Rotationsnivåer

Rotationsnivåer refer to the discrete energy levels that molecules can possess due to their rotational motion. According to quantum mechanics, the energy of a rotating body is quantized, meaning it can only exist in specific, allowed states. For a diatomic molecule, the rotational energy levels are often approximated by the rigid rotor model. In this model, the energy of a rotational level is determined by the rotational quantum number, J, and the molecule's moment of inertia, I. The energy E_J is proportional to J(J+1), where J can take integer values starting from 0. This means that as J increases, the rotational energy levels become more spaced out. Transitions between these rotational energy levels can occur through the absorption or emission of electromagnetic radiation, typically in the microwave region of the spectrum. The selection rule for rotational transitions in diatomic molecules is usually ΔJ = ±1, meaning a molecule can only transition to an adjacent rotational level. The study of rotational energy levels and their transitions is fundamental to understanding molecular spectroscopy and provides valuable information about molecular structure, such as bond lengths and masses. Deviations from the rigid rotor model, such as centrifugal distortion, can lead to more complex energy level patterns.