An atom in its ground state is excited when it absorbs a single photon of light. The atom then relaxes back to the ground state by emitting two photons, the first, a red photon at 700 nm, and the second, an infrared photon at 1750 nm. What is the wavelength of the absorbed photon? 1225 nm 1750 nm 700 nm 1950 nm 500 nm