04.26.2020
Bohr Model of the Hydrogen Atom
Purpose: The purpose of this experiment was to demonstrate the spectrum of the Hydrogen
atom. In this experiment, two different models of Hydrogen atoms were compared which was
Thomson's Plum Pudding model and Bohr's model. On the last part of the lab, the Rydberg
constant was obtained from then slope of the graph based on the data from the simulation, and
it was compared to its known value.
A. Study the spectrum of the Hydrogen atom and compare it with the Thompson and Bohr models
Part I. Record an emission spectrum for atomic hydrogen
Include your snapshot below. Briefly describe it in terms of the regions of the electromagnetic
spectrum, estimated wavelengths and relative number of stacked colored balls. Theses correspond to
the photons emitted by the "ti" box.
Spectrometer:photonsemitted/nm
92UV380
500
600
700
780IR7500
Stop
Reset
1
ANSWER:
According to the snapshot above, the estimated wavelengths were in three regions. There is a
wavelength that was found with the value of 92 nm in the ultraviolet region. The wavelength for the
second region was between 390-440 nm, and it was near the ultraviolet region, however it is in visible
region. There is also another wavelength that was found about 680nm in infrared region. tior
comparing the relative number of stacked color balls, the number of balls in the range of 390-440nm is
almost half of the number of balls in other two regions.
Part II. Analyze two hydrogen atom models.
Thomson's Plum Pudding Model
Snapshot4:Plum Pudding
X
92 UV 380
500
600
700
780 IR7500
What is the atom like in this model?
The atom looks like a positive medium which contains negatively charged electrons What happens when photons interact with A) The photon bounces off the atom. the atom in this model? B) The electron changes position when struck by the Circle all correct answers. photon. C) A photon is absorbed and a different photon is emitted. D) The positive-charged proton "glue" interacts with the photon. E) All emitted photons have the same energy.
Is the resulting emission spectrum "right"? The resulting emission spectrum is not right because all the Why? emitted photons from the atom have the same wavelength which is opposite of the results from the observation on the previous step.
2
Bohr's Model
Snapshot2:Bohr
X
92 UV380
500
600
700
780 IR7500
What is the atom like in this model? Circle all correct answers.
A) There is a nucleus where the proton resides. B) There is an electron in motion in a circular orbit. C) There are several possible orbits the electron may follow. D) All of the above.
What happens when photons interact with When photons interact with the atom, the electron moves to the atom in this model? the orbitals with higher energy. This does not happen with Does the electron move? every single photon. In order for electron to move to the orbital with higher state of energy, the photon must carry enough energy.