[单选题]
In a ruby laser, an electron jumps f9 o6u albuh-n6rom a higherhqi7d yzfepwu p2*g2x/+fg +/ energy level to a lower one. If the energy difference between the two levels is 1.8 eV, what is the wavelength of the efq yfpp7g* d 2wixg+//2hz+u emitted photon?
A. $469 \; nm$
B. $649 \; nm$
C. $694 \; nm$
D. $964 \; nm$
Post time 2024-1-22 00:52:27