50 Sensational 7th Grade Science Fair Projects and Classroom Activities

Mummification, oxidation, electroplating, and more!

Collage of 7th grade science projects, including Oreo mitosis models and electroplating a coin
We Are Teachers; Ballin With Balling; KiwiCo

Engage every student with these 7th grade science fair projects, whether they’re interested in biology, chemistry, physics, environmental science, or any other discipline. Plus, find interesting classroom demos, experiments, and hands-on activities to spice up your lesson plans!

To make it easier to find classroom activities or science fair ideas for 7th grade, we’ve rated all the projects by difficulty and the materials needed:


  • Easy: Low or no-prep experiments you can do pretty much anytime
  • Medium: These take a little more setup or a longer time to complete
  • Advanced: Experiments like these take a fairly big commitment of time or effort


  • Basic: Simple items you probably already have around the house
  • Medium: Items that you might not already have but are easy to get your hands on
  • Advanced: These require specialized or more expensive supplies to complete

Jump to:

Biology and Ecology Science Fair Ideas for 7th Grade


Want to learn more about animals or human behavior, the environment around you, or other life science topics? Try these 7th grade science fair projects.

Learn whether color affects memory

A tablet and smartphone with screens showing text

Difficulty: Easy / Materials: Medium

Can certain colors improve your memory? This experiment explores that idea using different text, background colors, and blue light settings on devices.

Learn more: Colors and Memory at Education.com

Explore how sugary drinks affect teeth

Four colored cups containing different liquids, with an egg in each
Feels Like Home

Difficulty: Easy / Materials: Medium

The calcium content of eggshells makes them a great stand-in for teeth. In this experiment, students use eggs to determine how soda and juice stain the teeth and wear down the enamel. (Bonus: Have students try different toothpaste and toothbrush combinations to see how effective they are.)

Learn more: Eggshell Experiment at Feels Like Home

Extract DNA from an onion

Difficulty: Medium / Materials: Medium

Learn how to extract DNA from an onion (most of what you need you can find at home, and you can get 95% ethanol at Amazon). Then, turn it into an experiment by applying the theory to other fruits or vegetables to see if you can get similar results.

Stretch your mind with a flexibility experiment

Three students lying on their backs stretching one leg in the air while another student stands nearby
We Have Kids

Difficulty: Medium / Materials: Basic

Find out how important stretching really is by comparing the flexibility of willing test subjects before and after stretch exercises. This is a great experiment for fitness fans.

Learn more: Flexibility Experiment at We Have Kids

Construct a DIY grow box

DIY plant grow box made with aluminum foil
Uplifting Mayhem

Difficulty: Medium / Materials: Medium

Design a grow box using a cardboard box, foil, and a plug-in light socket. Then, use it for all kinds of plant-based science fair ideas for 7th grade students.

Learn more: DIY Grow Box at Uplifting Mayhem

Collect and control biofilm

Two plastic milk jugs sitting by a sink, covered with green film
The Homeschool Scientist

Difficulty: Medium / Materials: Medium

Bacteria that accumulate on objects in the water form a substance called biofilm. In this 7th grade science fair project, students build an apparatus to collect biofilm and then experiment with ways to reduce the amount of biofilm that accumulates over time.

Learn more: Biofilm Experiment at The Homeschool Scientist

See if caffeine helps you type faster

Difficulty: Easy / Materials: Medium

People seek out a jolt of caffeine when they’re feeling sluggish, but does it really help them perform better? This 7th grade science fair project tasks students with answering that question using the scientific method.

Find out if all plants are phototropic

Difficulty: Easy / Materials: Medium

You probably already know that many plants grow toward the light. But do all of them respond in the same way? Test several types of plants to find out.

Devise a water filtration system

Bottle of powdered activated charcoal next to two jars of colored water
The Homeschool Scientist

Difficulty: Medium / Materials: Medium

Plenty of homes use water filtration systems these days, but how do they really work? This chemistry experiment explores how charcoal filters impurities from drinking water.

Learn more: Water Filtration at The Homeschool Scientist

Determine whether text abbreviations are a new language

Cell phone and notebook with list of texting terms

Difficulty: Medium / Materials: Basic

Kids are fluent in text-speak, but does it really count as a whole new language? In this 7th grade science fair project, students research language and the history of texting, then compile a texting glossary and consider texting’s practical applications.

Learn more: Text Language at Education.com

Chemistry Science Fair Ideas for 7th Grade

If you’re fascinated by test tubes, beakers, and Bunsen burners, check out these interesting 7th grade science fair projects and ideas.

