Chlorophyll is a chemical that plants make, which gives them their green color. Plants need light in the making chlorophyll. Locate an area of lawn where the grass is all green. Lay a 3-foot-square piece of plywood on the lawn. Once a day, lift up the wood and examine the grass underneath. Write down any change in color as you compare it to the surrounding grass. Record how many days it takes of sunlight deprivation before the grass loses almost all of its green color. Then, remove the wood and watch the patch of grass every day to see if the grass recovers, and if so, how many days it takes for the green color to return.
Look at a shiny new copper penny and an old, dull, tarnished penny. Tarnish is the result of a chemical reaction over time between air and the copper. Cover the tarnished penny in tomato sauce. After a half hour, rinse the penny in clean water, and observe the changes to the tarnished penny.
Hypothesize that you can make a bubble solution that will make bubbles just like a commercially available bubble product. Pour 3/4 cup of warm water into a bowl. Add 4 teaspoons of liquid dish detergent. Stir in 2 level tablespoons of confectioners sugar. Using a "bubble wand" that comes with a bottle of store-bought "bubble stuff," dip the wand into the homemade bubble solution and blow bubbles. Compare the bubbles you can make with your homemade solution to the commercial bubble product.
When water freezes, it expands and takes up more room. If rain fills cracks in roadways and freezes, it can cause the cracks to get worse. Hypothesize that a given amount of water will take up more room (volume) when it's frozen than when it's in a liquid state. Fill an empty soup can with water to as close to the top as you can without it spilling. Place it in your refrigerator's freezer overnight. Examine it in the morning to see if the volume has expanded to the point that the ice has risen up and above the top of the can.
When you turn on a lamp or a flashlight, you can see the light from the bulb and you can see objects illuminated by the light. But you don't see the actual beam of light as it travels through the air to reach objects in the room. In a dark room, place a lit flashlight on a table. To make the light beam visible, shake several facial tissues in front of the flashlight. The light beam reflects off the fine tissue particles in the air, making the beam visible.
The sun is about 93 million miles away, but its rays make life possible here on Earth. Sunlight can have an effect on different materials. Take 2 strips of an old white T-shirt. In a sink, dip one cloth strip in beet juice and one in purple grape juice. Cut a strip of newspaper. Lay all three strips in a sunny window. Record any changes in the strips every day, and note how exposure to the sun affects the strips.