Part A The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656 nm (red) and 486 nm (blue). Light from a hydrogen What is the distance between the first-order red and blue fringes? lamp illuminates a diffraction grating with 510 Express your answer to two significant figures and include the appropriate units. lines/mm , and the light is observed on a screen 1.6 m behind the grating. ? d = Value Units