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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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Make a Density Column

Liquid Layers Density Tower with Many Colors

Albert Martine / Getty Images 

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• B.A., Physics and Mathematics, Hastings College

When you see liquids stack on top of each other in layers, it's because they have different densities from each other and don't mix well together.

You can make a density column—also known as a density tower—with many liquid layers using common household liquids. This is an easy, fun and colorful science project that illustrates the concept of density.

Density Column Materials

You can use some or all of these liquids, depending on how many layers you want and which materials you have handy. These liquids are listed from most-dense to least-dense, so this is the order you pour them into the column:

• Corn syrup or pancake syrup
• Liquid dishwashing soap
• Water (can be colored with food coloring)
• Vegetable oil
• Rubbing alcohol (can be colored with food coloring)

Make the Density Column

Pour your heaviest liquid into the center of whatever container you are using to make your column. If you can avoid it, don't let the first liquid run down the side of the container because the first liquid is so thick that it will probably stick to the side so your column, and it won't end up as pretty.

Carefully pour the next liquid you are using down the side of the container. Another way to add the liquid is to pour it over the back of a spoon. Continue adding liquids until you have completed your density column. At this point, you can use the column as a decoration. Try to avoid bumping the container or mixing its contents.

The hardest liquids to deal with are water, vegetable oil, and rubbing alcohol. Make sure that there is an even layer of oil before you add the alcohol because if there is a break in that surface or if you pour the alcohol so that it dips below the oil layer into the water then the two liquids will mix. If you take your time, this problem can be avoided.

How the Density Tower Works

You made your column by pouring the heaviest liquid into the glass first, followed by the next-heaviest liquid, etc. The heaviest liquid has the most mass per unit volume or the highest density .

Some of the liquids don't mix because they repel each other (oil and water). Other liquids resist mixing because they are thick or viscous.

Eventually, though, some of the liquids of your column will mix together.

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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.

Liquid Density Experiment

A visual experiment to demonstrate differences in liquid unit weight.

Posted by Admin / in Matter Experiments

Different fluids have varying unit weights also known as liquid density. For example, an quart of water is lighter than a quart of pancake syrup. The same volume of both liquids have different weights. To demonstrate this concept the following experiment provides a visual way to look at 3 different liquid densities.

Materials Needed

• Vegetable oil
• Clear jar with lid
• Food coloring

EXPERIMENT STEPS

Step 1: Pour about one-quarter of the jar full of corn syrup. Stir in a few drops of the food coloring. In the photos, yellow food color was used.

Step 2: Pour in about one-quarter of the jar with vegetable oil. Observe what happens with the two fluid and note if the fluids mix together or separate.

Step 3: Pour in about one-quarter of the jar with water. Watch what happens to the water.

Step 4: Allow the water to settle and observe if any of the 3 liquids mixed together or if they stayed separated.

Step 5: Add a few drops of a different color of the food coloring. Observe what happens.

Step 6: Shake up the jar. Wait about 15 minutes and go back and look at the 3 liquids in the jar. What happened?

Science Learned

The three different fluids used in the experiment had different densities. Corn syrup has the highest density, followed by water and vegetable oil. These fluids do not mix, but instead stay separate allowing a layered look to occur. It is easy to see each type of fluid through the glass because of the colors added. In this experiment, the last color added passed through the vegetable oil and mixed with the water. The vegetable oil will not mix with any color since its molecules do not have a charge. The oil molecules are very attracted to each other, but not attracted to the molecules in the water or corn syrup.

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Air Pressure Experiment

in Matter Experiments

Simple Experiment with a good visual demonstration of changing air pressure.

Hot and Cold Water Density

Use this simple experiment to demonstrate hot and cold water density..

Water Cycle Experiment

Experiment to show all the phases of the water cycle.

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Level of Education

Post Secondary

Recommended Age

Time Required

• ~10 minutes
• ~20 minutes
• ~30 minutes

~45 minutes

• 1 day or more

Number of people

• 100 – 200 €

Supervision

Seven-Layer Density Column  WIP

Meta Description

Learning Objectives

Introduction to the concept of density.

Understanding how liquids of different densities will interact with each other.

Awareness that some liquids are immiscible.

Buoyancy The ability of an object to float in a given fluid, or rise through it if it has been fully submerged.

