Construct a Volcano

• Volcano
  
  Creating a volcano and watching it erupt is an educational activity for older children, particularly those in middle school. When your lesson plan covers volcanoes and volcanic activity, have children construct their own volcanoes. A simple volcano to make is a dough volcano.
  
  Find a cardboard box or lid. A lid with a lip that is about 3 or 4 inches deep works well, or you could cut the sides of a regular box down. In a large bowl, mix 6 cups of flour, 2 cups of salt, 2 cups of water and 4 tablespoons of cooking oil to form dough. Place a plastic soda bottle in the center of the box lid. Use the dough to create a mountain around the bottle. Be sure to leave the bottle opening exposed. Add food coloring to make your volcano more lifelike. Pour water into the bottle and add 2 teaspoons of baking soda. When you want your volcano to erupt, add vinegar straight into the hole.
  
  

White Light

• Colored Paper
  
  Use colored paper and white paper to teach seventh-graders about white light. Explain about color by holding up a sheet of colored paper. For example, if the sheet is red, explain that white light hits the paper and red bounces back for us to process. The other colors are absorbed into the paper, but all we see is red.
  
  Give each student a small piece of colored paper and a regular sheet of plain white paper. Have the student stare at the colored paper for about one minute. Have him remove the colored paper and put the white paper in its place. The student should still see the image of the colored sheet on the white paper. When you look at a color for a length of time, the retinal cones become tired and imprint this color in the eyes. When you immediately stare away, especially on white paper, you will still see the imprinted image of the colors.
  
  

How to Make a Working Thermometer

• Homemade thermometer
  
  Teach seventh-graders about temperature and how a thermometer works by having them construct one. They will need tap water, rubbing alcohol, an 11-ounce water bottle, food coloring, a clear drinking straw and modeling clay. Pour equal amounts of rubbing alcohol and water into the bottle until it is about one-quarter full. Add a few drops of food coloring.
  
  Place the straw in the bottle but do not allow it to touch the bottom and do not allow anyone to drink the liquid. Use the modeling clay to seal the bottle and hold the straw in place. Hold your hands on the bottle to warm the liquid and watch what happens.