This is a quick, easy science fair project that conveys the idea of density to preschool and early elementary children.

Sink or swim? Calculate the density of various fruits and vegetables using water and a kitchen scale.

In this science fair project, we learn how air molecules move as a result of density, convection, and air currents.

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

Science fair project which will teach you more about the foods that you eat, and learn which ones are healthier choices.

Science fair project that helps you better understand density by comparing the relative densities of cans of Coke and Diet Coke.

This science fair project idea explores how the shape of a boat affects its density and how much weight it can float.

The objective of this science fair project is to analyze the effects of salinity and temperature on water.

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

This cool science fair project teaches kids about temperature, density and buoyancy using balloons that float with normal air. No helium required!

Science fair project which simulates the global conveyor belts on a small scale, and observes the effects of wind, density and temperature on water movement.

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?

In this popcorn experiment, students can explore how two things made out of the same material can have very different appearances and densities.

In this cool experiment, learn how to find specific gravity of minerals using liquids of different densities to see which substances and items sink and float.

In this science fair project, young children discover what happens when two fluids that have different densities get together.

This science fair project idea investigates which objects float and sink in honey, water, and oil.

Before you get ready for a delicious scramble or omelet, add a bit of science to your morning routine!

Do different types of oil mix or stack? Find out in this science fair project idea!

Demonstrate how to tell the age of an egg without having to crack it open.

In this science fair project, kids start a chemical reaction that will make a balloon inflate itself!

In this science fair project, learn how a mineral streak is made and how it can help identify an unknown mineral.

In this science experiment, observe convection currents forming and learn about how heat energy moves in liquids from hot to cooler areas through convection.

Experiment with buoyancy to learn how a submarine rises and sinks in this classic science experiment.

This science fair project idea examines the reason boats are shaped and engineered.

Kids will make a beautiful rainbow in a jar and learn what enables different types of liquids to remain distinct in separate layers.

In this science fair project, you'll make a "ghost" appear in a test tube, and learn about what happens when hot water and cold water interact.

In this experiment, students find out what happens when a less-dense fluid interacts with a denser one, replicating the effect of cooler solid rock on magma.

This science fair project idea explores the different properties of matter.

In this plastic wrap science fair project, you'll learn about polymer permeability and find out which plastic wrap keeps food from dehydrating best.

This science project teaches young students about germs, bacteria, and the importance of washing their hands. Students will test what is the best way to wash.