Salt Water Density Experiment

Can you make a fresh egg float in water? What will happen to an egg in a saturated solution of salt water? Will an egg float or sink in salt water? What is density? What is buoyancy? There are many questions and hypotheses (predictions) to make with this easy salt water experiment, and you can learn about it all with just water, salt, and eggs! Check out all our classic science experiments for more great ideas!

SIMPLE SALT WATER DENSITY EXPERIMENT FOR KIDS!

EASY SCIENCE EXPERIMENTS FOR KIDS

Our science experiments are designed with you, the parent or teacher, in mind!  Easy to set up, quick to do, most activities will take only 15 to 30 minutes to complete, and are loads of fun!  Plus, our supplies lists usually contain only free or cheap materials you can source from home!

Get ready to add this simple salt water egg experiment to your science lesson plans this season. Let’s dig in if you want to learn whether objects can float in salt water or not.  While you’re at it, make sure to check out these other fun water experiments.

YOU MIGHT ALSO LIKE:

• Sink the Boat Challenge
• Freezing Point of Water
• Frost on a Can (not just for winter!)
• Sink or Float Experiment
• What Dissolves in Water?
• Lava Lamp With Salt

SALT WATER DENSITY EXPERIMENT

Let’s get ready to investigate! Head to the kitchen, open the pantry, and be prepared to get a little salty. And if you are curious about the rubber egg experiment in the video, click here.

YOU WILL NEED:

• 2 Tall glasses big enough to hold an egg
• Warm water
• Salt
• Spoon

SALT WATER EXPERIMENT SET UP:

STEP 1:  Start by filling one glass about 2/3 of the way full with water. Ask the kids what will happen if you carefully drop an egg into the glass of water. Now go ahead and do it!

STEP 2:  In the other glass, fill to the same height with water. Now stir in 3 tablespoons of salt. Mix well to dissolve the salt! Ask the kids what they think will happen this time and demonstrate!

TIP: Now’s a great time to talk about mixtures. By combining salt and water, you are making a mixture, an important science concept (Grab a free printable list of science words)!

A mixture is a material made up of two or more substances mixed together.  No chemical reaction takes place, and you can separate the substances in the mixture. You can have a mixture of liquids, solids, or gases.

The second egg should float due to the water’s density change!

SALT WATER DENSITY IN THE CLASSROOM

Kids can easily experiment with different objects from around the room. Small plastic items will work best with the measurements of salt and water provided.

If the item still sinks in the salt water, ask the kids what they think! Should they add more salt? Have each kid contribute an item to the experiment!

This is a great experiment to add to your ocean science lesson plans because the ocean is salty!

So many great saltwater density questions:

• Do you float better in salt water?
• What about some of the biggest mammals on earth that float easily in the ocean?
• Does the density of the saltwater play a role?

Why is the ocean salty? The simple answer is that the salt comes from the rocks on the land that has been broken down by erosion and is carries by streams to the ocean.

WHAT IS DENSITY?

Why do some objects sink while another object floats? An object sinks because it is denser or heavier than water and vice versa. Our sink and float experiment is another exciting way to look at items that might surprise you using only water.

Big items that feel light, like a ping pong ball, are less dense than smaller items that feel heavy, like a gold ring.  When added to water, objects denser than water sink, and those less dense than water float. Hollow things often float as air is less dense than water. Learn more about what is density.

You can experiment with many objects that sink and float in water, but what happens when you add salt to the water? Can you change whether the object, like the egg, still sinks?

How does salt affect the density of water?

Adding salt to the water makes the water denser.  As the salt dissolves in the water, it adds mass (more weight to the water).  This makes the water denser and allows more objects to float on the surface that would sink in fresh water. This is an example of a physical change!

Do objects float better in saltwater or freshwater?

What other items can you find to test? Most items will generally float in this salt water experiment even if they sink in freshwater. Just look at the egg!

CHECK OUT MORE SIMPLE SCIENCE IDEAS

• Sink the Boat Buoyancy Challenge
• Freezing Point of Water
• Frost on a Can (not just for winter!)
• Sink or Float Experiment
• Do Oranges Sink or Float?
• What Dissolves in Water?

Discover more fun and easy science & STEM activities right here. Click on the link or on the image below.