Density Density is defined as the mass per unit volume and is described by the equation:                                                                                          ρ=m/V where ρ represents the density, m represents the mass and V represents the volume. Density is a property of a material.

Homogeneous When a substance/substances can be mixed such that the composition of the resulting mixture is the same everywhere.

Immiscible Two substances that are not able to be mixed to form a homogeneous mixture.

Liquids A substance that flows freely and takes the shape of the container in which it has been placed.

Step 1 In each of the seven plastic cups pour a small amount of one of the different liquids, such that each cup contains a small measure of a different liquid. The amount poured into each cup depends on the size of the glass cylinder. Aim that together, the liquid volumes in the different cups will fill the cylinder.

Step 2 Add a few drops of food coloring to the colourless liquids and stir to mix in the colour.

Step 3 Empty the cup containing the honey into the glass cylinder, making sure the honey does not touch the sides of the cylinder. Always pour liquids into the cylinder gently to prevent splashes and mixing with other liquids.

Step 4 Repeat the above step for the cups with corn syrup, dish soap and water. Make sure these liquids do not do not touch the the sides of the glass cylinder.

Step 5 Add the vegetable oil to the cylinder. The liquid can be poured directly on or the food baster can be used.

Step 6 Wash the food baster using soap and use it to pour rubbing alcohol in the glass cylinder. Direct the rubbing alcohol towards the sides of the jar instead of emptying it directly into the centre of the tower, to help prevent it mixing with the other layers.

Step 7 Rinse the food baster again and use it to pour the lamp oil in a similar way to the rubbing alcohol. This makes the final liquid layer.

• Lamp oil is extremely flammable and should be handled with care.
• It is highly recommended to test the density column before the actual demonstration/experiment, as the densities of the liquids may vary from brand to brand.

A demonstration approach could be taken. In this case, prepare some labels featuring the name and density of each fluid being used in the experiment. The densities of different liquids can be found easily through a web search.Pour the liquids into the cylinder one at a time to form the different layers (as described in the ‘Method’), and after adding each layer, attach the appropriate label for that layer to the cylinder using tape or sticky tack.

An alternative approach involving experimentation can be used. Prepare cups with the different liquids as explained in the ‘Method’. Then explain the basic concepts of density as outlined in the ‘How it Works’ section, primarily that less dense liquids rise above denser liquids. Afterwards, provide the audience with the densities of half of the liquids in the cups, and encourage them to experiment in order to approximate the densities of the other liquids.

What is density? Density is defined as the mass per unit volume of a material.

Does the value of the density have something to do with the position of the layers in the glass cylinder? Yes! Higher density liquids will settle below lower density liquids.

Do water and oil mix? No. Together they form an immiscible mixture.

Do some liquids sink because they are heavy? It is more appropriate to state that denser liquid sinks below a less dense liquid. Density takes into account the volume of the liquid as well as the mass.

What happens if we don’t start with the densest material first? No matter the order in which the materials are poured into the cylinder, they will eventually settle in a density tower according to their densities, with the densest liquid at the bottom.

This demonstration explores the science of density. Density is defined as the mass per unit volume and it is a characteristic property of a substance, usually expressed in kg/m 3 . It can be considered as a measure of how much material is packed together in a set volume. A denser material has more matter packed into a given  volume than a less dense material does.  

In this experiment, there were several liquids with different densities. Since denser liquids sink below less dense liquids, the value of a liquid’s density determines the position of that liquid in the column of layers. 

Density is described by the equation:

ρ= m/ V                                                  [1]

where ρ is the symbol denoted for density, m  is the mass and V is the volume. The SI unit for density is kg/m 3 .

Density is a characteristic of a material and it is an important measure in physics. For instance, in astrophysics, density is a parameter used when observing celestial bodies. The measured density of an object in space can be compared to known densities and this gives more intuition about materials making up the objects observed.   

From equation [1], it is evident that the density changes with the mass and volume of a material. More precisely, density is directly proportional to the mass but inversely proportional to the volume. To better understand the relationship between density, mass and volume,  consider two material having different densities, such as polystyrene and lead . Lead has a density of 11340 kg/m 3 while polystyrene has a density of 11340 kg/m 3 . If we fix the mass and consider a piece of polystyrene and a piece of lead both weighing 10 grams, the piece of lead would be much smaller than the piece of polystyrene. This illustrates that density is inversely proportional to volume: the material with the larger density occupied a smaller volume when the same mass of material was considered. Similarly, if we fix the volume, for example considering two 1 cm 3 cubes of polystyrene and lead, the mass of the lead cube would be much larger than that of the polystyrene cube. This illustrates that density is directly proportional to mass: a denser material will be heavier than a less dense material when a fixed volume of each substance is considered.

