water density experiment with lemon

Water Density Experiments with lemon – Science project for exhibition

Water density experiments with lemons can be a fun and educational way to explore the concept of density and buoyancy.

Here are simple experiment you can try using lemons and water:

Experiment 1: Lemon Float or Sink

Materials Needed:

• A bowl or container filled with water
• Fresh lemons

Instructions:

• Fill a bowl or container with water.
• Take a fresh lemon and gently place it in the water.
• Observe whether the lemon floats or sinks in the water.

Explanation: In this experiment, you will notice that the lemon sinks in the water. This is because the density of the lemon is more than the density of water. .

Experiment 2: Lemon and Saltwater

• Take a fresh lemon and place it in the water. Observe whether it floats or sinks.
• Now, sprinkle some table salt into the water and stir to dissolve it.
• Place the same lemon back into the water with the salt.

Explanation: In this experiment, you will observe that the lemon that initially sinked in plain water now floats when placed in the saltwater. Adding salt to water increases its density, making it denser than the lemon. As a result, the lemon that originally had higher density than plain water causing it to float

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Floating Lemons and Sinking Limes

Why do lemons float in water but limes don't.

Print this Experiment

Scientists seem to be infatuated with objects that float and sink. Even non-scientists find great joy in dropping stuff in water to see if it floats or sinks. Here’s the latest float or sink challenge: Why do lemons float in water but limes sink?

Here's What You'll Need

A few lemons and limes that are roughly the same size and weight. a big lemon and a tiny lime will throw off your test results., a deep container like a large bowl.

• Fill a bowl with water and drop in the lemons. Float or sink? They should float.
• Toss the limes into the water. Float or sink? You might get a few that float but just barely. The limes in our test sank to the bottom.
• Now it’s time to figure out why. Your first guess might be the rinds of both fruits. Peel the rind off of the lemon and you’ll find that it is thick and porous, similar to the rind of an orange (that also floats in water). The lime rind is much thinner than the lemon and does not contain the same porous material.
• It’s time to test the peeled lemon and lime. Drop both in the water and you might be surprised. The lemon floats and the lime sinks! So, it’s not the rind.
• That’s as far as we’re going to take you. Keep experimenting and exploring before reading any further.

How Does It Work?

At first, our team of lemon lime researchers were certain that it had everything to do with the rind because of their experience with floating and sinking oranges. Drop an orange into water and it floats, but remove the peel from that same orange and it will sink. The unpeeled orange floats because the rind is very porous and filled with tiny pockets of air. Even though you’re removing mass when you peel the orange, the peeled orange is more dense and sinks in the water. But the lemon lime mystery is a little different.

We have to turn to the Internet for more information. According to the USDA website, a lime is 88.26% water by weight and a lemon is 87.4%. This could mean that lemons have a higher air content, but we’re still not sure.

So, our next step was to weigh the lemon and the lime. Digging through our grocery bag of lemons and limes, we found two that were very similar in size and weight. Both the lemon and the lime weighed exactly 101 grams. If you know the weight, it only makes sense to determine the volume of each fruit. Using displacement of water, we determined that the lemon had a volume of 99 mL and the lime had a volume of 90 mL. You might remember doing this in school when you learned about volume. Fill a container to the very top with water and then submerge the item (the lemon in this case). Collect and measure whatever water spills out over the edge of the container and you’ve got the volume.

So, using the density formula (D=M/V) it was easy to determine the density of each fruit.

The Lemon: Density =101g/99 mL = 1.02 g/mL

The Lime: Density = 101g/90 mL = 1.12 g/mL

Since the density of water is approximately 1 g/mL, it makes sense that the lemon in our experiment floated and the lime sank.

But we’re still a little confused as to why limes sink and lemons float. Some people have suggested that lime flesh is much more dense than lemon flesh and, as a result, it holds its juice better. People who “juice” fruits know about this phenomenon. If you want to get more juice from a lime, warm it up in the microwave briefly and then firmly roll it along the worktop before slicing it lengthways and juicing it. It makes a huge difference.

Since the density of the lemon and lime are very close to water, even very small changes in composition could mean the difference between sinking and floating.

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Science Experiments with Lemons (14+ Easy Experiments)

• October 25, 2022
• Science Experiments

Surprisingly lemons can do a lot to explore the world of science . Here is the round-up of science experiments with lemons.

Just grab a bagful of lemons and become a science magician!!

With a little guidance and simple supplies, your kids can have hours of science-based fun. Take a look!

Lemon Science Experiments

1. Make a Lemon Volcano Science Experiment for Kids

Kids love experiments that erupt! Turn the yellow pieces of summer sunshine bubble over into a gorgeous lemon volcano.

This experiment can be used to teach about chemical reactions.

