- Spectroscopy Object To Study Line Spectra For Various Elements Using A Spectrometer Apparatus Spectrometer Discharge 1 (148.93 KiB) Viewed 23 times
Spectroscopy Object: To study line spectra for various elements using a spectrometer Apparatus: Spectrometer, discharge tubes, diffraction grating, and power supply for discharge tubes Introduction If a high voltage is applied across the electrodes of a glass tube filled with a gas at low pressure, the tube emits light. The emission spectrum of one source is different from that of any other source and thus is a distinguishing characteristic of the source. A line spectrum is one in which distinct colors appear as separate bright lines in a spectroscope. In the late 1800's, Johann Balmer described the spectral lines of hydrogen using the following empirical equation: 1 -ER 2 where n=3,4,5,6,... (1) 22 n2 Ris called the Rydberg constant and it has the value 1.097 x 107m1. The wavelength of an observed spectral line can be experimentally determined by using a .. diffraction grating mounted on a spectrometer. A diffraction grating has many equally spaced slits. The distance between the slits is called the grating spacing d. When the light passes trough the grating it is diffracted and an interference pattern can be observed. Constructive interference occurs when d sin(O)=ma where m=0,1,2,... (2) where d is the spacing of the slits and m is the order number. The angle Ois measured as shown. Eyepiece Slit 6 Light Source 0 Order Diffraction Grating
4/30/2022 Do calculations for 2 lines 0 =15 (red J ② = 13 (blue-green) Use & 0 d sin o where d-2.546104 (1 Å= 1010m ) and x = 9,767/ 14 n where n=3 and a = 4 Compare the 2 sets of a values for each line (color) 2 of 2