States of Matter (week-long unit)

Interactive, scaffolded model

Overview and Learning Objectives

The module is focused on matter in its various states and the molecular properties of these states. Students are asked to reason using the kinetic molecular theory. The power of the kinetic molecular theory in understanding the states of matter lies in helping students understand the molecules themselves do not change during physical changes in substances such as melting; instead, the changes are reflected in different arrangements and motions of the molecules.

The module is focused on matter in its various states and the molecular properties of these states. Students will be asked to reason using the kinetic molecular theory. The power of the kinetic molecular theory in understanding the states of matter lies in helping students understand that molecules themselves do not change during physical changes in substances such as melting; instead, the changes reflect different arrangements and motions of the molecules.

Students will:

• run a model and analyze its reasonability and fidelity by comparing model outputs to a target phenomena;
• understand the behavior of a model by varying parameters, testing limits, and examining the interrelationships between variables;
• apply model-based reasoning by grappling with a variety of explanations and phenomena.

In understanding the models students will need to reason using the key scientific concepts from this unit. It is our belief that students will gain a greater understanding of the concepts they will be studying and a facility with creating and understanding their own models as a result of these activities.

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Assessment

1. Suppose you were the size of a molecule in a liquid, ethyl alcohol, for example, and could stand on the molecule in a glass. Someone takes that glass and puts it in the freezer. After a while, the alcohol freezes. How does what you see and feel change?
2. Draw a picture of a container that has 10 oxygen molecules in a gaseous state. Label the molecules A through J. Then draw a picture of the gas a "little while later." The second picture should show where you think the molecules A through J are at this time.
3. Draw a picture of a container that has 10 liquid water molecules. Label the molecules A through J. Then draw a picture of the water a

"little while later." The second picture should show where you think the molecules A through J are at this time.

1. Could there be a compressible liquid? Explain your answer using molecules/atoms in your answer.
2. Do you think a liquid is more like a gas or more like a solid? Why?

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Classroom Practice

http://www.concord.org/~barbara/workbench_web/states_of_matter/index.html

More from AAAS Benchmarks:

1. THE PHYSICAL SETTING G. FORCES OF NATURE: At the atomic level, electric forces between oppositely charged electrons and protons hold atoms and molecules together and thus are involved in all chemical reactions. On a larger scale, these forces hold solid and liquid materials together and act between objects when they are in contact, as in sticking or sliding friction.

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Central Concepts

Key Concept:

Kinetic molecular theory underlies an understanding of states of matter. The molecules themselves do not change during physical changes in substances such as melting; instead, the changes reflect different arrangements and motions of the molecules.

Additional Related Concepts

Physics/Chemistry

• States of Matter

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Textbook References

• Biology (Miller and Levine) Prentice Hall 5th Edition - Unit I: Chapter 3 - Introduction to Chemistry
• Biology: Exploring Life - Chapter 4: The Chemical Basis of Life
• BSCS Blue (8th Edition) - Chapter 1: The Chemistry of Life
• Cell Biology (Pollard and Earnshaw) Saunders 2002 - Chapter Two: Molecular Structures
• Web of Life - Chapter 2: Chemical Basis of Life

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Benchmarks and Standards

AAAS

• THE PHYSICAL SETTING: FORCES OF NATURE - There are two kinds of charges-positive and negative. (Full Text of Standard)
  
  

NSES

• Physical-Science: Matter Structure/Properties - 5 Solids, liquids, and gases differ in the distances and angles between molecules (Full Text of Standard)
  
  

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Activity Credits

Created by CC Project: Molecular Workbench using Molecular Workbench + Pedagogica

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Requirements

• Java 1.5+ - Java 1.5+ is available for Windows, Linux, and Mac OS X 10.4 and greater. If you are using Mac OS X 10.3, you can download MW Version 1.3 and explore within it instead.

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