Spectral Lines

1. Spectral Lines Caitlin Campbell

2. Spectrometer Instrument used to measure properties of light of the electromagnetic spectrum Enters through optical fiber, spectrometer refracts incoming light splitting into component wavelengths and records intensity with a detector Oceans Optics USB-4000 Spectrometer 350 nm to 1050 nm

3. Hydrogen Spectrum Balmer Series 486.1 nm 656.3 nm Transitions to n=2

4. Red Laser Helium Neon Laser 632.8 nm

5. Mercury lamp 435.835 nm (blue) 546.074 nm (green) pair at 576.959 nm and 579.065 nm (yellow-orange)

6. Blackbody Radiation Spectrum depends only on body’s temperature Shifts with increasing/decreasing temperature Have a maximum wavelength of emission related to their temperature Maximum about 655 nm so temperature about 4424 K Wein’s Displacement Law

7. Flashlight (Tungsten)

8. Flashlight (Tungsten)

9. Natural Sunlight

10. Natural Sunlight Sun’s temperature about 5800 K so using Wein’s Displacement Law maximum wavelength should be about 500 nm

11. Fraunhofer Lines Dark lines in solar spectrum are due to absorption by elements in the atmosphere 486.134 nm Hydrogen 516.733 nm Magnesium or 516.891 Iron 589.59/588.995 nm Potassium 759 nm Oxygen Line spectrum correspondsto the emission of photons from transitions from a higher state to a lower state of energy Atmosphere absorbs frequencies associated to the spectral lines of the elements it is formed of

12. Monitor Use RGB pixels Additive color model Eyes read as one color Used in electronic systems like computers and televisions

13. RGB Pixels Red 620-750 nm Green 495-570 nm Blue 450-495 nm

14. Blue Green

15. Uncertainties Noise from overhead light and other sources in room Age of lamps Spectrometer has 1 nm uncertainty approximately

16. Summary Elements’ spectral lines are like fingerprints

17. Questions? Thank you!