What type of atoms or molecules generate a UV spectrum?

Question

Quizplus · Accepted Answer

Molecules with π-electrons can absorb ultraviolet (UV) radiation due to their electronic transitions. These transitions are caused by the energy difference between the π-electron orbitals, which typically lies in the UV or visible region of the electromagnetic spectrum. Therefore, compounds containing π-electrons, such as conjugated systems in organic molecules, generate a UV spectrum.

What Type of Atoms or Molecules Generate a UV Spectrum