Science Fair Ideas for Kids: Manipulating Gases with Balloons

Of all the three basic phases of matter, gases leave the most to the imagination. Barely – and in some cases not – visible to the naked eye, gas is the most mysterious phase of matter as people have fewer ways to interact with them visibly compared to solids and liquids due to their often intangible nature.

Gases touch people’s lives constantly. They’re everywhere, expanding and contracting in kitchens, playgrounds, the sky, and even out in the vast cosmos. Gases play a huge part in keeping humanity alive, essentially allowing Earth to be inhabitable in the first place.

Through this science fair project, you will be able to play and explore the ways you can interact with this essential element of life. This experiment isn’t your run-of-the-mill and boring project too. The experiment will revolve around the usage of the fun, flexible, and stretchy materials called balloons and the ways they can help you learn about gases.


Experimenting with gases takes on a different approach to experimenting with solids or liquids. Despite the abundance of air, its unique properties can pose certain limitations and difficulties during experimentation. In order to explore and discover the dynamic properties of this mysterious phase of matter, you will have to rely on the distinct and flexible configuration of balloons.

Despite their juvenile reputation, these amusing and popular kids’ toys are popular instruments for science experiments. Balloons are prominently used to explore physics and chemistry experiments such as phases of matter and its properties and characteristics and the curious nature of air pressure.

For this particular science fair entry, you will be using balloons and their reliable features for the exploration of the many amazing properties gases have. This chemistry experiment will utilize the balloon’s flexibility to study gases’ ability to contract and expand.

You will need just a day to execute the experiment as the processes and experimental procedures are simple and possible with only simple tools and instruments. With resources and equipment readily accessible at home, online stores, or a few quick runs to pharmacies or groceries, you don’t have to spend too much for this experiment. You will only need about $20 to procure your needs and purchase the materials you need for the experiment.

Before you move forward with this project, make sure you take all safety precautions your health requires. If you have a latex allergy, it is strictly required that you stop working on this project and find something less dangerous to your health. Additionally, it is also worth noting that latex balloons are the leading choking hazard for children younger than six years old.

With all that noted, move forward (if it’s safe for you, of course) by reviewing important concepts for the science project you’re about to execute.


Gas is one of the three basic phases of matter characterized by particles that, when compared to solids and liquids, are far apart from each other. These particles move quickly and aren’t attracted to one another, making them fluid.

Since molecules in gas substances are far apart and have spaces in between, gases are much less dense than the other two phases of matter. This is why picking up an air-filled balloon with your hands is easier than carrying a water-filled balloon.

As gas molecules aren’t attracted to each other and are far apart, gases don’t have a fixed shape. Gases follow the shape of its container and even fill the tiniest nooks and crannies of the vessel it fills. Gases’ properties also don’t have a fixed volume as they continuously diffuse until they hit something that stops them. This explains why you can smell food long before you even make your way to the table. 

This independence from other gas molecules causes the particles to move around until they collide with other gas molecules or hit the wall of their containers or something else. The combined movement and motion of all these gas molecules have what is called average kinetic energy.

The spaces between gas molecules also allow them to integrate with other gases, unlike liquids, which sometimes don’t mix at all. Any combination of gases will always mix with each other. Another specific characteristic that gases have is that they can easily be compressed. The particles and molecules in gases can move together by filling the space between them, making them easy to squish down. Solids and liquids, the other phases of matter, aren’t as compressible as gases.

States of Matter

The building blocks of life or atoms make up matter. Everything around you, whether tangible or intangible is matter in some way, shape, or form. Fundamentally, three states of matter exist – solid, liquid, and gas. Using research and studies on every thing’s properties and characteristics, scientists categorized matter into these three foundational states.

Beyond the basic states of matter are the more complex phases of matter, such as plasma, bose-Einstein condensates, and others. These are the sophisticated phases of matter that describe the substances that create the universe. It is important to remember, however, that matter doesn’t stay in one phase forever. When exposed to particular circumstances and conditions, things may change states. The most common example of this is what happens to water when exposed to high and low temperatures. When exposed to the high temperatures of 100 degrees celsius, water, which is a liquid, evaporates and becomes vapor or air. On the other hand, when exposed to low temperatures of about 0 degrees celsius, or the freezing point, water freezes, becoming ice, a solid.

Solids and Liquids

The other two phases of matter yet to be discussed are the solids and the liquids. In contrast to gases, solids are dense, rigid, and incompressible due to the strong intermolecular forces between their particles. Gas particles move rapidly independent of each because of weak intermolecular forces – a sharp contrast from what solids are. The intermolecular forces between molecules in solids are so strong that they are essentially locked in place, leaving little to no room for compressibility.

Liquids, compared to the two other phases of matter, are more compressible than solids yet less compressible than gases. The particles in liquids are spread far enough that the substances in liquid form become fluid, able to take the shape of their containers. The strength of intermolecular forces between molecular forces is just between the power of solids and gases, allowing it to have a noticeable density and rigidity.