Design your own slime

Difficulty: Easy / Materials: Medium

Chances are good your students already love making and playing with slime. Turn the fun into an experiment by changing the ingredients to create slime with a variety of properties, from magnetic to glow-in-the-dark!

Copper-plate some coins

9 volt battery with electric wires running to a penny, with a cup of blue liquid

Difficulty: Easy / Materials: Medium

Students need just a few simple supplies to perform electroplating, but the results are always impressive. (Get copper strips and 9V battery snap connectors with alligator clips on Amazon.) Turn this into a 7th grade science fair project by changing up the variables (does temperature matter?) or items being electroplated.

Learn more: Electroplating at KiwiCo

Swab and test for germs

Petri dishes marked floor, fridge, sink, and more, each showing some bacterial growth
Angelic Scalliwags

Difficulty: Medium / Materials: Medium

Germ experiments are one of the most popular science fair ideas for 7th grade students. Swab household items, school supplies, and more to discover what’s living on the items around you.

Learn more: Germ Experiment at Angelic Scalliwags

Spherify your favorite beverage

Difficulty: Medium / Materials: Medium

Spherification is a hot trend in top restaurants, but 7th grade science students can easily replicate it at home with a spherification kit. This is a cool chemistry experiment, and tasty too!

Test calorie counts in packaged foods

Difficulty: Medium / Materials: Medium

Ever wonder how scientists determine how many calories are in your food? Try this experiment to find out!

Explore mummification

Difficulty: Easy / Materials: Medium

First, learn how to mummify a hot dog using baking soda as a desiccant. Then, experiment with other desiccants or items to turn this into a bona fide experiment.

Play around with oxidation

Series of paper cups containing small items like a penny, paper clip, screw, and more
Teach Beside Me

Difficulty: Easy / Materials: Medium

Can you find a way to slow or prevent oxidation (rusting)? This is one of those 7th grade science fair ideas that’s simple in concept but has lots of practical applications.

Learn more: Oxidation Experiment at Teach Beside Me

Blow hot or cold bubbles

Frozen soap bubble on snowy branches
ulleo via Pixabay

Difficulty: Easy / Materials: Medium

Blowing bubbles may sound like too much fun for a science project, but when conditions like temperature are altered, the experimental part kicks in. What conditions do you need to blow a bubble that freezes?

Learn more: Bubble Life & Temperature at ThoughtCo.

Whip up some eggshell chalk

Pink sidewalk chalk stick sitting on a paper towel

Difficulty: Medium / Materials: Medium

Use the calcium in eggshells to make your own sidewalk chalk. Then, tinker with the recipe to see if you can make the chalk last longer, resist water, or other variables.

Learn more: DIY Chalk at Kidspot

See the effect of acid rain on plants

Two white tulips in glasses of water. One is healthy and one is wilted.
STEAM Powered Family

Difficulty: Easy / Materials: Basic

This simple project tests whether acid rain has any effect on plant life, using vinegar in place of fossil fuels. Experiment with different acid concentrations and pH levels for a more advanced version.

Learn more: Acid Rain Experiment at STEAM Powered Family

Physics and Engineering Science Fair Ideas for 7th Grade

Explore the laws of motion, the science of energy, or STEM challenge engineering ideas through 7th grade science fair projects like these.

Drive a balloon-powered car

Balloon-powered car made from cardboard (Seventh Grade Science)

Difficulty: Medium / Materials: Medium

Engineer a balloon-powered car using basic materials from around the house (even the wheels are bottle caps!). Experiment to see how far or fast you can make the car go.

Learn more: Balloon Car at Prolab

Construct a geodesic dome

Difficulty: Medium / Materials: Basic

Budding engineers will love designing, building, and testing the strength of the fascinating geodesic dome. This experiment requires nothing more than newspaper and masking tape!

Design a solar oven

Pizza boxed turned into a solar oven, propped open with graham crackers, chocolate, and marshmallows inside
Children’s Science Center

Difficulty: Medium / Materials: Medium

Students experiment with the best way to build a solar oven, exploring thermal energy, reflection, convection, and other physics concepts. They can serve up their experiment results along with their final reports!

Learn more: Solar Oven at Children’s Science Center

Lend a helping hand

Difficulty: Medium / Materials: Medium

This is a great individual or group 7th grade science project, as it encourages students to use and hone their design and engineering skills to make a working model of a hand. If you’ve got robotics skills, take this project to a more advanced level.

