Science Projects for 3rd Graders (Free Printables)

Looking for fun and easy science projects for 3rd grade? You’re in the right place! This guide features over 50 hands-on science experiments and science fair ideas perfect for home or classroom.

What Do 3rd Graders Learn in Science?

In 3rd grade, kids are ready to investigate the world around them using the scientific method. They’re curious, eager to ask questions, and capable of thinking more deeply about cause and effect.

Common science topics in 3rd grade include:

Force and Motion: gravity, friction, air resistance
Magnetism and Electricity: Learn about how magnets and simple circuits work@
States of Matter: solids, liquids, and gases
Ecosystems: plants, animals, and their relationships
Weather and Climate: Make homemade weather instruments
Earth Science: erosion, the rock cycle, space, and water systems
Scientific Method: Learn the steps of the scientific method, how to write a hypothesis, and choose variables. Useful for kids of various grade levels!
Science Fair Skills: Find easy science fair projects, tips, and board ideas

These experiments are designed to build confidence and critical thinking skills, and most are easy enough for teachers or parents to facilitate without special equipment!

🔎 Explore making your own scientific models too!

Best 3rd Grade Science Fair Projects

Looking for project ideas that really shine at the science fair? These experiments are perfect for using the scientific method and exploring testable questions with real results. Kids can change variables, record observations, and present what they discover!

What Colors Absrob Heat Best: Test which colors absorb heat better.

Friction Science Experiment: Compare how objects slide across different surfaces.

Apple Browning Experiment: Find out which liquids slow browning the best.

Red Cabbage pH Indicator: Explore the pH of everyday household liquids.

Milk Plastic (Casein): See if different types of milk change the plastic results.

Plant Growth Experiment : Compare plant growth under different conditions.

Does Color Affect Taste?: Investigate how color may influence flavor perception.

Build a Barometer: Track pressure changes and compare to weather conditions.

Stormwater Runoff: Model how different surfaces affect runoff and pollution.

Oil Spill Clean Up: Test which materials clean oil from water most effectively.

Paper Towel Absorbency: Compare brands to determine the most absorbent.

Chromatography with Markers: Discover how different markers separate into colors.

Easy 3rd Grade Science Experiments and Projects By Category

These simple activities explore everything from motion and magnetism to weather, animal life cycles, and chemical reactions, with minimal prep and materials you already have.

Click on any title below to explore the complete activity with step-by-step instructions, supply list, science explanation, and printable worksheets!

Forces and Motion

Introduce students to the basics of physics with these hands-on experiments exploring force, motion, and energy. Through interactive challenges, kids will learn how things move, what affects that motion, and how to test their predictions.

🔎 Make sure to grab this free force and motion activity pack to get started.

Air Resistance Experiment: Test how paper shape affects how slowly it falls with air resistance.
Mini Paddle Boat: Explore force and motion by building a rubber band-powered paddle boat.
Popsicle Stick Catapult: Launch items into the air while learning about stored energy and force.
Engineer a Roller Coaster: Use cardboard and creativity to explore gravity, friction, and energy.
Bottle Rocket: Create a baking soda and vinegar reaction to launch a film canister rocket.
Alka-Seltzer Boat: Propel a simple boat using fizzing reactions from Alka-Seltzer tablets.
Friction Science Experiment: Discover how different surfaces affect motion by testing friction.
Balloon Rocket: Use the power of air to launch a balloon along a string and explore thrust.
Popsicle Stick Chain Reaction: Build a chain reaction with popsicle sticks to learn about tension and stored energy.
Static Electricity Butterfly: Use static electricity to make a butterfly’s wings move without touching them!
Balloon-Powered Car: Design a car that moves using the thrust from a balloon.
Newton’s Laws Experiments: Learn more about Newtons Laws of Motion!

🔎 Make sure to grab this potential and kinetic energy pack to get started.

Physical Science and Engineering

Let kids become young engineers and physicists with projects that build, test, and explore the properties of materials, light, magnetism, and electricity. These physics experiments and activities are perfect for fostering creativity and problem-solving skills.

Magnet STEM Projects: Explore magnetic fields and forces with fun hands-on experiments.
Color Wheel Spinner: Spin colors together to reveal white light in a fun physics demo.
Electric Cornstarch: Use static electricity to make cornstarch jump and dance.
Paper Towel Absorbency Test: Test which paper towel brand absorbs the most water.
Electricity Experiments – Circuits: Build simple circuits to learn how electricity flows.
Lava Lamp Experiment: Create a bubbling lava lamp using oil, water, and fizzing tablets.
Materials Properties: Learn about the properties of materials and apply them to science projects.
Light Experiments: Explore reflection, refraction, and shadows
Insulation Experiment: Test which materials are best at keeping things warm.

