Trump University
Laboratory Report
Course #: PSYC123 Experiment #: 3
Diffraction Grating
Halima Abdulla
2435346457657
Date Performed: 09/02/2015
Date Submitted: 22/02/2015
Lab Period: Monday AM (L4)
Partner: Shiva Gomez
Station #: 45
TA: Gabrielle
Purpose:
The purpose of this experiment is to familiarize one with the use of grating spectrophotometer and using it to workout precise readings of the angles of the different fringes or lines observed through the scope in the spectrophotometer. This allows for the conversion of said angles to certain wavelengths and using this we can work out which gas was present in the source of light.
Theory:
When gas is subjected to high pressure and a high voltage is applied to it, some gas particles loose electrons and therefore become ionized. The released electrons also accelerates due to the high potential difference and knocks against other gas atoms. Upon collision the kinetic energy of the electrons cause more electrons to be released from subsequent atoms and therefore at one point there is an equilibrium established where the ions start to drop back to lower energy states from their high energy states and in the process the energy gained is released as photons or waves of light. These lights of different wavelengths emitted are characteristic of the energy levels available in the gas atoms, and each atom has distinct energy levels and therefore a certain gas will only emit lights of certain frequencies when excited. From these wavelengths, the certain element or gas can be worked out as each has its own unique spectrum.
Now the role of the grating spectrometer is to work out these certain wavelengths.
When light is emitted from a source, it travels in all kinds of different directions and not towards one direction only. When it passes through the diffraction grating, only certain directional waves of light can pass through and as...