Third Grade Science Projects (386 results)

Science Buddies' third grade science projects are the perfect way for third grade students to have fun exploring science, technology, engineering, and math (STEM). Our third grade projects are written and tested by scientists and are specifically created for use by students in the third grade. Students can choose to follow the science experiment as written or put their own spin on the project.

For a personalized list of science projects, third graders can use the Science Buddies Topic Selection Wizard. The wizard asks students to respond to a series of simple statements and then uses their answers to recommend age-appropriate projects that fit their interests.

Let us help you find a science project that fits your interests, with our Topic Selection Wizard.

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Balloon-Powered Car Challenge

Science Fair Project Idea

Engineering Design Process

Do you think you could build a car powered by nothing but air? A balloon-powered car is pushed forward by air escaping from a balloon, and it is fun and easy to build with materials you already have around your house. Can you imagine how you would want your own balloon-powered car to look? Can you design a car that will travel as far as possible? You can even measure your car's speed using your smartphone and a special sensor app. Get ready to grab some simple supplies to bring your idea to… Read more

How to Turn a Potato Into a Battery

Science Fair Project Idea

Scientific Method

Imagine telling your friends about your latest science project: using a battery to make a light turn on. You might get some blank stares...sounds a little boring and basic, right? Now tell them you will do it with a potato! Yes, you can actually use fruits and vegetables as part of an electric power source! Batteries power many things around you, including cell phones, wireless video game controllers, and smoke detectors. In this science project, you will learn about the basics of battery… Read more

Landslides: What Causes Rocks to Slide Down a Slope?

Science Fair Project Idea

Scientific Method

Landslides are powerful geological events that happen suddenly, causing fear in people who live in areas with unstable hills, slopes, and cliff sides. Landslides damage the surrounding habitat and can destroy homes in their path. But what causes landslides? Can slides happen on any slope, or do slopes have to have certain characteristics, such as a steep angle and a specific material mass? In this geology science project, you will learn about the different types of landslides and the… Read more

Exploring Nanotechnology: Fold, Roll, & Stack Your Way to Super-Strong Materials

Science Fair Project Idea

Scientific Method

Advertisements for high-tech sports gear or the latest and greatest outdoor material promise lighter and stronger products every season. Is it a scam? How can engineers keep creating materials that are both lighter and stronger than anything known so far? The answer is in the nanoscale! Using nanotechnology, scientists can play around with the detailed structure of matter, leading to a whole new range of materials, some with amazing qualities. In this science project, you will get a glimpse… Read more

Why Aren't All Medicines Pills?

Science Fair Project Idea

Scientific Method

No one likes shots, so why don't we swallow all our medications? In this science project, you will use a model to explore one challenge behind making medications we can quickly swallow, using insulin (a medication taken by some diabetes patients) as an example. Will your medication be functional after spending time in an environment similar to the stomach? Read more

Design Your Own Slime

Science Fair Project Idea

Engineering Design Process

There are many different kinds of slime out there. Some slime is runny and liquid-like; other slime is thick and rubbery. Some slime glows in the dark, some is fluffy, and some is even magnetic! What set of properties makes the best slime? What kind of slime would you choose to make if you were selling slime as a toy in your own "slime shop"? In this project, you will experiment with different slime recipes and try to perfect one to make slime with the exact properties you want! Read more

Tallest Paper Tower Challenge

Science Fair Project Idea

Engineering Design Process

In this engineering challenge, you will use limited materials to build a paper tower as tall as possible, but there's a twist! Your tower must also support a heavy weight at the top without collapsing. Looking for inspiration? You can see how other students have tackled this and other annual Science Buddies Engineering Challenges. Teachers, lesson plan versions of this challenge are also available. Read more

Build a Floating Maglev Train

Science Fair Project Idea

Scientific Method

How can you make a train without wheels? By using magnets! In this project you will build a magnetic levitation ("maglev" for short) train that floats above a magnetic track. How much weight can you add to the train before it sinks down and touches the track? Read more

Fighting the Flu: How Your Immune System Uses Its Memory

Science Fair Project Idea

Scientific Method

Being sick is no fun, especially when your friends are doing exciting activities that you have to miss out on. Thankfully, common illnesses usually last for just a few days, and then you start to feel better. Why is this? It is thanks to the immune system, which is a group of special organs and cells in your body that constantly work to keep you healthy. In this science project, you will make a simple model to investigate how the immune system defends the human body from common illnesses, and… Read more

How Far Will It Fly? Build & Test Paper Planes with Different Drag

Science Fair Project Idea

Scientific Method

Just one sheet of paper can lead to a whole lot of fun. How? Paper planes! All you have to know is how to fold and you can have a simple plane in a matter of minutes! But what design should you use to build the best plane? In this aerodynamics science project, you will change the basic design of a paper plane and see how this affects its flight. Specifically, you will increase how much drag the plane experiences and see if this changes how far the paper plane flies. There is a lot of cool… Read more

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