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55 Third Grade Science Tasks for the Classroom or Science Truthful

January 10, 2023
Homeschooling Blogs

Want to see your third grade science students’ eyes light up? Tell them they’re going to do an experiment! These activities are easy enough for any classroom or kitchen, and they’re full of science concepts kids need to learn.

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1. Make glowing flowers

Flowers with their vascular systems glowing blue and green under black light

This one will make kids’ eyes pop out of their head! Use highlighters and a blacklight flashlight to reveal the vascular system of flowers.

Learn more: Tamara Horne

2. Flick pennies to learn about inertia

Third grade science student flicking an index card out from underneath a stack of pennies suspended over a cup of water

This is one of those science experiments that kind of looks like magic, but it’s really all about the laws of motion. It might take a little practice to get the index card flick just right, but the results are always cool!

Learn more: Frugal Fun for Boys and Girls/Penny Inertia

3. Find your way with a DIY compass

DIY compass made from a needle floating in water

Here’s an old classic that never fails to impress. Magnetize a needle and float it on the water’s surface, and it will always point north.

Learn more: STEAM Powered Family

4. Separate salt and pepper with static electricity

Spoon charged with static electricity separating pepper from salt

When you mix up salt and pepper, you’d think it would be almost impossible to separate them again. But using a little static electricity and a plastic spoon, it’s surprisingly simple.

Learn more: Science Kiddo

5. See the temperature rise in a chemical reaction

Steel wool in vinegar in a beaker, with a thermometer (Third Grade Science)

When iron meets oxygen, rust forms. Use vinegar to remove the protective coat from steel wool and watch the temperature rise from the chemical reaction.

Learn more: 123 Homeschool 4 Me/Thermal Reaction

6. Design a candy-delivery machine

Candy delivery machine built of drinking straws (Third Grade Science)

Learn about inclined planes with this fun simple-machines project. Kids can get creative and develop any kind of delivery system they like!

Learn more: 123 Homeschool 4 Me/Candy Machine

7. Mix up your own putty slime

Blob of bright pink slime sitting on clear zipper bags (Third Grade Science)

Kids adore slime, and it’s actually a terrific way to teach them about polymers. This third grade science experiment plays around with different formulations to create slime with varying properties.

Learn more: Science Buddies/Slime Chemistry

8. Craft fossils from glue

Twig-shaped imprint in clay filled with glue, next to a twig

Create clay molds of natural objects, then fill them with school glue to make your own “fossil” casts. This is a great project to try before a trip to the natural history museum.

Learn more: Fossils

9. Float an iceberg

Paper boat floating in a dish with a large chunk of ice

Use a balloon to make an iceberg, then float it in a dish of water to learn how much you can see above and below the waterline. Try experimenting with salt water to see how the density changes things.

Learn more: Science Sparks/Icebergs

10. Defy gravity with magnets and paper clips

Cardboard strip supported by colorful blocks, with paper clips suspended from magnets underneath (Third Grade Science)

Magnets are always a hit in the classroom. Use this simple experiment to discover more about gravity and the effects of magnets on metal objects.

Learn more: Buggy and Buddy/Magnet Gravity

11. Take a Play-Doh core sample

Playdough colors layered, with holes punched in the top green layer

Learn about the layers of the Earth by building them out of Play-Doh. Then students can take a core sample with a straw. (Love Play-Doh? Get more learning ideas here.)

Learn more: Line Upon Line Learning

12. Spin a disappearing color wheel

Spinning disk on a string, showing a beige color

Color a paper disk with the six primary and secondary colors. Then thread a string through the middle and make it spin. The colors will seem to disappear!

Learn more: Crafts Guru on YouTube

13. Crystallize some pretty fall leaves

Colorful fall leaves covered in crystals (Third Grade Science)

Every kid loves making crystals. In this third grade science project, learn about supersaturated solutions by crystallizing some colorful fall leaves. Then use them as fall classroom decor!

Learn more: STEAMsational

14. Find a robot’s center of gravity

Print out, cut, and color this free paper robot. Then glue some coins to the back and have your students try to find its center of gravity!

Learn more: Buggy and Buddy/Balancing Robot

15. Find the most waterproof roof

Third grade science student spraying water on a LEGO house with a wood roof

Calling all future engineers! Build a house from LEGO, then experiment to see what type of roof prevents water from leaking inside.

Learn more: Science Sparks/Waterproof Roof

16. Run marble races with pool noodles

Pool noodle cut in half horizontally, with cardboard finish line sign at one end

Crack open a pool noodle or two and create your own marble racetracks. Experiment with angles, force, and surface materials to find the fastest way to get the marble to the bottom. (Find more fun ways to use pool noodles in the classroom here.)

Learn more: The Techy Teacher

17. Make sun prints to display

Shadow prints of scissors and key on blue sun print paper (Third Grade Science)

You’ll need special sunprint paper for this project, but it’s inexpensive and easy to find. Kids learn about chemical reactions as they use the power of the sun to create unique works of art.

Learn more: Science Buddies/Sunprints

18. Make your own bouncing bubbles

Have your third grade science students put on gloves and watch the bubbles bounce! Then encourage them to experiment with their own bubble solution. Try different soaps, mixing up the ratios to make the strongest bubble possible.

19. Build a better umbrella

Cupcake wrapped balanced upside-down on wood craft sticks, with water being poured on top

Challenge students to engineer the best possible umbrella from various household supplies. Encourage them to plan, draw blueprints, and test their creations, using the scientific method.

Learn more: Raising Lifelong Learners

20. Project the stars on your ceiling

Third grade science student poking holes in the bottom of a paper cup in the shape of a constellation

Use the video lesson in the link below to teach third grade science students why stars are only visible at night. Then create a DIY star projector to explore the concept hands-on.

Learn more: Mystery Science

21. Blow through a water whistle

Third grade science students blowing through a straw into a cup of water

Learn about the science of sound with this easy experiment. Kids will love building their own whistles from straws and a glass of water.

Learn more: My Baba

22. Construct a marshmallow catapult

Third grade science student playing with a catapult made of a tissue box and pencils

Fling some sweet treats in the name of science! All you need is an old tissue box, pencils, rubber bands, and a few other supplies to learn about trajectory, air resistance, gravity, and more.

Learn more: Frugal Fun for Boys and Girls/Tissue Box Catapult

23. Experiment with ice, salt, and water temperature

Two glasses of water, one with ice and a thermometer

This simple experiment requires only water, ice, salt, and a thermometer. Your third grade science class can explore how ice and salt affect the temperature, a simple but effective lesson on heat transfer and freezing points.

Learn more: 123 Homeschool 4 Me/Ice, Salt, and Temperature

24. Blow bubbles inside bubbles inside bubbles

Large bubble with several smaller concentric bubbles inside

If there’s a more fun way to learn about surface tension than bubbles, we haven’t found it yet! Create a soap solution by using dissolved sugar and discover more about elasticity and volume as you blow bubbles inside bubbles inside bubbles …

Learn more: Ronyes Tech

25. Experiment with colors

Coffee filter flowers dyed different colors with text reading Spring Science Flowers Chromatography Science Project

Play around with colors, mix them together, and then use a little science magic to pull them apart again. This chromatography science project requires only simple supplies like coffee filters and markers.

Learn more: 123 Homeschool 4 Me/Chromatography

26. Understand the science behind bath bombs