Part 1 - Varying Wavelength Procedure: 1. Choose a slit distance and screen distance, these should remain constant for the rest of this part of the investigation. Change wavelength within the wavelength range and count the number of bright bands. (2 pts) d= (mm) L = (m) Wavelength Range Wavelength ()) chosen # of Bright bands observed 380-440 440-500 500-560 560-620 620-680 680-760