Solids, liquids and gas, often called states of matter, appear in most second grade science curricula. Go beyond showing your students pictures of these states of matter and lecturing them about the differences, and incorporate a variety of entertaining and participatory activities into your science class. Not only will your second-graders have more fun, but they're also more likely to remember what they've learned.
Describe the Matter
Start a guessing game by teaching your students what a solid, liquid and gas are. Then hold up a variety of objects, such as a bottle of water or an ice cube, and challenge your second-graders to tell you what state of matter each object shows. You might also make a three-column chart and let students give you examples of each state of matter. Encourage your students to bring a state of matter show-and-tell as another idea. Each student will share his object and tell the class what state of matter it shows and how he knows that.
States of Matter Visually
Before science class, fill several ice cube trays with water and add a drop of food coloring to each cube. You might use colored juice instead. Freeze the cubes until they're solid, and then place one in a zip-top bag so you have enough for each student to have one bag. Have your second-graders tell you what state of matter the ice cubes show, and then tape the bags to your classroom window. Over the course of the day, have students observe what's happening in the bags. First, the ice cubes will change from a solid to a liquid, and then the liquid will start forming water vapor, which is a gas. Do a similar activity by having students place frozen dessert pops on a paper plate at the beginning of recess; have them observe how much the desserts change over the course of their playtime.
More Changing Matter
Show second-graders how gas -- in this case water vapor -- changes to a liquid by placing a glass of ice water on your desk. Over the next few minutes, the ice will cause water to condense on the sides of the glass. Show the process of liquid changing to a gas, called evaporation, by leaving the glass of water on your desk for several days. Have the students observe how the water level drops as time passes. If it rains, your students can also witness evaporation in action by watching the puddles dry up as the sun comes out and the rain stops.
A Few More Ideas
Have a solid and liquid party in your classroom. Ask half of the students to bring a liquid, such as juice boxes or water bottles, to share and the other half to bring a solid, such as carrot sticks or granola bars, to share. Have each student share his item and tell what state of matter it is, then divvy up the items and have a little snack. You might also give your students a stack of age-appropriate magazines and have them make states of matter collages. Ask the second-graders to fold their paper into thirds and glue pictures of liquids in one section, solids in another and gases in the third.
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