Download Atomic Models Handout

Developing the Modern Atomic Model
Our understanding of the atom has changed drastically over time. Most significantly, empirical
evidence from the past two centuries has helped to develop our latest model of the atom – the
quantum mechanical model.
Fill out the graphic organizer below using your textbook and internet resources to summarize how past
atomic theories have evolved into modern atomic theories.
Early Greek Understandings (400 B.C.)
Aristotle – 4 elements
Democritus
-
All matter is made up of atoms and void
(empty space)
Atoms are indivisible
Limitations:
- Based on pure reason, not empirical evidence (experimentation)
- There are 100+ elements (not 4)
- Atoms are divisible
Flash forward 2000 years…
Scientist: John Dalton
Diagram:
Name of Model:
Date:
Empirical Evidence:
Limitations:
Theoretical Explanation:
Scientist: J. J. Thomson
Diagram:
Name of Model:
Date:
Empirical Evidence:
Theoretical Explanation:
Limitations:
Scientist: Ernest Rutherford
Diagram:
Name of Model:
Date:
Empirical Evidence:
Limitations:
Theoretical Explanation:
Scientist: Niels Bohr
Diagram:
Name of Model:
Date:
Empirical Evidence:
Theoretical Explanation:
Limitations:
Check Your Understanding:
1. What evidence invalidated Dalton’s
atomic model?
2. If Thomson’s model of the atom had
been valid, what would Rutherford have
observed in the gold foil experiment?
3. Rutherford’s observations could not
account for all the mass in the nucleus.
Describe the discovery (and scientist)
that provided an explanation.
4. A ladder and a ramp are one analogy
for quantized vs. continuous energy.
Explain. OR create your own analogy
and explain.
Scientist: Various
Diagram:
Name of Model: Quantum Atomic Model
Date:
Empirical Evidence:
Theoretical Explanation:
Limitations:
List names of scientists involved in the Quantum Atomic Model and briefly list their
contribution:
Scientist
Year
Contribution