More than just an amusing kids’ toy, these colorful latex products can become fun instruments for learning and science exploration, too. Its flexibility and ability to stretch is the characteristic that allows it to be such useful tools in science projects.

Balloons are especially effective in experiments that deal with gases and their properties. From DIY experiments at home to the exploration of established theories, balloons are useful and prominent tools for experimenting with gases and other forms of matter.


Atoms make up matter – this is why they’re called the building blocks of life. When these building blocks come together, they become molecules. A molecule, according to Brittanica, is “a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.”

Simply put, molecules are the smallest unit of a substance that preserves the composition and structure of that substance. If you divide molecules even further, you will be dealing with atoms, changing a substance’s composition. This makes molecules an important concept in the field of chemistry.

Gas Expansion and Contraction

The textbook definitions of contraction and expansion are straightforward. Contraction means the process of becoming smaller, while expansion is the process of becoming larger or more extensive. However, in the context of chemistry and the study of gas properties, these processes become much more interesting.

If you’ve ever eaten bread or baked them yourself, you’d know that these products cook through exposure to heat. As bread and baked goods stay inside hot ovens, the science of expanding gases gets to work, causing the dough to rise and become the fluffy final products you know as pastries. On the other hand, gases, when exposed to colder conditions contract, causing things to become smaller.

The Experiment

It’s amazing how the things in this world interact with each other. One such interaction is between gases, a state of matter, and temperature. This science fair project aims to explore the many ways people can manipulate the properties of gases for a fun and fascinating science experiment.

One of the simplest and most efficient ways to manipulate and observe the behavior of gas molecules is through the use of a balloon. Through a simple experiment with these latex wonders, you will be able to observe the many ways gas reacts to temperature and how external forces interact with this particular phase of matter.

Through this experiment, you will be able to uncover how gases behave and how temperature affects gas molecules. The experiment revolves around the observation of what happens to a balloon when exposed to different temperature levels.

This experiment has three primary parts: the preparation, the testing phase, and the analysis. The preparation will focus on helping you gather the materials and resources needed for the project and setting up the experiment itself. The testing phase will dive deep into the methodology and research design. Finally, the analysis will guide you through data interpretation and drawing your conclusions.

The Preparation

The preparation deals with resource procurement and setting up the experiment design itself. This juncture of the project is an integral part of the experiment, allowing you to cover all the bases to ensure the success of the testing phase and, ultimately, the science fair entry. 

Material and Equipment Needed

Unlike many science fair entries nowadays, this project doesn’t require a fortune to execute. With simple household materials, standard measuring equipment, and some project-specific items from the grocery or online shops, you’ll be well on your way to getting this experiment started.

Here’s a quick list of things you need to prepare for the experiment:

  • Latex Balloons
  • A marker
  • A thermometer 
  • A cloth tape measure
  • An assistant
  • A clock
  • A lab notebook
  • Some graph paper

Now there are some things to take note of regarding these materials. It’s recommended that you procure and opt for the round balloons instead of the oblong ones, as the changes are easier to spot on the rounder varieties. Ideally, you will only need three balloons. However, for contingency purposes and in case of unplanned popping, it’s always recommended to keep extras

The thermometer needs to be able to span the temperatures you aim to test. There are special thermometers online that are able to test temperatures well below freezing temperature and well above room temperature. The cloth tape measure is also recommended to have millimeter (mm) markings or measurements.

American 3B Scientific U14295 Tube Thermometer Graduated

Buy on: Amazon / 3B Scientific

This specific thermometer model is one of the special tools available online that will help you carry out this experiment. Glass makes up the constitution of the tube thermometer and features an eyelet at the top.

The thermometer contains a red filling and provides users with a scale on a white background and a transparent storage case. This lab instrument can measure temperatures ranging from -10 degrees celsius to 110 degrees celsius. The scale division is highly precise as measurements are accurate by one-degree celsius.

Pre-Test Checks

Have you procured all the resources you need? Great. Now it’s time to ensure that the environment is optimal and set for what the experiment needs. This science fair project will need you to optimize three different areas: one at room temperature, another that’s well above room temperature, and another that’s well below room temperature.

Depending on where you are in the world, achieving room temperature should be relatively straightforward. The room has to be more or less around 20 degrees celsius. For the next room, the one that needs to be above room temperature, the goal is to leave the balloon out in a hot space, not to put it directly under sunlight. Exposure to direct sunlight will cause the gas particles to escape the balloon and deflate it as it loses gas – which will ruin the experiment. The goal is to reach the temperatures of a hot day outside or the inside of a car under the sun without air conditioning. Remember that direct sunlight and even heat lamps will ruin this project so remember not to use those. Finally, for the cold room, this can just be a freezer or a cold day outside.