A fantastic science experiment for kids is clearly explained here with full details: Make a Lemon Volcano Science Experiment for Kids

2. Lemon Battery Science Experiment for Kids

Explore the cool chemistry of creating circuits and light up the faces of children of all ages!

This super cool activity is going to be a fun science activity to try during their holiday vacation.

Check out the complete description of this lemon battery experiment here: Lemon Battery Science Experiment for Kids

3. Make invisible Ink Science Experiment

Here is another magical experiment of making invisible ink using lemons and lemon juice.

Kids love this fascinating experiment because this is so simple and easy to create invisible ink.

Adults can use this magic trick of invisible writing to get kids excited about handwriting, create art that appears on the page, and practice math facts.

Find more details of this exciting science activity here: Make invisible Ink Science Experiment

4. Science Experiment with Lemon, Salt, and Water

Have you ever wondered about watching an amazing science experiment done by your kid on his/her own?

This one can help them learn all about density and how it affects matter.

Check out here to see more details of this amazing science experiment: Science Experiment with Lemon, Salt, and Water

5. Cabbage pH Science Experiment with Lemon Juice

Create your own acid-base indicator with red cabbage. Yes. A great opportunity to teach kids about pH indicators and how a pH indicator is used to determine whether a solution is either acidic or basic.

It is a pretty cool experiment through which kids can investigate and tell the basic and acidic properties of any liquid using red cabbage.

Teach your children about acid and base chemical reactions in an easy and fun way. Click on Cabbage pH Science Experiment with Lemon Juice

6. Can you make a Lemon Sink Science Experiment?

Teach your kids how to float or make a lemon sink using the common kitchen items lemon and water.

This super cool experiment is such a great way to explore the fundamental properties of density .

You can also extend the experiment using other fruits and ask your kid to predict the results.

Learn more details of this wonderful simple science activity here: Can you make a Lemon Sink Science Experiment?

7. Inflate a balloon with lemon juice Science Activity

Kids will have a lot of fun inflating balloons on their own but this time try differently and convince your kids to inflate his/her balloon using lemon juice.

Another interesting chemistry experiment to try at home.

Do you want to inflate a balloon using lemon juice? Then click here: Inflate a balloon with lemon juice Science Activity

8. Apple Browning Experiment

Is there anything that can stop an apple from browning? This is a cool science activity that shows the process of why apples turn brown.

Get more details of the experiment here: Apple Browning Experiment

9. Lemon Foods Taste Test Science Investigation

This is something that challenges kids’ taste buds! A great opportunity to explore the scientific investigation of lemon foods in a fun way.

This is a super cool hands-on science activity to build children’s critical thinking and analysing capacity. This is best for preschoolers and kindergarten children: Lemon Foods Taste Test Science Investigation

10. Easy Inertia Science Experiment

Are you looking for fun science experiments that explain to kids about Isaac Newton’s Laws of Motion?

Here is such a fun science activity that involves a simple trick to teach kids about forces and motion .

It works as a great science fair project as well.

Find the easy inertia science experiment instructions here: Easy Inertia Science Experiment

11. Sweet and Sour Science Experiment

Do you and your kids love backyard science activities? Here is a simple and easy kid’s science experiment that uses simple ingredients from your kitchen to see if ants have a preference when it comes to sweet vs. sour.

Also, learn about the ant’s chemical signals that are used to communicate with other ants. Want to find out more about ant’s properties? Check out here: Sweet and Sour Science Experiment

12. Buoyancy Science Experiment for Kids

This classic buoyancy experiment helps kids to understand better the simple concept of why things float or sink in the water.

An amazing and easy science activity takes minutes to set up and seconds to finish.

Get ready with a few supplies and start off this cool science activity: Buoyancy Science Experiment for Kid

13. Wi-Fi Internet using Lemons Science Project

Can you create a Wi-Fi connection using lemons? Is it possible with lemons? I was surprised to watch the stunning outcome of this spectacular experiment.

Do you want to know is it possible to create a Wi-Fi connection using lemons? Here is the link you can browse to get the complete details of this science project: Wi-Fi Internet using Lemons Science Project

14. Lemonade Oobleck – The Perfect Summer Science Experiment

Another perfect summer science experiment using the perfect thing that always reminds us of summer is Lemonade!!

This is one of the kid’s favorite summer activities to do outdoors.

Creating oobleck using lemonade is the perfect way to spend a summer day.

Pre-schoolers and toddlers are perfect to engage them in this super easy summer science fun activity.

Do not miss to check out the full details of this cool science experiment here: Lemonade Oobleck – The Perfect Summer Science Experiment

Lemon chemistry is easy to understand and learn! It is amazing too.

Check out the great way to use those common kitchen hold items to explore the amazing simple science fundamental concepts more in a fun way.

