While calibrating a spectrometer, a technician observes that photons with a wavelength of 4.25μm are strongly absorbed by an unknown gaseous sample at 298 K.
(a) Calculate the energy, in joules per photon, that corresponds to radiation of wavelength 4.25μm. Show your work and include appropriate units.
(b) Using your result from part (a) and typical energy scales for molecular transitions, identify the most probable type of transition (rotational, vibrational, electronic, or nuclear spin) responsible for the observed absorption.
(c) Specify the portion of the electromagnetic spectrum to which the 4.25μm radiation belongs, and name one common laboratory instrument that uses this region to probe the type of transition you identified in part (b).