Particulate Representation
& Reasoning in Chemistry
Sue Klemmer
Camden Hills Regional High School
Rockport, ME
sue_klemmer@fivetowns.net
http://klemmer-science.wikispaces.com
Resources:
Supporting Grade 5-8 Students in Constructing Explanations in Science: The Claim.
Evidence, Reasoning Framework for Talk and Writing by Katherine McNeil and Joseph
Krajcik (2012)
A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas
National Research Council (2010) (free download!)
How Students Learn: Science in the Classroom by the Committee on How People Learn:
A Targeted Report for Teachers, National Research Council (2005)
Models and Modeling in Science Education:Vol. IV, ed. by Gilbert & Treagust (2009)
The American Modeling Teachers Association at http://modelinginstruction.org
WHY BOTHER?

“If, in some cataclysm, all scientific knowledge were to be destroyed, and only
one sentence passed on to the next generation of creatures, what statement would
contain the most information in the fewest words? I believe it is the atomic
hypothesis …that all things are made of atoms.” - Richard Feynman Six Easy
Pieces 1994

“Students do not learn what we teach. If they did, we would not need to keep
grade books. We could, simply, record what we have taught.” - Dylan William
Embedded Formative Assessment pp. 47-48
MODELING, PARTICLES, & THE FRAMEWORK/NGSS
 “[Models are] explicit representations that are in some way analogous to the
phenomena they represent.” (Framework, p. 56)
o conceptual models: models accepted by the scientific community; often basis
of content standards
o mental models: individual understanding of how the world works; may or may
not be the same as conceptual models
 “At heart, modeling is about using tools to make sense of the world.” (pg. 56)
o students are expected to explain & predict phenomena using models
o students are expected to develop, test & refine models; this always starts with
mental models and works, over years, towards conceptual models
 “a set of skills and practices that allow a person to reflectively use a variety of
representations or visualizations, singly and together, to think about, communicate,
and act on chemical phenomena in terms of underlying … physical entities and
processes” (Kosma & Russell, 2005, p. 131).
put NGSS page on modeling progression here!
QUESTIONS FOR TEACHERS:
1. Do my students understand the representations I use?
2. Am I paying attention to the representations students use?
3. Am I helping students use representations to develop, test, and refine their
conceptual knowledge (models)?
MY CLASSROOM 2013-2014
• ask consistently for both macro/micro representations within existing demo
sequence of predict/observe/explain
• ask for macro/micro reps for labs
• have students use their reps to communicate, defend & refine their mental models
(concepts)
o Share your explanation with a neighbor. Critique both models: do they
explain what you saw? How are they similar/different? If you refine or
amend your diagram, do so in a different color.
o Apply model to explain a new demo or lab and refine.
• track changes (easier for labs!) over time for metacognition & formative
assessment
• be more deliberate and more transparent in my own use of representations in
lecture
• use next year’s classroom data to examine and better sequence summative
assessment representational demands
Name: _______________________________________
Date: __________________ Class: _______________
Journal Response
Syringe Demonstration
1. Predict: What will happen to pressure as the piston of the syringe filled with air is
pushed in? what will happen to P*V? Draw the syringes.
2. Observe: What did happen?
3. Predict: What will happen when the piston of the syringe full of air is pulled out?
what will happen to P*V?
4. Observe: What did happen?
5. Explain these observations in terms of the kinetic-molecular model of gases (aka
“the ping pong ”model). INCLUDE DRAWINGS (MODEL).
syringe
piston
6. Predict: Will there be any difference when the syringe is filled with carbon
dioxide instead of air? If so, what will the difference(s) be?
7. Observe: What did happen?
8. Is this consistent with Boyle’s Law? Explain why (not). INCLUDE A MODEL.
9. Predict: Will there be any difference when the syringe is filled with water instead
of air? If so, what will the difference(s) be?
10. Observe: What did happen?
11. Speculate on why water behaves differently than either gas. BE SPECIFIC, using a
MODEL. Can you put your ideas in the form of a testable hypothesis ?
SUMMATIVE EXAM IDEA:
Part 3: Observations, Models, & Theories
Ms. Heal and Mrs. Filip study melting ice cubes. Their volume data for cubes A-D are
given below. In all cases the ice cube’s mass did not change when it melted into liquid
water.
Sample
Label
Vol. Ice
(mL)
Vol. Water
(mL)
A
10.5
9.6
B
27.3
25.0
C
38.3
35.1
D
50.1
45.9
2. Summarize their observations about melting in 1-2 sentences.
3. Scientists often model matter as being made of tiny spheres, like miniature marbles.
Using this basic idea provide a possible explanation, with a “marble” diagram, for what
happens to ice when it melts.
“Exit Slip”
Particulate Reasoning Session
NEACT 2013 * Sue Klemmer
I teach: Check all that apply.
___ middle school
___ high school
___ college
___ chemistry
___ other sciences
____ mathematics
other:
I heard new things during this session:
strongly disagree
strongly agree
The results of this research were surprising to me:
strongly disagree
strongly agree
I am likely to reexamine my use of representations in my teaching.
strongly disagree
strongly agree
I am likely to change the way I have students use representations.
strongly disagree
strongly agree
.
Room for Optional Comments on Back!
Thank You!