The emission from C can be used for wavelength calibration of instruments in the ultraviolet. This is generally performed by electron-impact initiated decomposition of a precursor resulting in the prodiction of electronically excited C, which relaxes to the ground electronic state by emitting a photon at 193.09nm.

Suppose one wated to take another approach where C is heated until 5% of the atoms occupy the electronically excited state. Consedering only the lowest-energy ground state and the elctronically excited state, what temperature is required to achieve this excited-state population?