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Photons of light with an energy of 656 nm are being directed through a chamber o

ID: 499193 • Letter: P

Question

Photons of light with an energy of 656 nm are being directed through a chamber of hydrogen gas atoms. The gas atoms began in their ground state (ni=1).

What happens?

A.Very few photons will be absorbed since there is not quite enough energy to have all of the electrons go from ni=1 to nf=2.

B.Photons with an energy of 656 nm are quite energetic. These photons will produce many different electronic energy transitions, e.g. ni=1 to nf=2 and ni=1 to nf=3 and ni=1 to nf=4, etc.).

C.These photons of light pass through the chamber without affecting the gas.

D.All of the photons will be absorbed since they have a specific energy and electronic transitions are quantized.

A.Very few photons will be absorbed since there is not quite enough energy to have all of the electrons go from ni=1 to nf=2.

B.Photons with an energy of 656 nm are quite energetic. These photons will produce many different electronic energy transitions, e.g. ni=1 to nf=2 and ni=1 to nf=3 and ni=1 to nf=4, etc.).

C.These photons of light pass through the chamber without affecting the gas.

D.All of the photons will be absorbed since they have a specific energy and electronic transitions are quantized.

Explanation / Answer

From Rydburg's Equation , 1/ = R[(1/ni2) – (1/nf2)]
   Where R = Rydburg's constant = 10.96 x106 m-1
               = wavelength = ?
               ni = 1
               nf = ?

   = wave length = 656 nm = 656x10-9 m

Plug the values we get

[(1/ni2) – (1/nf2)] = 1/(R) = 0.139

(1/nf2) = (1/12 )-0.139 = 0.861

nf2 = 1.161

nf = 1.07

A.Very few photons will be absorbed since there is not quite enough energy to have all of the electrons go from ni=1 to nf=2.