Lawrence D.
Margerum and Maren Gulsrud, University of San Francisco
In this
assignment you will:
- Explore a
computer simulation of the absorption and emission process in the Bohr model of
a hydrogen atom.
- Observe what
happens to the electron following the absorption of different photon energies
and record all observed emission wavelengths.
- Write a
short essay describing the absorption and emission process in the H-atom using
your recorded results.
You will use
the OWL Tutor/Simulation by Bill Vining, John Kotz and Patrick Harman.
Unit 7-4a: Simulation:
Atomic Absorption and Emission. This is the simulation for the Bohr atom
The simulation
allows you to shoot a photon at a H-atom and observe the results. There may be
several different outcomes to each photon-absorbing event, so be sure to repeat
each experiment several times. Remember that the H-atom has only one electron.
The energy levels shown here only apply to the H-atom (multiple electron atoms
are more complex). The goal is to help you understand the concepts of atomic absorption and emission.
Source
Material Resources:
HTML Tutor - This website has information about
how to put in HTML tags so that your essay looks correct when it is displayed. For this
essay, pay close attention to superscripts and paragraph formatting.
URL: http://www.cwu.edu/~verheys/howto.html
OWL Login
Page - Use your name and password to login.
Proceed to Unit 7-4a and load the simulation of absorption and emission.
1. Go to
OWL Unit 7-4a Atomic Absorption and Emission
2. Continue
with the questions at the bottom of this page. Many of these questions will
help you with your essay. Pay close attention to the energy levels in the
H-atom and the wavelength(s) of emitted photons. Answer the questions in the
simulation. For the last question (#9), make a table with two columns:
Wavelength
Absorbed
Wavelength(s) Emitted.
a. Record
the results of your exploration in nm. Keep repeating the simulation at the
same incoming wavelength to see all possible photon emissions. Try all three
incoming wavelengths.
3. Return
to this site and write your essay describing the absorption and emission
process in the H-atom using your recorded data. It should begin with a topic
sentence (an introduction to what you are about to describe). The essay should
be brief and should
clearly answer all of the Guiding Questions
4. Use
the correct HTML
formatting in your essay for any superscripts and paragraphs as explained in
the HTML tutor. Be
sure to do a spell-check and a grammar-check (in MS-Word under Tools menu, Spelling and Grammar).
In studying
the resources and writing your text, consider the issues raised by the
following questions:
1) How would
you describe the process of emission after viewing the simulation? What
specific events must occur in order to see emission(s)?
2) What is the
effect of decreasing the wavelength of incoming photons on the ability of the
H-atom electron to reach higher energy excited states?
3) How many emission
events are possible from the highest energy excited state?
4) Can you
make the connection between the line spectrum of the hydrogen atom in the
visible region and the emission events in the simulation?
a) How many
emission events fall in the visible region of the EM spectrum?
b) Be sure to
identify the color of the lowest energy emission event in the visible region.
Write your
essay for another student in your class who is having trouble understanding the
simulation.
Write a
description of the absorption and emission process for the Hydrogen atom using
the data you recorded from the simulation.
- Begin your
essay with a brief topic sentence that introduces the purpose or goal of the
simulation experiment.
- Make sure
that you adequately describe the important events from the Atomic Absorption
and Emission
simulation. Use examples. (i.e., you may want to describe what happens to the n
value when a given photon is absorbed or emitted).
- Your essay
should answer all the issues raised in the Guiding Questions, but remember that
you are writing an integrated essay, not just a list of answers.
- Be sure to
write a concluding or summary sentence at the end of your essay (i.e. What
should your fellow student learn from this simulation?).
In your essay,
use the guiding questions to decide what source material is relevant and
important. Be brief and concise in your explanations (approximately one to two
sentences for each guiding question).
Your essay
will be graded on a 10 point scale by three of your fellow classmates
(anonymously). A maximum of three points will be awarded for style (evidence of
a topic sentence and no spelling or large grammar mistakes). A maximum of 7
points will be awarded for content (the answers to guiding questions are
correct). Remember that plagiarism (copying word for word) is not acceptable
from source material or from other students. The instructor reviews all essays.
Copyright )2003 by Lawrence D.
Margerum and Maren Gulsrud.