The central star of a planetary nebula emits ultraviolet light with wavelength 104nm. this light passes through a diffraction grating with 5000 slits per mm. what is the first-order diffraction angle?

31.33 degrees

Explanation:

The diffraction angles when we have a slit divided into parts are obtained by  the following equation:

  (1)

Where:

is the width of the slit

 is the wavelength of the light

is an integer different from zero.

Now, the first-order diffraction angle is given when , hence equation (1) becomes:

  (2)

Now we have to find the value of :

  (3)

We know:

In addition we are told the diffraction grating has 5000 slits per mm, this means:

Substituting the known values in (3):

Finally:

>>>This is the first-order diffraction angle