The concepts of density introduced in this experiment, primarily that less dense materials rise above more dense materials, explains why hot air rises. When air is heated, the molecules gain energy and spread out further, thus occupying a greater volume. Consequently, the hot air becomes less dense and rises above neighbouring, cooler, air.

This experiment was not only an investigation into density, but also introduced the concept of immiscibility. Some liquids, such as water and oil, are said to be immiscible, meaning they cannot be mixed. The intermolecular forces of attraction within the materials determines whether they are miscible or not. If the intermolecular forces of the two liquids differ in their strength any attempt in mixing the liquids would simply fail, as the liquid having the stronger intermolecular force forms stronger bonds and thus would clump together, leaving the other liquid in a separate layer.

Application Hot air balloons can float through the atmosphere by capturing heated air. Hot air has less mass per unit volume and thus rises over cooler air, lifting the hot air balloon. See the ‘How it Works’ section for a more detailed explanation of why warm air is less dense than cooler air.

Lava lamps work in a similar way to hot air balloons. Heating of the fluid in the lava lamp causes the liquid to expand, thus increasing it’s volume and therefore decreasing its density, since the mass of fluid in the lamp is constant.  A heat source underneath the lamp creates a  temperature gradient between the top and bottom of the lamp, which causes blobs of wax to float up through the lamp.

In a completely different application to hot air balloons and lava lamps, the concept of density is used to clean up oil spills . Oil spills pose a major threat to ocean life. Oil floats on the surface of oceans as it is less dense than seawater and poses a danger to birds which swim on the water or dive into  it for food, as well as marine life living within the water. However, the fact that oil floats to the surface of water is used to clean the spilled oil.

Research The concepts of density and miscibility investigated in this experiment have been employed to research filtration techniques. The University of Brussels in Belgium investigated multiphase filtration of immiscible contaminants in soil, both theoretically and experimentally.  Multiphase filtration involves filtering a substance in a number of stages in order to remove contaminants.

• Use different brands of the same product and investigate their densities by comparing them to other liquids with known densities. This comparison can be carried out by pouring some of each test liquid onto a liquid of known density and observing whether the test liquid floats above or below the liquid of known density.

Preparation: 10 minutes

Conducting: 20 minutes

Clean Up: 10 minutes

Number of People

1 participant

Food baster or pipette

Food colouring

Glass cylinder

Light corn syrup

Rubbing alcohol

Seven plastic cups

Vegetable oil

Contributors

How Hot Air Balloons Works

How to Clean up an Oil Spill

Metals and Alloys – Densities

Miscibility of Liquids 

Polystyrene

Seven-Layer Density Column 

What causes Wind (Hot air rises) – Weather

Additional Content

Seven-Layer Density Column (Beginner)

What causes Wind (Hot air rises) – Weather  (Beginner)

Density, Specific Weight and Specific Gravity  (Intermediate)

Miscibility of Liquids  (Intermediate)

Filtration of Immiscible Liquid Contaminants in Soil and Rock Formations. (Advanced)

On density effects and large structure in turbulent mixing layers. (Advanced)

Cite this Experiment

Vella, R., & Padfield, N. (2017, November 23). Seven-Layer Density Column. Retrieved from http://steamexperiments.com/experiment/seven-layer-density-column/

First published: November 23, 2017 Last modified: November 23, 2017

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Rainbow In A Jar: Water Density Experiment

Water science is awesome! This water density experiment  with sugar uses only a few kitchen ingredients but produces an amazing science experiment for kids!    Water experiments for kids make great hands-on learning projects for kids! In this experiment, kids will explore the density of liquids, things that dissolve in water, and color mixing.

Why is Science for Kids so Important?

Kids are curious and always looking to explore, discover, check out, and experiment to discover why things do what they do, move as they move, or change as they change!

Science learning surrounds us, inside and out. Kids love checking things out with magnifying glasses , creating chemical reactions with kitchen ingredients , learning about solids that dissolve in liquids, and exploring stored energy !

