Moving directly at one another, two hydrogen-like atoms collide head-on with each other. After this collision occurs, both of the atoms will cease their motion entirely. Each atom will then emit a photon with a wavelength of 102.6 nm which corresponds to a 3 -> 1 transition. Determine what the initial speed of each atom was before they collided with each other?

• A. 43600 m/s
• B. 48200 m/s
• C. 51300 m/s
• D. 53700 m/s

Answer: (B)