Nitrogen gas (N2) primarily interacts with photons in the ultraviolet (UV) region of the electromagnetic spectrum. The specific wavelengths that can excite nitrogen depend on the electronic transitions within the molecule.
The ground state of nitrogen, known as the electronic ground state, has a configuration called the singlet state (denoted as X). When photons with energies corresponding to the ultraviolet region of the spectrum interact with nitrogen gas, they can cause electronic transitions to excited states. The most common electronic transitions in nitrogen are:
Lyman-Birge-Hopfield (B-X) Band: This transition occurs at wavelengths around 120-200 nanometers (nm), corresponding to the deep ultraviolet region.
First Positive (C-B) Band: This transition occurs at wavelengths around 200-250 nm, also in the ultraviolet region.
Second Positive (B-A) Band: This transition occurs at wavelengths around 250-350 nm.
It's important to note that the specific wavelengths may vary slightly depending on factors such as temperature, pressure, and the presence of other gases. Additionally, nitrogen can also interact with photons in other energy ranges, but the UV range is the most relevant for its electronic transitions.