Look through all our Simple Kitchen Science Activities for home or school use!

Use the Scientific Method

This rainbow water density experiment is a fantastic opportunity to use the scientific method and record your experiment using the free mini worksheet pack below.

You can read about using the scientific method here , and find more information on the independent and dependent variables used in the density experiment below!

The first step in the scientific method is asking a question and developing a hypothesis.

What do you think will happen when you add one mixture of sugar and water to another? I think the mixtures will___________. This is the first step to diving deeper into science with kiddos and making connections!

Water Density Science Fair Project

You can also easily turn your water density experiment into a fantastic presentation along with your hypothesis. Check out the resources below to get started.

• Easy Science Fair Projects
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• Science Fair Board Ideas

What is Water Density?

Density is all about the compactness of stuff in space. For this experiment, the more sugar in each glass of water, the greater the density of the water. Same space, more stuff in it! 

The denser the substance, the more likely it will sink. This is how our rainbow sugar water density tower works! Learn more about density!

Increasing the amount of sugar in the solution but keeping the water constant creates solutions with increasing densities. The more sugar you mix into the same amount of water, the higher the density of the mixture. So, density explains why the colored sugar solutions stack on top of each other inside the baster.

You could vary this water density experiment by looking at the density of different concentrations of salt dissolved in water!

YOU MAY ALSO LIKE: Viscosity Experiment For Kids

How to Make a Rainbow in a Jar

Note: You can also try a similar sugar water density activity with a Skittles rainbow in a jar .

SUPPLIES NEEDED:

• 4 Glasses or cups
• warm water and 1 cup measuring cup
• sugar and measuring teaspoon
• food coloring
• spoon and baster 

INSTRUCTIONS:

Recommended age: I suggest this experiment for upper elementary through middle school and beyond. It is not suitable for younger kids without plenty of adult assistance.

STEP 1:  Set out 6 glasses. Measure 1 cup of water into each glass. This is a great time to explain the importance of all the glasses having the same amount of water! You can read more about the scientific method for kids.

STEP 2: Add a few drops of food coloring to each glass of water. You could have your child mix the colors or help them with mixing the colors!

Note: From experience, we have found that 4 colors are the easiest to work with!

STEP 3.   Measure and add a different amount of sugar to each glass of colored water. We have since cut our experiment down to just 4 colors, but you can experiment with all of them.

• RED COLOR – 2 TBSP
• YELLOW COLOR –  4 TBSP
• GREEN COLOR – 6 TBSP
• BLUE COLOR – 8 TBSP

STEP 4.   Stir until as much of the sugar is dissolved as possible.

STEP 5.   Use your baster or pipette to create a colorful rainbow in a jar.

Tip: Have your child try two colors for an easier version!

• Squeeze the baster and put it in the red water. Release a little of the pressure to suck up some red water.
• Keep the baster squeezed, transfer it to orange, and release more to suck up some orange water.
• Continue to do this for all the colors. Leave enough pressure in the baster to get you through all six colors.

Create a Rainbow Water Density Tower

NOTE: This is probably a better experiment for elementary school or with a very patient kid. My son enjoyed trying to make the tower and simply experimenting with mixing colors.

This rainbow sugar water density tower does take a slow hand and patience.

We used a test tube from our favorite science kit! This time we found starting with the densest water {purple} worked the best.

STEP 1:   Use the baster’s measuring marks to ensure you get the same amount of each color. Add the purple to the tube.

STEP 2:   Next, add the blue, but add the blue very, very slowly. Slowly release the water along the jar’s side or glass.

STEP 3:   Continue to do the same thing,  working your way back through the colors. Slow and steady. We practiced a few times before we got a full rainbow.

You can experiment with different methods and challenge your kids to come up with a plan of action to make a rainbow in a jar.

We kept our artificial rainbow around for a couple of days. It’s so pretty in the light!

More Density Experiments to Try

You could also try a density tower with various liquids or even a homemade lava lamp to learn more about density.

Or how about a floating egg to demonstrate salt water density ?

Check out this oil and water science with a fish theme for a preschool-friendly density activity.

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More Helpful Science Resources

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32 Comments

What a super clever and pretty science experiment!

