Atomic Time Line
Project
To help you piece together the story of what we know about the "atom", you will be creating a timeline
depicting the development of the scientific model of the atom. It has been through new discoveries by
philosophers and scientists in chemistry, as well as physics, that the model of the atom has expanded
and changed over time. Your assignment is to research the major contributors and significant
discoveries that have impacted the atomic model and, from this material, develop a timeline. You are
responsible for the information that you learn from your timeline.
Requirements:
Your timeline MUST:
1. Match each of the 12 scientists and/or philosophers located in the tables below
a. to key dates (LOOK UP and put in chronological order)
b. and also their contributions to the atomic model.
2. Include each of the following pictorial models of the atom, clearly labeling key characteristics of these
models (protons, neutrons, electrons, nucleus, etc…) to the Scientist who are identified by an astric
in the first table:
• indivisible, solid sphere model
• quantum mechanical model
• planetary model
• plum (raisin) pudding model
• nuclear model
3. Be chronological in its sequence, with the dates clearly shown (it need not be to scale), and at a
minimum include the information contained in the following table, but I would highly recommend
adding additional data.
4. Utilize through pictures and/or diagrams the significant contributions and experiments of those
scientists and atomic models examined in this project. For example, where an experiment or model
is listed as a contribution, one of the above items would be appropriate. A minimum of 3 pictures
and/or diagrams are required for the timeline. One of these pictures must include a hand drawn
portrait of one of the chemists. The other two should be a diagram explaining the experiment used
by the scientist.If these items are taken directly from a source(s), the source(s) must be cited using
APA or MLA format. You may want to use easybib.com or another website to keep track of sources.
5. Be neat and legible.
6. All Atomic Line Projects must be completed on Poster paper which I will provide.
Deadlines and Guidelines:
• Your timeline is due on ___________________________
• You will be working with a partner and each person is responsible for the material covered in the time
line!
• You do not have to follow the typical horizontal timeline format; you may be creative and use any
format you wish. We will spend some class time in the library and the computer lab to assist in your
research. One good option is a wagon wheel poster!
AP Chemistry R L Patton High
Required Information: (needs to be matched with
key contributions in next table and included timeline)
Key Scientists/Philosophers
Aristotle
*Niels Bohr
James Chadwick
*John Dalton
Louis deBroglie
Democritus of Adbera
Werner Heisenberg
Robert Millikan
Max Planck
*Ernest Rutherford
Erwin Schrödinger
*Joseph John Thomson
Key Dates (LOOK UP!!)
Contributions (Match to each of the above contributors)
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planetary model of atom
electrons travel in specified energy levels
spectrum lines produced when electrons move
atomos- indivisible
first to identify possibility of an atom
smallest piece of matter
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measured charge of an electron
oil drop experiment
completed with Thomson
“uncertainty principle”
impossible to determine the position and the momentum of
a particle at the same time
“cloud” model aka quantum mechanical model
electrons have properties of both waves and particles
group of waves named after this scientist
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showed mathematically that waves can be used to describe
electrons in atoms
determined probability location of electrons in atoms
Helpful Websites:
• http://profmokeur.ca/chemistry/history_of_the_atom.htm
http://www.nobeliefs.com/atom.htm
http://www.timetoast.com/timelines/history-of-the-atomic-model--36
education.jlab.org/jsat/powerpoint/atomos.ppt
http://en.wikipedia.org/wiki/Atomic_theory
http://www.easybib.com
AP Chemistry R L Patton High
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atoms can emit “quanta”
Einstein used this scientist’s work to study photons
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father of modern atomic theory
5 parts to theory
Elements are composed of the same atoms
Element’s atoms are identical in mass
Elements combine to form compounds
All compounds contain same atom ratio
discovered electron
described nature of cathode rays
plum pudding model of atom
four “elements”: earth, fire, air, water
believed in reasoning instead of scientific
experiments
dismissed Democritus’ atom idea as “worthless”
gold foil experiment
atom has small positive charged nucleus, remainder
is empty space
predicted existence of neutrons
helped with the development of the nuclear model
discovered neutron
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Grading Rubric for
Atomic Time Line Poster Project
Category
Name
Creativity
Expectation
1.____________________
2._____________________
Originality:
How much of the project is you?
Creativity:
How creative did you get with what you had?
(Color/shading/pictures/lay-out)
Project Design:
Did you stay within the required format?
Context
References
Group Evaluation
Extra Credit
Scientist:
Did you include all scientists and include discoveries and
experiments?
Atomic Models:
Should have labeled pictures of models including the dates.
Points
_____/10
_____/10
_____/10
_____/5
_____/30
_____/20
Work Cited Page:
Did you cite all references and site MLA or APA format?
_____/5
Peer Review:
How much input did you have in your project
_____/10
Scientist:
Scientist or philosophers who aided in the discovery of the atom
may be added to your timeline. All required information for the
original group of atomic scientist should be included. (MAX 5
scientist) Example of a few Wolfgang Pauli, Leucippus of Miletus,
Henri Becquerel, Francis Aston, and Amedeo Avogadro.
This Rubric should be glued to the back of your poster!!
AP Chemistry R L Patton High
_____/2 bonus
points per scientist /
philosopher. 10
point MAX