To perform this citrus-based at-home or at-school simple science experiments, all your kids need are a few kitchens and household items along with a little guidance and supervision from the appropriate adults.

Grab some lemons and enjoy hands-on science activities in a fun and educational way.

Happy Experimenting!

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8 Simple Experiments to Learn About Density

Does it sink or float? And why do some liquids mix together easily (think lemon juice and water for some tasty lemonade), when others don’t mix together at all?

Here is a list of nine simple science experiments that deal with density of various objects and liquids. Enjoy!

Density Experiments – Does It Float or Sink?

It’s fun to experiment with various objects to determine if they will sink or float and then to speculate why.

The Floating Egg – Eggs naturally sink in water, but we made them float by adding one simple ingredient to the water. Want to know what it was? Find out here .

Does Clay Float or Sink – This is a great experiment that show that it’s not just an objects density that impacts if it will sink of float. The shape of the object plays an important role as well.

Bottle Diver Science Experiment  – Learn how density is used to make this scuba diver move up and down in the bottle.

Why Does the Heavier Orange Float ?  – Use this experiment to show that the weight of an old isn’t the indicator to use to determine if it will sink or float.

What causes some pop cans to float and some to sink ? – All the pop cans are the exact same shape, size and weight, but why do some of the cans float while others sink?

Density Experiments – The Density of Different Liquids

Not only is it fun to experiment with the density of various objects, but it’s also pretty amazing to experiment with the density of different liquids.

Rainbow in a Jar – This is one of our all time favorite density experiments. It takes a little pre-planning to ensure you have all the necessary liquids on hand, but the end result is quite fascinating.

Mixing Oil & Water – Will the two liquids stay mixed together? Only if you add a third ingredient into the mix! Do you know what it is?

Homemade Lava Lamp – This is another fun experiment that shows how oil & water don’t mix. Then it takes it one step further by adding one extra ingredient that causes a cool chemical reaction and results in the “lava lamp” experience.

What about you? Do you have any favorite experiments that you use to teach about density? I’m always looking for new ideas, so it you have one, leave a comment below. Thanks!

Liquid Density Experiments

Liquid Density Experiment

• 3 150 mL beakers  (or use glass jars or clear plastic cups)
• vegetable oil (you can also experiment with various types of oil, i.e. olive oil, lamp oil, baby oil)
• several small objects - raisins, paperclips, pennies, small corks, etc.
• Write down what you think will happen when you place each object into the three different liquids based on your guess of the density of liquids. Because these liquids will have different densities, there will be a density tower, or different layers, that are visible, sort of like being able to see ice cubes (frozen water) in room temperature water.
• Pour 150 mL of water into beaker #1, 150 mL of corn syrup into beaker #2, and 150 mL of vegetable oil into beaker #3. (If you are using glass jars, use 2/3 cup of liquid, which is approximately 150 mL.)
• Gently set a raisin in each beaker. Does it sink or float? Write down what happens to the raisin in each beaker.
• Take the raisins out of the beakers and try a different object, such as a paperclip or cork. Record what happens in each beaker.

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Were your predictions right? Did the raisins and other objects sink and float when you expected them to? Did they float in one liquid and sink in another? Why do you think they acted the way they did?

The less dense liquid will float on top of the more dense liquid. If one of your objects floated in the corn syrup but sank in the water, what does that tell you about the densities of water and corn syrup? Take the experiment a step further to find out more.

•   600 mL beaker (or use a large jar)
• corn syrup and/or maple syrup
• vegetable oil (you can also experiment with various types of oil, i.e. olive oil, lamp oil)
• food coloring

Which is the most dense: water, corn syrup, or vegetable oil? Which is the least dense? Based on your results from experiment #1, predict which liquid you think is the most dense and which you think is the least dense.

• Place a few drops of food coloring into the beaker of water so you will be able to tell it apart from the other liquids. (This is not necessary if you are using dark corn syrup.)
• Carefully pour 200 mL of each of the liquids into a 600 mL beaker or a large jar. Let them settle.
• What happened? Did the three liquids mix together or separate into layers? Which liquid is at the bottom of the jar? Which is at the top?

Was your prediction right? If so, the liquid you thought was the most dense should be at the bottom of the jar. The next dense will float on top of that, and the least dense will float at the very top.

Now you know how the densities of the three liquids compare to each other. If you want to find out the approximate density of each, you can calculate it using this formula: Density = Mass/Volume.

On Earth, we measure mass (how much of a substance there is) by calculating weight (how heavy it is). Weigh each liquid in grams (make sure you subtract the weight of the beaker!) and then divide that number by the volume (number of milliliters) of the liquid.

The answer is density in grams (g) per milliliter (mL).

(Your answer will be more exact if you use a  graduated cylinder  instead of a beaker to measure the volume and weigh the liquid.)