Hello! I tried this experiment with my students today with little success 🙁 The purple and blue separated perfectly, but when green was introduced, it all mixed together from there on. Any thoughts? I’m so disappointed!! Your’s is PERFECT!!!

i love this website..<3

Thank you. I’ll give this a try at home – and if I am successful I’m sure my students can do it too. 🙂

Hope you have good luck! It might take a bit of practice, but it was fun to experiment.

Practice! We had a few with only a few colors too. You have to go very slowly.

it didnt work yours is perfict

It is a tougher project and you have to be quite slow and patient!

Hello, Iam a science teacher too. Thanks for sharing this experiment with us. But there is a point that ı cannot understand.

To make in a baster, squeeze baster and put in red water. Release a little of the pressure to suck up some water. Keeping it squeezed, transfer to orange, release a little more to suck up some water.

I cant understand these sentences because my english level 🙁 Should I make the test tube oily before pouring the colors? In addition Should I use syringe to take the colored waters in order to pour them? if you can explain i will be really grateful

I found this worked well when I added 4 drops of food colouring per glass rather than 2 drop per glass which I tried first. Try adding milk after, the result is really interesting!

Ours did not work at all. Huge flop even though we followed the directions explicitly. Very frustrating. Super messy. Unsuccessful.

The key is to make sure your sugar ratios are all different so they layers separate and you do need to be slow and patient adding in the layers.

We put a cup of sugar in the purple, half a cup in the blue, quarter cup for green, two tablespoons for yellow, one for orange and none for red. Slowly dribbling each color down the side of the test tube was key to avoid mixing layers.

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what grade is this experiment for?

You can use it with a mix of ages but I think it’s best for early elementary age kids. You can add our free science journal page to it as well.

So I tried to do the experiment and I found that if you actually add the different amounts of sugar to Gatorade colors it works for better results.

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Nice Blog. very easy process to do this experiment.kids also try this at home.

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We tried this experiment with 6 colors, a turkey baster and a large glass cylinder. Epic fail. Brown sugar water was our result. We found your instructions, tried again and has great success! We used 4 colors, a pipette and shot glasses and it worked beautifully! Adding the subsequent layers VERY slowly was key. The turkey baster had a tendency to dump too much water at a time. The pipette was easier to control. Thank you!

It is a bit more challenging than most of our activities. Starting with just 2 or 3 colors might help!

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Liquid Layers – Salt Water Density Straw

Use your knowledge of density to create a colorful rainbow inside of a drinking straw.

Print this Experiment

Density can be a difficult scientific property to grasp. With that in mind, we found a way to make the science of density a colorful, fun, and (most importantly) simple experience! This project is the epitome of kitchen science. You’ll use kitchen-safe materials to make science accessible and fun. It’s quite the kid-friendly experiment when you create a colorful experience that will have young scientists understanding density in moments.

Experiment Videos

Here's What You'll Need

Food coloring, clear drinking straws, baby soda bottles and rack (optional), let's try it.

Using small cups (9 oz works great), put 1 tsp of salt into Cup #1, 2 tsp of salt into Cup #2, 3 tsp in #3, etc. up to #6. Label each cup.

Add about 9 oz of warm water to each cup. Stir the salt and water solution until all of the salt has completely dissolved.

Use the food coloring to dye the solutions in each cup a different color. If you want to make a rainbow of colors then add the following combinations of color to each cup.

Add red to cup #1, red and a yellow to Cup #2, yellow to Cup #3, yellow and blue to Cup #4, blue to Cup #5, and blue and red tablet to Cup #6.

Carefully transfer the liquids to the six tall containers like Baby Soda Bottles, and place them in order from #1-6.

Grab a clear drinking straw. Keeping both ends open, dunk the bottom end of the straw about 1 inch into the liquid of the “1 tsp” solution. Cap the top of the straw firmly with your thumb and remove the straw from the solution.

Now that you have the first solution in the straw, dip the end of the straw into the “2 tsp” solution. This time, dip the straw about 1 inch deeper than you did into the first solution. After you’ve dipped the straw, lift your thumb and replace it.

Continue the dipping process until you have all six colored solutions inside the straw. It’s a density column of salt water!

How Does It Work

Density is the measurement of how much “stuff” is packed into a measured space. Nearly every substance and material imaginable has a different density. This is especially true for the six solutions you made using salt and water. By increasing the amount of salt in the solution but keeping the amount of water constant, you create solutions that have increasing densities. The more salt that is mixed into a measured amount of water, the higher the density of the solution. As the Density Straw shows, a solution with a low density stacks on top of a solution with a higher density.