Balloon Preparation

Now that you have the stage set for the experiment, it’s time to prepare the balloons. Blow up a balloon until it is fully formed but not close to popping. This experiment involves expansion and compression that might cause an overblown balloon to pop.

Mark this balloon as balloon number one and measure its circumference with the cloth tape measure. Ensure that you measure the fullest part of the balloon as you will be using this size as the standard for the sizes of the rest of the balloons. Record the measurement in millimeters (mm) for the most accurate reading possible.

Create two more balloons with identical measurements. Getting the precise sizes can be difficult. This is why it’s recommended to have an assistant around as you do your preparation. Blow each balloon up to about the same size as the first one but don’t tie them off yet. Measure the circumferences and add or let some of the air inside to mimic the measurements you have for the first balloon. If precision becomes an issue, you may opt to have a 0.5-centimeter difference between the two new balloons and the first one.

Once you have the measurements down for the second and third balloons, you’re set to get this experiment going.

Recording Instrument

It’s important to remember that every experiment is all about data. So ensure that you have an organized data gathering table to help you bring order to raw data. Here’s a design you can use for the experiment ahead:

Temperature (°C)Balloon 1 Circumference (mm)Balloon 2 Circumference (mm)Balloon 3 Circumference (mm)Average Circumference (mm)Average Circumference Cubed (mm3)

Fill out the temperature column with the temperature you record for the areas of testing and the corresponding circumferences for the balloons. Solve for the average circumference of the balloons as they change from one area to the next and as well as the average circumference cubed.

With the balloons, the areas, and your recording paraphernalia set, you’ll finally be moving on to the testing process.

Experiment Proper

Throughout this experiment, you will be measuring the size of the balloon in millimeters. Record observations and data on the table you prepared in a notebook or centralized database.

Follow the steps as written below to execute the experiment according to the design of this science fair project.

Testing at Room Temperature

Among all the testing phases, the experiment is most straightforward in the area set at room temperature.

Measure the exact room temperature of the room with the special thermometer you purchased online or at a store near you. Record the data on your table and measure the circumference of all three balloons.

Ensure that you hold the tape around the fullest part of the balloon to capture the largest available sample. Hold the measuring tape against the balloon firmly but not tight enough that the balloon would morph. Ask for assistance if needed. Record the measurements for the three balloons on the table.

Testing at Colder Temperatures

Move to the next area with all your paraphernalia and recording instruments. Depending on the area you choose for this testing, this part of the experiment may last one to three hours. Start by measuring the temperature in the cold room and take note of the measurement through the table or notebook you have ready.

If you have a huge room or freezer that can hold all three balloons at the same time, place the balloons inside and let them sit in the room or freezer for an hour. If the area of your choice is a smaller freezer, put them in one by one, letting each balloon sit in there for an hour. This means if you have three balloons, this will last for three hours.

After the balloons sit in the freezer or room for an hour each, be it all at the same time or one by one, take them out and immediately measure their circumferences the same way you did in the first room (around the fullest area and firm but not tight enough to impact the balloon’s shapes).

After each measurement, record your findings. You will have to wait at least 20 minutes at room temperature before the balloons go back to normal size. If, at this point, any balloons have popped, you may replace the balloons. However, you will have to re-do the parts you need for the subject that you lost.

Testing at Warmer Temperatures

As the balloons settle from being called and go back to their forms at room temperatures, you may place the thermometer inside the warm area you prepared for the testing.

Record the temperature right before you put the balloons into the testing area for the most recent output. Similar to the cold area testing, you may do this one at a time or all three at the same time. This time, however, you will only have to wait five to ten minutes to see the apparent changes. Remember not to use direct sunlight or heat lamps. This will cause the gas particles to escape, compromising the experiment.

Wait all ten minutes before proceeding to record your findings to ensure that the expansion takes effect. If you put all three balloons at the same time into the testing area, this will only take ten minutes. If you put the balloon in one at a time, this part of the experiment will take about 30 minutes.

Once you remove the balloons from the testing area, be it one at a time or all three at the same time, immediately record the new measurements. Use a notebook or the table you devised for the project.

Analyzing the Data

You can draw your conclusions from the various raw data yielded by this experiment. What are your observations? Did you discover anything? What questions did you have at the start that this experiment answered?

These are some of the questions you can answer by synthesizing the data you’ve gathered through the experiment. For each of the temperatures, you may calculate the average circumference and the average circumference cubed through the data available and present your findings through a table.

You may use line graphs to accurately show your findings and explore trends in the data. Is there a linear relationship between volume and circumference? How do the sizes change throughout the experiment? What are the proportions and ratios in the data that may support your hypothesis?

This science fair project is simple and fascinating. The experiment design may take some time but the result can be mystifying. Good luck with your science fair adventure!

Elena Jones

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