Home

Catalog

Contact Us

What's New

Site Map

Links

Evaporation and Condensation MatchCard

Explore the states of matter with the Freezing, Melting, Evaporation and Condensation Matchcard.

science-matchcard

Freezing, Melting, Evaporation and Condensation MatchCard

Objective: Explain how molecules change when a substance freezes, melts, evaporates, and condenses.

This cool science experiment will demonstrate some of the changes a substances undergoes as it changes from solid to liquid to gas.

Freezing

With the first part of this experiment, the student will examine how a liquid changes as it freezes into a solid. A re-sealable sandwich bag can be used as the water changes to the other states and back again.

Measure 1/2 cup of water into the bag.
Remove most of the air from the bag. The bag should be flat except for the water.
Mark on the side of the bag the top of the water.
Put the bag in the freezer. Wait until it freezes completely.
Examine the bag. Note how the ice takes up more of the bag than the water.

Explain that the molecules got closer together, until they joined in a lattice-shaped form.
Illustrate this by holding on to each other with outstretched arms and locked elbows. You are further away.

The liquid state can be illustrated by pulling your arms in with your elbows bent. You can touch each other arms with your elbows. You are allowed to move around, but keep touching arms. You closer together, but moving more. You are also not as tightly connected. .

Melting

Melting is one of the easiest transitions of the states of matter to understand.

Let the bag sit out at room temperature.
Let younger students predict what will happen.
When the water has melted, notice the water level compared to the mark on the bag.
Remeasure it to see that it is 1/2 cup still.

Use the Evaporation and Condensation MatchCard to illustrate the temperature changes that occur as substances move from the solid to liquid to gaseous state.

Evaporating

If younger student are not familiar with the process of evaporation, do this common experiment before returning to the sandwich bag experiment .

Put 1/4 cup of water in a pan.
Turn the stove on to high. .
Watch the liquid boil and evaporate.
Point out the steam.

Now let's return to our sandwich bag. This can be done with a microwave. As an alterative, the bag can be placed in a full pot of boiling water.

Be careful to avoid skin burns with this experiment.
Use the microwave or stove top to boil the water in the bag. You do not have to boil all of it.
Note that there is less water, but the sandwich bag is bulging out. What makes it bulge (the water vapor)

Explain that as molecules heat up, they move faster. They get further apart and have no bond with each other.

Illustrate this with a group of blind folded people playing group tag in a room. You are not connected, you are moving quickly, you bump into each other, and you take up more space.

Condensation

Condensation occurs as a substance in the vapor state (gas) is cooled and returned to a liquid state. .

Allow the sandwich bag to cool slightly, so it is warm but not hot.
Put ice cubes or a cold jar from the refridgerator next to the bag so it is touching it.
Watch the water drops form along the side of the bag that is being cooled. .

This principle can also be demonstrated with the pan of boiling water. Place a spoon (particularly a cool spoon) in the steam. Note the liquid on the spoon as the water vapor condenses.

Point out the illustrations on the Evaporation and Condensation MatchCard to show the movement of molecules as the states of matter change.

The Hunt

Brainstorm situations where they have seen substances freeze, melt, evaporate, and condense.
Make a list.
Have a six week hunt. See who can point out situations when a substance is moving from one state to another.
Condensation is the hardest to recognize. Here are a few situations you may wish to point out if the students don't find them:
- condensation on the outside of an ice cold glass on a hot day
- condensation on the inside of a windshield on a cold day
- fog on your glasses when you go into hot air or open the stove
- fog
- dew on the grass

Additional idea: Illustrate or photograph some of these scenarios.

Using the Evaporation and Condensation Matchcard

This is the 6th Matchcard of the Light and Energy Unit Study. You can download the Evaporation and Condensation MatchCard here.

The student matches the characteristics of freezing, melting, evaporating, condensing with the illustration on the MatchCard.

The second page is the Instructor's Guide with the correct answers.

The third page has the Information Pieces. Student's cut them apart and place them in the correct place on their copy of the Matchcard (first page.)

For more information on how to use the Matchcards, see the MatchCard Science Instructor's Guide.

MatchCard Science

The activities and illustration above are from MatchCard Science, a homeschool science unit study. For the complete Light and Energy Unit Study follow this link. This unit study provides:

hands-on demonstrations
MatchCard reviews to master the material
suggestions for science projects to complete
instructions on a complete unit study curriculum

Currently this curriculum is under-going revision. We are providing free access to the unit study, with the desire that you will provide feedback as you are field testing the materials.

Science Notebook

If you are just using this single project, and are not in need of a full unit study, you might want your student to complete a science notebook entry for this project.

Return from the Evaporation and Condensation MatchCard to the MatchCard Science Main Page.