Ruby lases at a wavelength of 555 nm. Acertain ruby crystal has 4.00 multiplied by 1019 Cr ions (which are the atomsthat lase). The lasing transition is between the first excitedstate and the ground state, and the output is a light pulse lasting2.20 μs. As the pulse begins,60.0% of the Cr ions in the first excited state and the rest are inthe ground state. What is the average power emitted during the pulse? (Hint: Don't just ignore the ground-state ions.)