Experiment #3: Hot and Cold

• 2 150 mL beakers (or use glass jars or clear plastic cups)
• food coloring (red and blue)
• Narrow Glass or beaker

Does temperature change the density of water? Write down what you think will happen when you mix cold water and hot water.

• Fill two beakers with 150 mL (2/3 cup) of water. Put several drops of blue food coloring in one beaker, and several drops of red in the second.
• Add a handful of ice to the blue water and put it in the refrigerator for a few minutes.
• Put the red beaker in the microwave for a minute.
• Take the blue beaker out of the fridge and the red beaker out of the microwave.
• Pour some of the blue water into the 10 mL graduated cylinder or narrow glass.
• Using a pipet, slowly add red water a drop at a time and watch what happens. (This part may take a little practice—if you add the red water too fast you will force the colors to mix. Hold the pipet near the surface of the water and keep trying until you get it!)

Experiment #4: Salty or Sweet

• 3 150 mL beakers (or use glass jars or clear plastic cups)
• 10 mL graduated cylinder (or tall, narrow glass)
• stir utensil

Will adding salt make the water more dense? Will adding sugar make the water more dense? Which is more dense, sugar water or saltwater? Write down what you think will happen to the density of water if you add salt or sugar.

• Fill three beakers with 150 mL (2/3 cup) of water. Add food coloring to make blue, red, and green water.
• Add 2 teaspoons of salt to the red beaker and stir until the salt is dissolved. Add 2 teaspoons of sugar to the blue water and stir until it is dissolved.
• Try putting a raisin in each of the beakers. Does it float? Remove the raisins with a spoon.
• Pour some of the red (salty) water into the graduated cylinder. Using the pipet, slowly add the blue (sugar) water one or two drops at a time. Record which sinks to the bottom and which floats on top.
• Add the green (pure) water drop-by-drop to the other two and record what happens.

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Easy Density Experiments and Tricks for Kids

May 25, 2022 By Emma Vanstone 11 Comments

Density can be a tricky concept to grasp. Density refers to how much mass there is in a particular space. Imagine a drawer full of socks. It has a specific density. Suppose you take a sock out, the density of the drawer changes. This is because the mass of the socks has changed, but the volume of the drawer has stayed the same.

Generally, the greater the density of an object, the heavier it feels .

Solid substances are denser than their liquid and gas counterparts as the particles in a solid are much more closely packed together.

What is Density?

The density of an object is found by dividing the mass of the object by its volume.

Density Formula

Density = Mass divided by volume

The units used vary depending on the units of mass and volume used for the calculation.

If the mass is measured in kg and volume in cm³, the units for density would be in kg/cm³ .

Something else that can be confusing is mass. People often talk about weight when they mean mass and vice versa.

What is mass?

Mass is a measure of how much matter an object is made up of . The mass of an object remains constant unless you add to or remove part of it.

The weight of an object depends on gravity . Your weight would be less on the moon as there is less gravity, but your mass would stay the same.

You can do lots of very cool demonstrations to demonstrate density in a fun, hands-on way.  

Easy Density Demonstrations for Kids

These easy density demonstrations are super simple and brilliant fun ways to show kids ( and grown-ups) this tricky concept in action. There are also a couple of nifty tricks too!

How to make a Density Jar

Image taken from This IS Rocket Science

What you need to make a density column

Vegetable or sunflower oil

Food Colouring

Washing up liquid

Golden Syrup

LEGO or other small objects.

How to make a density column

First, make a very simple version using just oil and water.

• Pour some water carefully into a glass or jar.
• Very carefully add about the same volume of cooking oil on top.
• Carefully drop a couple of small objects into the mixture and observe what happens. Can you find an object to float on each layer?

What happens if you shake the jar? You should find that the oil and water mix up and then separate again.

To make a density column with more layers like the one above, you need lots of different liquids of different densities.

We used honey, golden syrup ( or corn syrup ), washing up liquid ( dish soap ), water and food colouring, and vegetable oil, in that order.

Density of Liquids

Each of the liquids has a different mass of molecules or different numbers of parts squashed into the same volume of liquid; this makes them have different densities. Therefore, one can sit on top of the other – the more dense a liquid is the heavier it is.

Objects and liquids float on liquids of a higher density and sink through liquids of lower density. The LEGO brick falls through the oil but floats on the water, while the coin sinks through both. The coin is therefore more dense than both the oil and the water. The plastic bug floating on the oil is less dense than both.

More Density Experiments

Homemade lava lamp.

Homemade Lava lamps are a fun activity demonstrating that oil and water don’t mix .

Density Trick using Salt and Water

Show your friends a science magic trick and a fantastic density demonstration . This activity uses salt to change the density of one colour of the water.

