Question

If an emission line for magnesium appears at 285.2 nm in first order, where will it appear in second order? Where will it appear in third order? If you need to measure a first-order iron emission line at 570 nm, will the presence of the magnesium in the sample cause a problem at an instrument resolution of 1000? What can you do to solve the problem if it does exist? (Angle of diffraction isnt given)

Answer 1

The second order spectrum of magnesium will be at twice the first order wavelength.

The third order will have thrice the initial wavelength.

Using

So, 570.4 nm will cause a small problem. Even though the wavelengths are separate by a factor of 1 in resolution (which is theoretically enough), there will be a disturbance due to the fact that the peaks are not perfectly sharp.

So, to solve the problem, the slit width of the spectrometer can be reduced, since

Other factors that determine resolution can not be changed for an instrument.