Chemistry and Reactions

Explore the magic of chemical reactions using everyday materials. These chemistry experiments help students understand how substances interact, change, and create new forms—plus they’re just plain fun!

🔎 You can learn more about chemical changes, physical changes, and phase changes!

Apple Browning Experiment: Investigate which liquids prevent apples from browning fastest.
Red Cabbage pH Indicator: Make a natural pH indicator from cabbage to test common household liquids.
Vinegar and Milk Plastic: Transform milk into a plastic-like material using vinegar.
Emulsions Science: Discover why oil and water don’t mix and make a homemade salad dressing.
Mentos and Coke Reaction: Witness an explosive geyser when Mentos meets soda!
Chromatography Lab: Separate ink colors using a simple paper chromatography method.
Sugar Cube Absorption Test: Test different materials to see which best slows sugar cube dissolving.
Slime Science: Mix up slime and explore chemical reactions and polymers.
Acid Rain Plant Test: Test how acidic liquids affect plant health using flowers and vinegar.
Alka Seltzer Rocket: Explore chemical reactions through rockets, boats, and homemade lava lamps.
Carbon Sugar Snake: Watch a fiery chemical reaction turn sugar into a growing carbon snake.
Cocoa Hydrophobia Experiment: See why cocoa powder resists mixing with water in this hydrophobic demo.
Baking Soda and Vinegar Experiments: Make a volcano, bottle rocket, and more!
Skittles Experiment: Explore solubility, density, and diffusion with a favorite candy.

Earth and Weather Science

Help kids investigate natural Earth processes and weather patterns with simple experiments. From erosion and pollution to predicting the weather, these activities connect science to the world around them.

🔎 Explore more here with Earth Science Activities, Ocean Activities, Space Activities, and Weather Activities for Kids

Coastal Erosion Model: Use sand and water to simulate and study beach erosion.
Freezing Salt Water: Compare how fresh and saltwater freeze and learn about freezing points.
Salt Water Density: Explore how different object sink and float with salt water.
Water Filtration Experiment: Build your own water filter to explore clean water systems.
Build a Weather Station: Make simple instruments to measure temperature, wind, and precipitation.
Pinecone Weather Station:Use a pinecone to predict weather changes by watching how it opens or closes.
Stormwater Runoff Model: Demonstrate how pollution travels through runoff during heavy rain.
Oil Spill Experiment Cleanup: Try different methods to clean oil from water and protect the environment.
Crayon Rock Cycle: Simulate the rock cycle by melting, cooling, and pressing crayons.
Solar System Activities: Learn about the planets with hands-on solar system models and crafts.
Playdough Layers of Earth: Create a colorful Earth model from playdough to explore its layers.
Soil Layers Model Printable: Build a layered soil model and learn about different types of soil.

Life Science and Biology

Explore living things by engaging in experiments on plants, animals, and ecosystems. These activities are great for exploring life cycles, adaptations, and the incredible diversity of nature.

🔎 Look for more animal science activities here.

🔎 Look for more plant experiments here.

Food Chains Activity: Understand how energy flows through animals and plants in a food chain.
Plant and Animal Life Cycles: Explore the life cycles of insects, amphibians, birds, and more.
Animal Adaptations Activities: Discover how animals adapt to survive in different environments.
Germinate Seeds in a Bag: Watch seeds sprout and grow using just a plastic bag and paper towel.
Plant Transpiration Experiment: Explore how plants release water through their leaves using a simple setup.
Bread Mold Experiment: Observe how mold grows over time and learn about fungi and decomposition.
Celery and Food Coloring Experiment: Discover how plants absorb water through their stems using colored water.
Dissecting Flowers: Identify the parts of a flower by taking one apart and labeling its structures.
Animal Classification Activity: Sort animals into different groups based on shared characteristics.
Vertebrates and Invertebrates Activity: Learn the difference between animals with backbones and those without.
Does Color Affect Taste?: Test if our senses work together by seeing if food color changes how something tastes.
Germ Science Experiment: Explore how germs spread and the importance of washing hands with fun visuals.
Leaf Chromatography: Separate pigments in leaves and discover what colors are hiding inside.