When salt is sprinkled on a flame, yellow light consisting of two closely space wavelengths 11=588.997 nm and A2=589.594 nm are produced (they were observed by Fraunhofer in the Sun's spectrum). a) If this light falls on a diffraction grating with 300 lines/mm (pay attention to the units!), what is the angle between the 2nd order spectra of these two wavelengths? b) How many lines N of this grating must be illuminated for these lines to just be resolved?

When salt is sprinkled on a flame, yellow light consisting of two closely space wavelengths 11=588.997 nm and A2=589.594 nm are produced (they were observed by Fraunhofer in the Sun's spectrum). a) If this light falls on a diffraction grating with 300 lines/mm (pay attention to the units!), what is the angle between the 2nd order spectra of these two wavelengths? b) How many lines N of this grating must be illuminated for these lines to just be resolved?