We also have a pirate themed density bottle. Pirate treasure is perfect for hiding in the layers.

Density and Floating Activities

Did you know that if you reduce the density of an object that sinks in water, it will float? We tried this with a heavy ball and used bubble wrap to make it less dense. The addition of the bubble wrap made the ball float!

You can also use the same logic to make a lemon sink or an egg float !

Science Concepts

More awesome science experiments for kids.

Don’t forget we have 100s more fun and exciting science experiments for kid s on Science Sparks.

Some of my favourites are our Fairy Tale Activities , where you can make a raft for the Billy Goats and a Zip Line for Jack and the Beanstalk. The infamous coke and mento explosion is always great fun to watch, and our water science experiments w ill keep you busy for weeks!

Wherever your interests lie, you’re sure to find something you like in our vast collection of science experiments and investigations.

Science Books from Science Sparks

I also have a couple of science books available you might like!

This IS Rocket Science

This Is Rocket Science includes 70 fun experiments for kids (and adults ) showing you how to use everyday items like bottles, cardboard, glue and tape to build excellent rocket ships, paper spinners and mobile rocket launch pads, all while learning about the scientific concepts behind space travel.

Snackable Science

Snackable Science  contains 60 edible experiments allowing kids to investigate their way around the kitchen, making magical mixtures, edible Jenga and Tetris, finding the perfect ketchup, and even creating their own super sour candy powder. It’s colourful, inviting and just brilliant fun.

Last Updated on January 29, 2024 by Emma Vanstone

Safety Notice

Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

Reader Interactions

September 07, 2012 at 7:38 pm

Oooooh! So that was it! *hunts for rainbow glass tutorial!*

September 08, 2012 at 12:05 am

Fun! We need to do this – I think my kids would love it!

September 08, 2012 at 1:38 am

Fabulous. I love the easy way you’ve explained it. Pinning to my science board 🙂

September 09, 2012 at 7:29 pm

Thank you. x

September 08, 2012 at 3:00 pm

I have treasures that would be great for this lesson.

September 09, 2012 at 7:28 pm

do let us know if you do it. x

September 09, 2012 at 8:25 am

Fantastic. Such a fascinating science experiment for kids!!! Love it.

September 10, 2012 at 6:29 pm

PS thanks for sharing on Kids Get Crafty!

September 14, 2012 at 10:26 pm

So cool!! I love it. Thank you for sharing on Sharing Saturday!!

April 21, 2013 at 8:55 pm

Another great demo for teaching density would be with pop. What you need is a fish tank full of water, a diet coke, and a regular coke. When you put the two cans in the water, the diet coke will float and the regular coke will sink. Explain to the kids that since the diet coke does not have as much mass, it is less dense so it floats.

August 03, 2021 at 7:58 am

Experiments like these are prefect for making learning fun for kids. It can spark their enthusiasm towards science. Thanks for sharing this idea!

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Salt Water Density Experiment

Can you make a fresh egg float in water? Will an egg float or sink in salt water? What is density? What is buoyancy? Answer these questions with this easy floating egg salt water experiment. Check out all our classic science experiments for more great ideas!

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

• 2 Tall glasses big enough to hold an egg

Floating Egg 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!

Science Information

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 excellent 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 salt comes from the rocks on the land that have been broken down by erosion and are carried 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? Can you change whether the object, like the egg, still sinks?

How does salt affect the density of water?

Adding salt to water densifies it. As the salt dissolves in the water, it adds mass (more weight to the water). This densifies the water 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!

Turn It Into A Floating Egg Science Fair Project

Kids can take everything they have learned about using the scientific method , stating a hypothesis, choosing variables , making observations , and analyzing and presenting data.

• Science Project Tips From A Teacher
• Science Fair Board Ideas
• Easy Science Fair Projects

To turn the floating egg experiment into a science fair project using the scientific method, start by posing a clear question. For example, “How does the salt concentration in water affect an egg’s buoyancy?” Formulate a hypothesis predicting the outcome: “The higher the salt concentration, the more likely the egg will float.”

Design the experiment by preparing several solutions with varying amounts of salt dissolved in water ( variables ), then placing an egg in each solution and observing whether it floats or sinks.

Collect and record data on the egg’s buoyancy in each solution, noting the specific salt concentrations. Analyze the results to see if they support your hypothesis. Finally, present your findings, discussing how the salt concentration affects the egg’s buoyancy and reflecting on any potential improvements or further questions during the experiment.

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?

Helpful Science Resources To Get You Started

Here are a few resources that will help you introduce science more effectively to your kiddos or students and feel confident yourself when presenting materials. You’ll find helpful free printables throughout.

