Acid Rain

Standard Met: Understands atmospheric process and water cycle

Pollution affects all living things. This includes soil and plants—and therefore our food supply. Here’s a simple Earth Day project that demonstrates this. First, begin by planting three identical bean plants in three identical containers. When the plants are a couple of inches high, begin the next part of the experiment. Place ½ cup lemon juice in a clean glass jar. Label its lid #1. In a second jar, mix ¼ cup water and ¼ cup lemon juice. Label this jar’s lid #2. In a third jar, put ½ cup water only. Water one plant with the liquid that’s in jar #1. Water another plant with the liquid in jar #2. Water the last plant with the water in jar #3. (Make sure to use the same amount of liquid for each plant.) The lemon juice represents acid rain. Observe and record what happens to the plants.

Goldfish School

Standard Met: Understands relationships among organisms and their physical environment

You might not be able to teach an old dog a new trick, but with some patience your class can teach a ­goldfish to swim to one side of the tank. Each day, at around the same time, place a large piece of red ­construction paper at one end of the tank. Add food at that end of the tank as well. Eventually the fish will swim to the end of the tank when the red paper is placed there, even when food isn’t present. Before beginning, ask students to predict how long it will take to train the fish. Experiment as a class to see if other colors will also work or if some kinds of fish (such as bettas) learn faster than others. Test how long the fish is able to “remember” the trick.

Knotted Bones

Standard Met: Understands biological evolution and the diversity of life

Provide small groups of students with clean, dry chicken bones. Ask them to examine the bones and write down their observations. Next, have students place the bones in a jar of vinegar (acetic acid) for a day. Remove the bones and discuss changes. The bones will be soft and pliable. Invite the students to tie the bones into a knot. Let the bones dry. After a day, they should be hard again! What’s happening: The bones contain the compound calcium carbonate; this is what makes them hard. When the bones are placed in vinegar, a chemical reaction causes the carbon in the bones to be released. When the bones are taken out and left to dry, they pull back some of the carbon from the carbon dioxide in the surrounding air. Take it further: Investigate what happens when eggs or seashells are immersed in vinegar overnight.

Human Sundial

Standard Met: Understands the composition and structure of the universe and Earth’s place in it

On a sunny day, take students outside in the morning and find a spot on a sidewalk or empty parking lot or playground. Have them draw a chalk outline of their shoes and label it with their name so they can stand in the exact spot again. Next, have kids work in pairs to mark the top of their shadows. Point out where the sun is in the sky (remind them not to look directly at it) and ask what they think will happen to their shadows as the sun moves across the sky. Ask: What will happen to your shadow at noon? Why? (If students are stumped, point out that moving a light source closer to an object can make its shadow grow larger, while moving the light source away can have the opposite effect.) Every hour, have the kids return to their spots and mark the tops of their shadows. Challenge them to predict how seasons can affect the length of shadows. Ask: What does the length of shadows tell us about the sun’s position?

Lava Lamp

Standard Met: Understands the structure and properties of matter

Lava lamps are not only cool to look at—they can be educational, too. This project uses a lot of oil, so you’ll want to divide students into groups to conserve resources. Provide each group with a clean, 1-liter plastic bottle. Carefully pour ¾ cup water into the bottle. Fill the rest of the bottle with vegetable oil (leave about an inch of space at the top). Next, add a dozen drops of food coloring. Then, ask students to predict what will happen if they add a half tablet of Alka-Seltzer. After you’ve added the tablet, invite students to observe and record what happens. Were their predictions correct? Does adding the second half of the tablet cause any changes? Discuss what’s happening: Water molecules are bonding with other water molecules and oil molecules are bonding with other oil molecules, but neither is bonding with the other.

Windowsill Trash

Standard Met: Understands the nature of scientific inquiry

Does heat help break down waste materials faster? Invite students to find out with this eco-oriented project. In a sealable plastic bag, place a variety of biodegradable materials such as a banana peel, lunch meat, and paper. Place identical items in another baggie. Put one baggie on a windowsill in the classroom. Put the second baggie in a classroom refrigerator. Make a graph showing the students’ predictions about which material will start to break down first—the one exposed to the warm sunlight or the one left in a cold, dark place. Have them check each baggie every day and record their observations.

Try this experiment as a variation: Bury a banana peel or other biodegradable material. Leave an identical item aboveground (to keep animals from bothering it, place a wire box over it). Observe which one decomposes quicker, the one underground or the one exposed to the elements. 


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