Build a Da Vinci bridge

Difficulty: Medium / Materials: Medium

There are plenty of bridge-building experiments out there, but this one is unique. It’s inspired by Leonardo da Vinci’s 500-year-old self-supporting wooden bridge. Build a model and test the amount of weight it can hold, or craft a full-size version to put Da Vinci’s plan into action.

Construct a water clock

Several small bowls next to a water clock made from a jar of water, styrofoam cup, wood craft stock, and jingle bell
STEAM Powered Family

Difficulty: Easy / Materials: Medium

You’ll blow your 7th grade science students’ minds when you tell them they’re going to build a clock using engineering that’s been around for thousands of years. The supplies are simple, but the results are pretty neat!

Learn more: Water Clock at STEAM Powered Family

Generate electricity

Difficulty: Medium / Materials: Medium

In this science fair project, kids build a generator from scratch. Turn it into an experiment by varying the materials to see if you can increase the amount of energy it produces.

Test the elasticity of balloons

Difficulty: Easy / Materials: Medium

Explore whether heat and cold have an effect on elasticity using balloons. Try this with other materials too to expand the project. (Find more balloon science here!)

Freeze water in an instant

Difficulty: Easy / Materials: Medium

Explore the concept of nucleation (the process of chain reactions) by turning water into ice in seconds! Make this a 7th grade science fair project by trying the same process with other liquids.

Auto-feed your pet

Difficulty: Advanced / Materials: Advanced

Can you build a device that feeds your pets automatically? Even better, can you make it inexpensive and easy for others to build too? This project has real practical applications.

7th Grade Science Classroom Demos, Experiments, and Hands-On Activities

Use these classroom activities to teach human biology, mechanical engineering, and more physics and chemistry concepts in engaging and exciting ways.

Use Oreos to teach mitosis

Two Oreo cookies opened up and pushed together to model cell mitosis
Ballin With Balling

Difficulty: Medium / Materials: Medium

A 7th grade science activity that doubles as a sweet treat? Your students are going to love this activity using Oreo cookies and colorful sprinkles to make cellular mitosis models.

Learn more: Oreo Mitosis at Ballin With Balling

Twist pipe cleaners to explore meiosis

Cellular meiosis model made with pipe cleaners, beads, and string
Science Prof Online

Difficulty: Medium / Materials: Medium

Meiosis is similar to mitosis, but it’s specific to the production of gametes. These hands-on models use basic materials like pipe cleaners and beads to make the process easier to visualize.

Learn more: Meiosis Models at Science Prof Online

Teach about “Homer-o-stasis”

Ring stand with a plastic cup and a picture of Homer Simpson, with various chemicals, colored cups, and a bin of flour
The Trendy Science Teacher

Difficulty: Medium / Materials: Advanced

This is such a fun way to teach kids about the concept of homeostasis! Get all the instructions you need at the link.

Learn more: Homer-o-stasis at The Trendy Science Teacher

Sort jelly beans to learn genetics

Jellybeans sorted into two plastic cups labeled "father" and "mother" (Seventh Grade Science)
The Owl Teacher

Difficulty: Easy / Materials: Medium

If you’re learning about how genetic traits are passed along from parent to child, try this jelly-bean demo. When you’re finished, you can enjoy a sweet treat!

Learn more: Jelly Bean Genetics at The Owl Teacher

Design a pinball machine

Student-created pinball machine made from cardboard box, paper cups, and other basic supplies
Student Savvy

Difficulty: Medium / Materials: Medium

Give your class basic supplies like rubber bands, plastic cups, and cardboard boxes. Then challenge them to create their very own pinball machines!

Learn more: Pinball STEM Challenge at Student Savvy

Conduct a carbon cycle lab activity

Series of test tubes filled with liquid ranging from yellow to green to blue
Science Lessons That Rock

Difficulty: Medium / Materials: Advanced

If you’ve got access to some basic chemicals, conduct this lab that helps students see the carbon cycle in action using their own breath.

Learn more: Science Lessons That Rock

Make a tea bag float on air

Three empty teabags burning
Coffee Cups and Crayons

Difficulty: Easy / Materials: Medium

This easy experiment is a cool way to show kids how heat affects air molecules, making hot air rise. They’ll need some supervision with the fire, so try this out on the playground for extra safety.

Learn more: Floating Tea Bags at Coffee Cups and Crayons

Learn how salt affects density

Plastic cups labeled "ocean," "Great Salt Lake," and "Dead Sea" (Seventh grade science)
Uplifting Mayhem

Difficulty: Easy / Materials: Medium

Explore the salinity of various bodies of water, then re-create their waters to see if you can make an egg float or sink. Experiment with other objects too.