• Best Science Practices (as it relates to the scientific method)
• Science Vocabulary
• 8 Science Books for Kids
• All About Scientists
• Free Science Worksheets
• Science Supplies List
• Science Tools for Kids
• Scientific Method for Kids
• Citizen Science Guide
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Printable Science Projects For Kids

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15 Comments

When I click the link to go to your blog from my email, a virus (weird website) keeps popping up. I like your blog. But you may want to check into the virus.

I think Liam’s explanation of water density is perfect – smart kid! These projects are a perfect way to *show* kids the difference, instead of just trying to explain it to them (like you said, nearly impossibly for preschoolers!)

I can see salt water being a big hit around here for experimenting! This looks so fun! Pinning for the future!

Lots of stirring but lots of interesting fun! Thanks for pinning!

Thanks Emma! He’s a smart cookie and likes to see things too understand! Not big on listening a whole bunch just yet 😉

Thanks I will look and see what I can see! Glad you like it!

Very good post. I absolutely love this site. Continue the good work!

I like this experiment but it is not about weight it is about density.

Yes, I have been meaning to update it a bit more. Thank you.

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Salt Water Density Experiment

Introduction: Salt Water Density Experiment

Step 1: Materials

Step 2: Procedure

Step 3: Additional Ideas and Resources

Extension/Modification Ideas:

• Use a triple beam balance of electronic scale to teach or practice that skill
• Use hot and cold water instead.
• Compare salt and fresh water and connect with the environment.
• Have older students teach this to younger students.
• Use other liquids to make density columns. (Water, oil, alcohol, etc.)
• Make a much larger one as part of a science night.
• Let students try making different density salt solutions and try to figure out which ones work the best and how that relates to density.

Other Density Demos:

• Egg in salt water or tap water
• Ice in water or rubbing alcohol

Attachment: I attached a Word document that is a template for a guided lab report that you feel free to modify and use. Other Ideas and Resources: These are just some ideas and alternate extensions. Some additional references will many different versions of this same idea: DENSITY: SALTWATER COLUMN LAB TEACHER PREPARATION Explains a different way to prepare solutions and some "discussion" questions as a worksheet for students Liquid Rainbow Written from the standpoint of ocean science for elementary school. Contains a lot of "teacher lingo" (e.g. key concepts, big idea, objectives, etc.) GEMS: Discovering Density book This book costs $18, but I think is where I first saw the idea for this lab. The handouts are free online in Spanish. So that might make this a cool activity to do with students learning Spanish too! Steve Spangler 7-Layer Density Column This link provides a video showing a different density experiment with different types of liquids to see how their relative densities are different. They do use the word "heavier" instead of density. He uses a slightly different way of layering. NOAA Lesson Plan: Hot, Cold, Fresh and Salty Another Earth Science/Oceans connection. This lesson plan gives ideas about having students compare hot and cold water and fresh and salty water. These are extensions that would be great to add to a simpler lesson like the one I posted.

Step 4: Real World Connection

In research labs, human blood is carefully pipetted to form a layer on top of a substance called Ficoll-Paque (made by GE). When this tube is centrifuged, the red blood cells (the most dense) go to the bottom, the Ficoll is (the next most dense), then the white blood cells, and finally the plasma (the least dense). Labs use this technique to isolate different parts of the blood. For instance, if you want to isolate the white blood cells, you can remove the plasma layer (yellow) and then gently extract the thin cloudy white layer that contains the white blood cells. Wikipedia's Ficoll-Paque Article This page describes the basics of Ficoll Ficoll-Paque PLUS Manufacturer's Description A short paragraph from the manufactures that uses the word density multiple times Ficoll-Paque Instructional Video This video shows the layering of blood on top of the Ficoll very slowly and gently and the final layers that form

Step 5: Graphic Organizer Word Document

Someone let me know the Word document does not open currently. I tried uploading another version but it also says forbidden. Message me and I can try to send it to you.

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Science At Home! Water Density Experiment

For immediate release ‐ April 09, 2020

Contact: Jessica Wackes , 919.707.9850. Images available upon request

Looking for something to keep your brain active and engaged? We’re here to help with Science at Home! Over the next few weeks, we’ll be providing you with fun science experiments you can conduct using commonly found items. You can also visit us at the Museum’s Science at Home page for additional resources.

Find a print-out version of this science experiment here!

Materials Needed:

Table salt Spoon Container of water Red and blue food color 2 clear plastic cups Large baking pan Dish towel or paper towels

Experiment Instructions:

Step 1: Place one tablespoon of salt in one of the empty cups.

Step 2: Fill one cup between 1/2 to 2/3rds full with water.

Step 3: Place several drops of red food color into the same cup and stir well.

Step 4: Fill the second plastic cup about half full with water and add a few drops of blue food color, then stir. Note: do not add salt in this cup!

