In a He-Ne gas laser an electrical discharge pumps helium atoms to a 20.61 eV excited state. This excited helium level is very close to a 20.66 eV level in neon, so that upon collision of a helium atom and a neon atom, the energy can be transferred from the He to the Ne atom. From this excited state, the neon atom then drops to a lower 18.70 eV state thereby emitting a photon. What is the wavelength of this photon?

a. The electron of a hydrogen atom is excited into a higher energy level from a lower energy level. A short time later the electron relaxes down to the no = 1 energy level, releasing a photon with a wavelength of 93.83 nm. Compute the quantum number of the energy level the electron relaxes from, nhi. Note: the Rydberg constant in units of wavenumbers is 109,625 cm-1 nhi =16 b. What would the wavenumber, wavelength and energy of the photon be if instead no = 1 and nhi = 4? V: 6.9121e14 x (cm-¹) λ: (nm) E: 45.8e-20 ✓ (1)

Q11

What is the energy in eV and wavelength in µm of a photon that, when absorbed by a hydrogen atom, could cause a transition from the n = 4 to the n = 6 energy level? (a) energy in eV?   (b) wavelength in µm?