[ethan]

Why are electronic, vibrational, and rotational spectra observed in different wavelength regions?

[ARGOS++]

Dear Ethan;

The Atoms/Molecules needs for each individual “Gymnastic” a different amount of Energy.

Remember that the Wavelength of Absorption is very strictly related to a corresponding amount of Energy. Also keep in mind that a rule of “Resonance” is also involved in a certain kind.

A Diagram that shows you the relation of all that you can find under the Question:
      “Why Einstein meets Beer-Lambert” (It’s just easier to remember!) on:

"Spectroscopy FAQ”

Good Luck!
                   ARGOS⁺⁺