1. Sink or Float Experiment: Fill a tub with water and gather various objects like coins, paper clips, and feathers. Have students predict whether each object will sink or float and then test their predictions.
2. Leaf Scavenger Hunt: Take students on a nature walk and have them collect different types of leaves. Back in the classroom, help them identify the leaves and discuss their characteristics.
3. Magic Milk Experiment: Fill a shallow dish with milk and add a few drops of different food coloring. Dip a cotton swab in dish soap and touch it to the milk. Watch the colors swirl and mix as the soap reacts with the fat in the milk.
4. DIY Weather Vane: Help students make their own weather vane using a paper plate, a straw, and a pencil. Have them label the directions (north, south, east, west) and observe how the wind changes the direction of the vane.
5. Comparing Ramps: Set up different ramps using books and cardboard. Provide students with various objects and have them test how far each object travels on different ramps. Discuss the concepts of gravity and friction.
6. Seed Germination Experiment: Give each student a plastic bag, a wet paper towel, and a few seeds. Have them place the seeds between the moist paper towel and seal the bag. Observe and discuss the growth process over several days.
7. Shadow Tracing: On a sunny day, take students outside and have them trace their shadows with chalk. Discuss how the position of the sun affects the size and direction of their shadows.
8. Balloon Rocket: Inflate a balloon and attach a string to it. Tape a straw onto the string and thread the string through two chairs. Let go of the balloon and observe how it moves across the string due to the escaping air.

9. Magnetic or Not: Provide students with a variety of objects like paper clips, coins, foam shapes, and magnets. Have them test each object to determine whether it is magnetic or non-magnetic.
10. Fizzing Lemonade: Mix lemon juice with baking soda in a clear cup and observe the fizzy reaction. Discuss the concept of a chemical reaction and how the lemon juice and baking soda create carbon dioxide gas.
11. Water Cycle in a Bag: Fill a small bag with water and seal it. Hang the bag near a sunny window and observe the water cycle as condensation forms inside the bag and then drips back down.
12. Animal Tracks Exploration: Create casts of different animal tracks using clay or plaster. Show students how to identify tracks and discuss how animals leave different tracks based on their foot structure.
13. Rainbow Density Column: Help students create a rainbow density column using liquids like corn syrup, water, vegetable oil, and food coloring. Discuss the concept of density and the different layers formed by the liquids.
14. Melting Ice Experiment: Give students different materials like salt, sugar, sand, and Styrofoam. Have them place a small ice cube on each material and observe which one melts the ice fastest.
15. Solar Oven S’mores: Help students make simple solar ovens using shoeboxes, aluminum foil, and plastic wrap. Have them assemble the ovens and use the power of the sun to melt marshmallows and make s’mores.

These hands-on science activities are designed to engage third-grade students in practical learning experiences that reinforce scientific concepts. Enjoy exploring the exciting world of science with your students!