Fourth Grade Science Experiments (Page 4)

Ball Launcher Challenge

Science Fair Project Idea

Engineering Design Process

Try your hand at this engineering challenge. Can you build a "launcher" device to launch a ball as far as possible and a "receiver" to catch it? Building a receiver provides an extra twist to a traditional catapult project. Add to the challenge by using a limited set of materials to build your machine and calculate a score based on your throw distance and materials used. Read more

Investigate the Kinetics of the Color Changing Iodine Clock Reaction

Science Fair Project Idea

Scientific Method

The iodine clock reaction is a favorite demonstration reaction in chemistry classes that usually requires toxic or hazardous chemicals. During the reaction, two clear liquids are mixed, resulting in another clear liquid. After some time, the solution suddenly turns dark blue. The reaction is called a clock reaction because the amount of time that elapses before the solution turns blue depends on the concentrations of the starting chemicals. In this green chemistry project, you will use a… Read more

Rubber Band Car Challenge

Science Fair Project Idea

Engineering Design Process

In this engineering challenge, you will build a car powered by nothing but a rubber band. The farther the car goes, and the fewer materials you use to build it, the higher your score. The 2024 Science Buddies Engineering Challenge is over, but you can check out this page to see our other past engineering challenges and what this year's challenge will be! Teachers, lesson plan versions of this challenge are also available. Read more

Art Bot: Build a Wobbly Robot That Creates Art

Science Fair Project Idea

Scientific Method

Do you like drawing or painting? What if you could build a robot that creates its own art? In this project, you will create your own Art Bot, a robot with markers for "legs" that wobbles across a piece of paper, creating drawings as it moves. You can then customize your robot to change how it draws. This is a beginner-level project with no robotics experience necessary, so if you want to try building your own robot, this is a great place to start! Read more

Bottled-up Buoyancy

Science Fair Project Idea

Scientific Method

Do you dream about making deep, undersea voyages? Let this project take you 20,000 leagues under the sea! Investigate how submarines dive and surface by changing their buoyancy in this fun project. Read more

Why Does Fruit Turn Brown?

Science Fair Project Idea

Scientific Method

Have you ever wondered why apple slices turn brown once you cut them, or why a yellow banana gets dark spots over time? In this project you will find out why this happens, and how you can keep your apple slices looking fresh! Read more

Build the Best Paper Bridge

STEM Activity

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Bridges come in all shapes, sizes, and materials. What makes a bridge the strongest? Find out in this fun activity as you build simple bridges with paper and test to see how much weight they can hold. Read more

When Science is Sweet: Growing Rock Candy Crystals

Science Fair Project Idea

Scientific Method

Here is a riddle for you: what kind of rock grows? The answer is: rock candy! This delicious candy is actually crystallized sugar and you can "grow" it from a sugar-water solution. In this science fair project you'll learn how to grow your very own rock candy and determine if using seed crystals changes the growth rate of your sugar crystals. Read more

Build a Circuit to Automatically Water Your Plants

Science Fair Project Idea

Engineering Design Process

Have you ever taken care of a plant? It can be tricky to get it right. You have to remember to water it regularly, and you also have to make sure to give it the right amount of water — not too much or too little. What if technology could help? In this engineering project, you will learn how to automate the entire process of watering a plant. Using a soil moisture sensor and a pump, you will build a circuit that will automatically detect when the soil is too dry, add water, and stop when… Read more

Slime Chemistry

Science Fair Project Idea

Scientific Method

Have you ever wondered how fun toys like Silly Putty®, Gak™, and Slime™ are made? These products are so much fun because of the properties of polymers, which make them delightfully bouncy, stretchy, sticky, moldable, breakable, hard, soft, and just plain fun! In this science project you can be the developer of your own slime product by changing the amount of a key ingredient. By observing the physical properties of your results, you can choose the best recipe for your new… Read more

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