observed using the same spectroscope used in part one so that the previous calibration graph could be used in determining the wavelength emitted The lines observed were violet blue green and red Compared to the accepted wavelengths for the hydrogen atom emission lines the observed values followed the same trend increasing in the order of violet blue cyan green and red respectively as seen on the electromagnetic spectrum However two clear and minor problems were observed being that for violet the observed wavelength was 399 15 nm while for red the observed wavelength was 707 8 nm These values stray very little from the span of visible light spectrum 400 700nm that distinguishes whether these wavelengths and visible light can be seen by the human eye through the spectroscope According to this data the values are extremely close to the spectrum of visible light yet still weren t within the range of 400 700 nm However these colors were still seen through the spectroscope meaning that there must have been an error and these values should ve indeed have been within the range if they were visible The known electronic transitions for the hydrogen atom emission spectrum in the visible region called the Balmer series are 6 2 5 2 4 2 and 3 2 for violet blue cyan and red respectively The determined electronic transitions for violet blue cyan and red were 7 2 5 2 3 2 and 3 2 respectively These are somewhat reasonable values since they go from a higher energy level to a lower one implying that they are losing energy and therefore emit light Comparing both the determined electronic transitions blue and red were consistent unlike the one for violet and cyan which was calculated at one higher or lower energy level than it should ve been A possible error for this part of the experiment could have been in using an inaccurate calibration graph in the first place completely offsetting the values of the wavelengths recorded for each spectral line thus giving wavelength values that aren t even present in the visible spectrum Another error could have been in recording the scale reading making each value disproportionate with another when compared to accepted values In part three the emission spectra from alkali and alkaline earth metals were observed by putting metal salt solutions into flame When the calcium solution was put into the flame the flame exuberated in a bright red orange color When observed with the spectroscope while the flame was burning bright the emission spectra consisted of cyan yellow and red This process was repeated for each of the other metal solutions Sodium expressed a yellow orange color in the flame and the orange spectral line in the spectroscope Strontium expressed a bright scarlot red in the flame and the orange and red spectral lines in the spectroscope Barium exuded a bright lime green color in the flame and the orange and red spectral lines in the spectroscope Lithium exuded a bright magenta pink when put into the flame and the yellow and red spectral lines in the spectroscope Finally potassium exuberated a light lavender color in the flame and the yellow and violet spectral lines in the spectroscope When the spectral lines for each flame were observed it was made clear that the flame color was influenced by the combination of spectral lines present blue and yellow make green for example and their intensity expressed by wavelength Thus flame colors give a hint at which spectral lines are present what initial energy levels electrons are transitioning from and the intensity of the light according to wavelength
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