There are many simple ways to illustrate ways in which solids can change to liquids. In this activity familiar materials, such as water, crayons, and food items, are used to illustrate the way in which matter changes form. These ideas can be done over a number of different lessons, depending upon the levels of the students. For students who are blind or visually impaired, they have not had the benefit of the incidental learning that takes place through informal observation. In other words, they will not have watched an ice cube melt in their glass and thus may not be aware that nothing was added or taken out of the glass, but that the ice cube changes form in warmer air temperatures.
Materials
ice cubes
small dish or bowl
crayons
warming tray or blow dryer (to melt crayons)
paper
candles
match (this experiment is only appropriate for students who understand the safety issues)
block of cheese
microwave
small blocks of chocolate or chocolate chips
ice cream
Procedure
Depending on the level of the students, this can be done in a series of lessons or in a single lesson.
Discuss with students how things change from one form to another. Ask if anyone knows what happens to an ice cube if you put it in a cup and leave it on the table or a counter.
Ask students to create a “hypothesis” or prediction about what will happen with the ice cubes.
Give each student an ice cube to place in a cup. Set the cups on a table and come back to check on them in an hour or so.
Have the students describe what happened.
Variations
Try melting crayons! Have the students predict what will happen if a blow dryer or warming tray is used with a crayon.
Similar experiments can be done with different types of food, such as ice cream, chocolate and cheese. Have students melt these and taste them before and after they are melted. Note that the taste stays the same, even though the texture changes.
For students who are aware of safety issues, try lighting a candle and note what happens to the wax next to the wick.