Final answer:
To find the wavelength of the light, divide 1 by the number of lines per millimeter on the diffraction grating. In this case, the wavelength is approximately 1.25 x 10^-3 mm.
Step-by-step explanation:
To find the wavelength of the light, we can use the equation:
wavelength = 1 / (lines/mm)
Given that the diffraction grating has 800 lines/mm, we can substitute the value into the equation:
wavelength = 1 / 800 mm
Simplifying the equation, we find that the wavelength of the light is approximately 1.25 x 10^-3 mm.