Step 5: Slowly and gently, hold the spoon on the surface of the saltwater while touching the inside of the cup. Drip the blue water onto the spoon. Note: It is important to do this slowly to keep the freshwater from mixing with the saltwater.

Step 6: Continue to add the blue fresh water in this manner until you’ve reached the top of the cup.

Step 7: Step back and admire your creation!

What We’ve Learned

Freshwater is able to “float” on saltwater because saltwater is more dense: i t contains water molecules like freshwater, plus sodium and chlorine ions!

Natural Connections

Imagine you’re a captain of a ship sailing from one sea to another or moving from a large body of freshwater to the ocean.

You would need to be careful to load your cargo to reflect the different densities between these bodies of water. Failure to do so could — and has — ended up in ships capsizing!

A ship in saltwater will float higher than one in freshwater. Just like you will!

Having Fun?

We want to see! Tag @naturalsciences on social media so we can see you and your loved ones enjoying our Science at Home experiments.

Want More Experiments?

Try this one about water tension!

Try making a “rubber” egg!

For more information about our upcoming activities, conservation news and ground-breaking research, follow @NaturalSciences on  Instagram ,  Twitter  and  Facebook . Join the conversation with #visitNCMNS.

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Sink or Float: Density of Salt Water

This post may contain affiliate links.

Today I want to show you a Sink or Float Salt Water Density activity we did.  I have been wanting to do this activity for a long time and I’m glad we finally got around to it!

We experimented with the salinity of water and how it affects items sinking or floating.  We did this on the density of water based on its salt content by using fresh water, and also water with the approximate salt content in the ocean, the Great Salt Lake, the Dead Sea (bordering Israel and Jordan).

I have spent a lot of time around different bodies of salt water in my life. I grew up in Florida right by the ocean and spent many many days swimming in the ocean there.

I also had the opportunity to do a semester abroad in Israel and swam in the Dead Sea while there.

Now, I live near the Great Salt Lake and have had the opportunity to visit it with my children.  The last time we visited the Salt Lake as a family, I started thinking about trying this sink or float experiment at home with my kids.

I remember swimming in the Dead Sea. The amount of salt in the water makes your skin sting a bit when you go in.  It is nearly impossible to not float due to the high density of the water. It is a strange feeling to just float so easily in water with very little effort.  There is a similar feeling in the Salt Lake.

Different amounts of salt in the water will create different densities. Denser water will create greater buoyancy, meaning things will float more. We decided to simulate this by trying to recreate water with the same amount of salt as each of these bodies of water.

Since we had some background knowledge to this already, we knew our predictions would likely be correct. The more salt you add to water, the more dense it will be, and thus the more likely it will be that items will float in it.

How to Do the Sink or Float: Density of Salt Water Experiment

Supplies We Used:

Quart sized glass jars, wide mouth

Measuring cup and teaspoon

Various household objects

In deciding how much salt we put into the water, we based it on the percentage of salt in each body of water. I used a food scale to measure it in grams. This makes it a little easier anymore accurate.

Our control was the fresh tap water. We filled one jar with 3 cups or 720 g. of regular water and tested what would float in it. We used a few different items to compare. We put the same amount of water in each jar with varying amounts of salt percentages.

Quantity of Salt in Ocean Water:

The next jar was our ocean water. Salty ocean water is 3.5% salt. So in a jar with 3 cups or 720 g. of water that would equal 25.2 grams of salt. A teaspoon was approximately 6.5 g. of salt or 3 3/4 tsp. salt.

Quantity of Salt in the Great Salt Lake

For our third jar of water, we created water similar to the salinity of the water in the Great Salt Lake. This one is tricky because the salt levels fluctuate based on the water levels of the lake and also the location in the lake. Some areas have a higher salt content than others. I decided to go with sort of a middle, average range of 15%. That equaled 108 grams of salt which is a little more than 1/3 c of salt in 3 c. of water.

Quantity of Salt in the Dead Sea

The fourth jar of water represented the Dead Sea. The water in the Dead Sea is one of the saltiest bodies of water on the earth’s surface.  There is eight times more salt in Dead sea than ocean 36% salt!  At 36% salt that equals 259.2 grams of salt (about 3/4 c.) of salt in the 720 g. (3 c.) of water.

Saltiest Body of Water: Gaet’ale Pond

The Dead Sea is not the saltiest body of water on earth. Gaet’ale Pond in Ethiopia is 43% salt, but you can’t swim in this one!  It’s typically over 120 degrees Fahrenheit and emits toxic gases.  We did not test out the density of this one, but it is a fun fact to teach!

Will it Sink or Float?

Once the jars have both the salt and water, stir them with a spoon until the salt is dissolved as much as possible. It may get a little messy, so if you are concerned about mess, do this experiment outside, over a sink or in a small tub to catch the spills.

