[单选题]
In a ruby laser, an electron jump4oy f-lbwy e4o9 m8k7ns from a u 6gn-l1x/u auhigher energy level to a lower one. If the energy difference between the two levels is 1.8 eV, what is the wavelength of the emitteduux6 gu lan1/- photon?
A. $469 \; nm$
B. $649 \; nm$
C. $694 \; nm$
D. $964 \; nm$
Post time 2024-1-22 00:52:27