In this sound experiment children listen for differences as they tap on a bag of air, a bag of water, and a wooden block held up to their ears.

How much gas is released into your stomach by your favorite beverages? This project examines which beverages produce the most gas.

In this science experiment, test the pH of soil surrounding a gas station to determine if gas stations have a negative effect on the environment.

Science fair project that examines the different types of precipitation, evaluates the density of snow and calculates the ratio of snow-to-liquid.

In this fun science fair project idea learn about universal solvents and solutes and find out the solubility of several common liquid substances.

How does dishwashing liquid work? Kids discover the chemical mechanism behind cleansing power in this easy science fair project idea.

What are the effects of fertilizer on plant growth? What's the best fertilizer type (solid, liquid or powder)? Kids find out in this science fair project idea.

Check out this fun science fair project idea for middle school students to learn about the effects of temperature on the density of a gas such as air.

Science fair project that examines how yeast grows, and which conditions allow for optimal growth. What types of nutrients does yeast prefer?

The objective of this science fair project idea is to examine light refraction as it passes through liquid crystals.

This classic children's game demonstrates how sound travels through air vs. through a solid.

This project examines how temperature affects the volume of gas in balloons.

Determine whether a hot liquid cools off faster when liquid is added before or after a two minute wait.

Science fair project which examines the chemical reaction of a candle flame with various gases in order to determine the identity of the gas.

Study how liquids separate into layers by creating a liquid gradient, different density liquids separate into layers in a graduated cylinder.

The objective of this science project is to determine the relationship between carbon dioxide gas and the temperature of the atmosphere.

The objective of this science fair project idea is to determine if sound travels best through the air, water or a solid.

Science fair project that examines how temperature affects density and how density in turn affects the behavior of helium gas.

What is the coldest temperature possible? In this cool experiment, you'll calculate absolute zero by extrapolating data on the temperature and volume of gas.

Determine which kind of rock (igneous, sedimentary, metamorphic) has the greatest reservoir capacity, which is the ability to hold the most oil and natural gas.

This science fair project idea explores whether boiling and freezing water will have an effect on how much it weighs.

This project compares different liquids and the freezing, melting and boiling points of liquids.

The objective of this science project is to investigate why NASA has been using aerogel for the Stardust Project for collecting gas and dust from comets.

Kids will learn how to make a thermometer to to explore liquid density in this great science fair project. Which liquids are affected by temperature the most?

This science fair project idea examines whether adding gelatin causes a solid to have a higher melting point and/or melt slower.

Will your liquid weigh less once you remove the fat from it? Find out in this science fair project idea.

This classic children's game-connecting two cups with a string-demonstrates sound's ability to travel through air vs through a solid.

Check out this fun science fair project to make a vinegar and baking soda balloon and demonstrate how gas is created as a result of the chemical reaction.

Kids will conduct a cool limewater carbon dioxide test that can be performed with common household materials to learn about the chemistry of this common gas.

In this cool experiment, learn about the forces of resistance in a liquid and race marbles in a cylinder to find out which fluids have a high viscosity.