Now you can test out the density of each of the jars of water by seeing what things will sink or float in each jar.

Objects to Try for the Sink or Float Experiment

We tested out each of the jars of water with several common household items.  You can try anything, but here are some ideas:

• wooden blocks
• hard-boiled egg vs. a raw egg
• cherry tomatoes
• plums, apples, oranges, grapes
• highlighter pens (pencils and crayons would work well)
• ping pong balls or bouncy balls, aluminum foil rolled into a tight ball
• small toys- like lego, or army men, small toy cars
• small objects like a coin, a paper clip, dry pasta, eraser, bottle cap, buttons, coins

Try a variety of dense objects and buoyant objects so you can get a better idea of how they work.

It was really fun to make a prediction of each object and then see which guesses were correct. Sometimes we were surprised by the outcome. It was also surprising to see how much more things would float in the the saltiest water.

Our predictions that overall liquids with more salt will have a higher density and fresh water will have a low density.

Sometimes an object would sink in the fresh water, but float in all of the salt water jars, no matter the amount of salt. Sometimes we could see that the object would sit higher or lower at the top of the water.

We really enjoyed this experiment and hope you will, too!

See More Water Experiments: 25 Water Science Experiments and Activities!

Also check out this  Density Experiment for Kids where we tested the density with different liquids and substances including corn syrup, gel, and more!

Former school teacher turned homeschool mom of 4 kids. Loves creating awesome hands-on creative learning ideas to make learning engaging and memorable for all kids!

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Salt Water Density Experiment

How does food coloring react to salt & fresh water.

We love experiments that are no fuss and easy! Paired with our FREE observation lab sheet, how can you go wrong! Your students get to predict what they think will happen, make observations, and then conclude why. This experiment uses simple kitchen items to mesmerize your students. We use this Salt Water Density Experiment while investigating our Earth’s Water Unit since it is an effective at displaying the difference in density between salt and fresh water.

*Don’t miss our Floating Egg Experiment with FREE lab sheets that also investigates the difference in density between fresh and salt water. Wait… there’s more! Discover how the freezing point of salt water and fresh water differ in this experiment, “Does Fresh or Salt water freeze faster?”

As a Christian Book and Amazon affiliate, we may earn commissions from qualifying purchases. Thank you for your support. As always, we only recommend items that we truly feel will benefit your homeschooling experience. We appreciate it.

Important Terms and Facts to Introduce

Before conducting the experiment, there are a few things you should cover with your students to create a meaningful learning experience. First, spend time talking about the terms below. We discuss the meaning of salinity and density amongst other terms.

– Density is the amount of mass in a given volume.

– Salt is also called Sodium Chloride.

– Salinity  describes the amount of salt dissolved in water. Saline water is water with salt dissolved in it. 

– Solution is a type of homogeneous mixture composed of two or more substances.

– Solute is a substance dissolved in another substance, known as a solvent .

– Water’s density is 1 g/ml.

Salt Water Density Experiment Observation Sheet

The Salt Water Density Experiment Observation Sheet will guide your students through predictions, observations, and give students a place to write a conclusion. Teacher will need to guide student through the experiment and science explanation.

Gather Materials

The materials list is likely to be found within your kitchen. You will need 2 clear glasses, water, salt, and food coloring. Yes, that is it!

Salt Water Density Experiment Lab Procedures

Make predictions.

We started by filling both glasses up with about 1 1/2 cups of water. To create salt water, we added 2 tablespoons of salt to one of the glasses and stirred until completely dissolved.

Next, the students made their predictions about what they thought would happen when we added the food coloring to each glass. One of mine thought that the fresh water would be lighter in color while the salt water would be darker. Two other students predicted that the food coloring would produce bubbles in the salt water.

Make Observations

The first glass we put food coloring into was the fresh water. We only put 3 drops of blue food coloring in. There is no need to stir. This is the optimum time to just observe and then draw your observations. You will notice that the food coloring drops went to the bottom of the glass.

Next, we added the drops of food coloring to the salt water. As you can tell from the next photo, it immediately stopped when it hit the saline solution. It stayed in a layer above the salt water.

Draw Conclusions

the kids and I talk about why they think the food coloring reacted the way it did. In the end, we discuss how salt added mass to the density of the water causing it to become more dense. The density of water is a little less than 1 g/ml. So, if something sinks in water, like the food coloring, it is more dense. If something floats on a liquid, like the food coloring in the salt water glass, it is less dense. 

What I find interesting though, is that if you wait thirty minutes or so, the food coloring in both glasses will disperse. This is because the density of all of the liquids are close enough that the water molecules will eventually collide and join. Liquid molecules move and slip past each other. Pretty cool, huh?

DOWNLOAD Salt Water Density Experiment Observation Sheet

More free resources.

John 4:14  – But whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life.

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