The energy of excited state molecules varies as a function of their electronic configuration due to the differences in energy levels between the ground state and the excited states. In general, the energy of a molecule in an excited state is higher than that in the ground state. This is because the electrons in the excited state have absorbed energy and moved to higher energy orbitals.The energy of an excited state molecule can be described by the following factors:1. Principle Quantum Number n : The energy of an electron in an orbital is primarily determined by the principle quantum number n . As n increases, the energy of the orbital also increases. When an electron is excited from a lower energy level to a higher energy level, the energy of the molecule increases.2. Angular Momentum Quantum Number l : The energy of an electron in an orbital is also influenced by the angular momentum quantum number l . For a given value of n, the energy of the orbital increases with increasing l. This is due to the increased electron density further from the nucleus, which results in a higher energy state.3. Spin-Orbit Coupling: In some cases, the interaction between the electron's spin and its orbital angular momentum can cause a splitting of energy levels, leading to different energy states for the same electronic configuration. This effect is more pronounced in heavier elements, where the spin-orbit coupling is stronger.4. Electron-Electron Repulsion: The energy of an excited state molecule is also affected by the repulsion between electrons in different orbitals. When an electron is excited to a higher energy level, it may experience increased repulsion from other electrons, which can further increase the energy of the excited state.5. Molecular Geometry and Environment: The energy of an excited state molecule can also be influenced by its molecular geometry and the surrounding environment. For example, the presence of nearby atoms or molecules can cause changes in the energy levels of the excited state molecule due to electrostatic interactions or other effects.In summary, the energy of excited state molecules varies as a function of their electronic configuration due to factors such as the principle quantum number, angular momentum quantum number, spin-orbit coupling, electron-electron repulsion, and molecular geometry/environment. These factors collectively determine the energy levels of the excited states and influence the overall energy of the molecule in its excited state.