Learn more: Saltwater Density at Uplifting Mayhem

Watch the greenhouse effect in action

Glass jar with a thermometer inside, covered with plastic wrap, next to another thermometer lying on the sidewalk
Teaching Science With Lynda

Difficulty: Easy / Materials: Medium

Climate change can be a contentious topic, so start by teaching kids about the greenhouse effect, which is easy to see and understand. Then, urge them to explore data collected by other scientists so they can learn to make informed decisions about topics like global warming.

Learn more: Greenhouse Effect at Teaching Science With Lynda

Blow bubbles to explore cell membranes

A student using a straw to blow a bubble inside another bubble in a pan of green liquid
The Trendy Science Teacher

Difficulty: Medium / Materials: Medium

Kids are never too old to enjoy bubbles, so use them to learn more about cell membranes in this fun 7th grade science activity.

Learn more: Cell Membrane Bubbles at The Trendy Science Teacher

Marvel at a density rainbow

Difficulty: Easy / Materials: Medium

We learn early on that oil floats on water, but where do other liquids fit in? Students find out when they conduct this colorful density experiment that has them layer different substances, making a rainbow.

Ride the wave (machine)

Series of sticks held together by duct tape, with clay on the ends of the sticks
Engaging Science Labs

Difficulty: Medium / Materials: Medium

Learning about wave action? Build this surprisingly easy wave machine for hands-on exploration.

Learn more: Wave Machine at Engaging Science Labs

Create a taxonomy system

Seventh grade science student sorting a pile of seeds and making notes in a notebook
Our Journey Westward

Difficulty: Medium / Materials: Medium

Students can step into Linnaeus’ shoes by creating their own system of taxonomy using a handful of different dried beans. This is a fun 7th grade science project to do in groups, so students can see the differences between each group’s system.

Learn more: Taxonomy Project at Our Journey Westward

Bake an edible cell model

Cake turned into a cell model with gummi candies and labels
Weird Unsocialized Homeschoolers

Difficulty: Medium / Materials: Medium

Sure, students could build a cell model out of clay, but cake and candy are so much more delicious! Check out the link below to see how one teacher does it.

Learn more: Edible Cell Model at Weird Unsocialized Homeschooling

Swing a glass of water

Difficulty: Medium / Materials: Medium

This classic science experiment teaches kids about centripetal force. Be forewarned: This could potentially make a bit of a mess, so consider taking this one outside.

Simulate natural selection with a lab activity

Students using tongs to lift marbles from a cup, with worksheets nearby
Teach To Serve

Difficulty: Medium / Materials: Medium

Travel to the Galápagos Islands and follow in Darwin’s footsteps as students explore finch beak adaptations in this clever natural selection lab.

Learn more: Natural Selection Lab at Teach To Serve

Participate in Project FeederWatch

Students in a classroom looking out the windows to record their bird sightings at nearby feeders
Project FeederWatch

Difficulty: Medium / Materials: Medium

Citizen science projects bring science to life for kids! One of our favorites is Project FeederWatch, where kids put out bird feeders and then count and report on their visitors. This is a great way to build a love of birding for life.

Learn more: Classroom Resources at Project FeederWatch

Experiment with basic substances to learn about chemical change

Test tubes in a rack with bleach, hydrogen peroxide, and vinegar
Super Sass and Science Class

Difficulty: Medium / Materials: Medium

If you’re introducing lab work and chemistry basics to 7th graders, this easy lab is a great way to do it. They’ll learn safety procedures and get to feel like “real” scientists as they pour, mix, swirl, and more.

Learn more: Chemical Change Lab at Super Sass and Science Class

Assemble an edible DNA model

Edible DNA model made with Twizzlers, gumdrops, and toothpicks
Hess UnAcademy

Difficulty: Medium / Materials: Medium

DNA models are always more fun when you can snack on them afterwards. Want to make this a healthier activity? Use fruits and veggies to make models instead.

Learn more: Edible DNA Model at Hess UnAcademy

Craft a food web marble maze

Marble maze with a food web theme
Student Savvy

Difficulty: Medium / Materials: Medium

Combine a STEM challenge with learning about food webs in this clever project. Kids will love the hands-on aspect, and it will really help the learning stick.

Learn more: Food Web Marble Maze at Teach Savvy

Keep the STEM learning going with these 15 Items All Middle School Math Classrooms Need.

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Find 7th grade science fair projects in every subject, plus classroom demos, experiments, and other hands-on activities to try.