Science
Strand IV
Use Scientific Knowledge from the Physical Sciences in Real-World Contexts

 

Science/Strand IV
Content Standard 2
All students will investigate, describe, and analyze ways in which matter changes; describe how living things and human technology change matter and transform energy; explain how visible changes in matter are related to atoms and molecules; and how changes in matter are related to changes in energy. (Changes in Matter)

 

Science/Strand IV/Content Standard 2
Middle School

 

Science/Strand IV/Content Standard 2/Middle School
Benchmark 1
Describe common physical changes in matter:

  • evaporation
  • condensation
  • thermal expansion
  • contraction

Benchmark Clarification

Students are often confused by the terms physical change and chemical change. It is important that they understand that mass remains constant in a physical change in closed systems. The amount of matter (stuff) remains the same; only the distance between the particles and the motion of the particles change.

Students will:

Š Describe the following physical changes in matter:

Key Concept / Real World Context / Instructional Example / Assessment Example / Resources

 

Science/Strand IV/Content Standard 2/Middle School/Benchmark 1
Key Concept
States of matter:

  • solid
  • liquid
  • gas

Processes that cause changes in states or thermal effect:

  • heating
  • cooling
  • boiling

Mass/weight remains constant during physical changes in closed systems

 

Science/Strand IV/Content Standard 2/Middle School/Benchmark 1
Real World Context
States of matter:

  • solid
  • liquid
  • gas

Changes in state:

  • water evaporating as clothes dry
  • condensation on cold window panes
  • disappearance of snow or dry ice without melting
  • expansion of bridges in hot weather
  • expansion and contraction of balloons with heating and cooling
  • solid air fresheners

 

Science/Strand IV/Content Standard 2/Middle School/Benchmark 1
Instructional Example

Benchmark Question: How does matter undergo physical change?

Focus Question: What physical changes take place when butane is heated and cooled?

Materials: 1 can butane lighter fluid, thirty locking sandwich bags, dry ice cut in small sections.

Each student will zip a small locking sandwich bag almost closed and leave an opening just large enough to insert the nozzle of a butane can. The teacher will squirt a small amount of butane (about one-quarter teaspoon) into the bag and quickly seal it. The body heat of the students’ hands and fingers will cause the butane to boil and become a gas that inflates the bag. Students will discuss why the bag inflates (the volume of the gas increases, because the molecules move farther apart). Students may rub their bags over a small block of dry ice to reduce the heat energy in the bag. Students will discuss why the bag deflates (the volume of the gas decreases, because the molecules move closer together).

Students will draw a picture of the molecular motion for each change of state the butane undergoes.

This experiment can be repeated as often as desired and the changes of evaporation and condensation discussed. Sublimation of the dry ice can also be discussed.

Caution:

  • Students should be aware of the dangers of butane gas (do not inhale, flammable).
  • Students should dispose of butane gas properly.
  • Room should be well ventilated during activity involving butane gas.
  • Do not reuse bag for other activities.
  • Do not handle dry ice with bare hands.

Note: Due to the porous property of the locking sandwich bags, bags cannot be prepared in advance.

Constructing: (SCI.I.1.MS.1), (SCI.I.1.MS.6).

Reflecting: (SCI.II.1.MS.5).

 

Science/Strand IV/Content Standard 2/Middle School/Benchmark 1
Assessment Example

The teacher will present the following scenario:

Angelo wanted to make some spaghetti. He put a pot of water to heat on the stove and left the kitchen for several minutes. When he returned he observed the following: The water was bubbling, the water gave off heat, steam was rising from the pot, water droplets were on the hood above the stove, and the water level was lower in the pan. He was puzzled about the source of the water droplets on the hood above the stove.

Each student will write a letter to Angelo and explain where the water on the hood came from. Each letter should include a diagram with labels.

Note: The teacher may want to demonstrate this activity before students write.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Accuracy of explanation-evaporation

Explains the process of evaporation with many misconceptions/ contradictions.

Explains the process of evaporation with a few misconceptions/ contradictions.

Explains the process of evaporation with one misconception/ contradiction

Explains the process of evaporation with no misconceptions/ contradictions and provides a labeled diagram.

Accuracy of explanation-condensation

Explains the process of condensation with many misconceptions/ contradictions.

Explains the process of condensation with a few misconceptions/ contradictions.

Explains the process of condensation with one misconception/ contradiction.

Explains the process of condensation with no misconceptions/ contradictions and provides a labeled diagram.

 

Science/Strand IV/Content Standard 2/Middle School/Benchmark 1
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.IV.2.MS.1.html

Steamed Up. NEW DIRECTIONS UNIT.
http://www.BCMSC.k12.mi.us/

Water, Precious Water. AIMS.
http://wwws.aimsedu.org/aimscatalog/default.tpl

Gregg Zulauf–Math and Science Center, Muskegon, Michigan.