So, density explains why the solutions stack on top of each other inside the straw, but what keeps the solutions in the straw? You might expect the solutions to just fall out of the straw as you lift the straw from a solution. However, because of cohesion (similar molecules attracting each other) and adhesion (different molecules attracting each other), there is surface tension sealing the water at the bottom of the straw. The surface tension is strong enough to help hold the solutions in the straw as long as air pressure inside the straw is lower than all the air pressure outside the straw. Gravity tugs the solutions downward which creates a slight vacuum in the empty part of the straw. That lowers the air pressure inside the straw which is why you need your thumb to cap the straw. This prevents air pressure from equalizing in the straw. If you remove your thumb, the air pressure equalizes, and gravity simply moves the colored solutions out.

Take It Further

What would happen if you added the layers to the straw in reverse order? How about if you went completely out of order and added colors from #1, then #3, then #5?

Science Fair Connection

You may have mastered the Liquid Layers experiment, but now it is time to turn this experiment into a science fair project. You can make it one simply by identifying a variable (something that might change the outcome) in the experiment, then testing that variable, and correctly reporting the results.

• Try using something besides salt. Would sugar work the same?
• Instead of using salt water, try different liquids to see if you can layer them.
• Another variation you could try would be using a different size of straw. Just remember that your thumb needs to fit over the end to create a complete seal in order for this to work.

These are just a couple of ideas, but you are not limited to just them! Come up with different ideas of variables to test and give them a try. Remember, you can only change one variable at a time for each test. For example, if you are testing different liquids, make sure that all other factors in the test remain the same!

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Lesson 2.5 - The Density of Liquids

Lesson overview for teachers.

View the video below to see what you and your students will do in this lesson. 

Youtube ID: f0hoTogtFOY

Downloads:   Lesson Plan (PDF)   |   Student Activity Sheet (PDF)   |  Student Activity Sheet Answers (PDF)   |   Student Reading (PDF)   |   Teacher Background (PDF)   |   Connections to NGSS (PDF)

Students will be able to explain that the density of a liquid has to do with how heavy it is for the sample size. Students will also be able to explain that if a liquid is more dense than water, it will sink when added to water, and if it is less dense than water, it will float.

Key Concepts

• A liquid, just like a solid, has its own characteristic density.
• The density of a liquid is a measure of how heavy it is for the amount measured. If you weigh equal amounts or volumes of two different liquids, the liquid that weighs more is more dense.
• If a liquid that is less dense than water is gently added to the surface of the water, it will float on the water. If a liquid that is more dense than water is added to the surface of the water, it will sink.

Note: We are purposely using the terms “size” and “amount” instead of “volume” in this lesson about density. We are also using “heavy”, “light”, and “weight” instead of “mass”. If your students have already learned the meanings of volume and mass, you can easily use those terms to define density (Density = mass/volume), and then use those terms in this lesson. 

NGSS Alignment

• NGSS 5-PS1-3:  Make observations and measurements to identify materials based on their properties.

In the previous lesson, students learned that density has to do with how heavy an object or substance is relative to its size, and that density determines whether an object sinks or floats. Students also observed that you can compare the density of a substance to the density of water by comparing the weights of equal amounts of the substance and water using a balance.  

In this lesson: 

• As a demonstration, the teacher will compare the weight of an equal amount or volume of water and corn syrup so students can observe that corn syrup is more dense than water and sinks.
• Students will compare the weight of an equal amount or volume of water and vegetable oil and see that vegetable oil is less dense than water and floats.
• Students add corn syrup to layered oil and water and see the corn syrup sinks below both the oil and water.

Download the student activity sheet (PDF)  and distribute one per student when specified in the activity. The activity sheet will serve as the Evaluate component of the 5-E lesson plan.  

Make sure you and your students wear properly fitting safety goggles. Isopropyl “rubbing” alcohol is a flammable liquid. Keep away from heat, sparks, open flames, and hot surfaces. Isopropyl alcohol is also irritating to eyes and skin, and may cause drowsiness or dizziness if inhaled. Work with isopropyl alcohol in a well-ventilated room. Read and follow all warnings on the label.  

Clean-up and Disposal

Remind students to wash their hands after completing the activity. All common household or classroom materials can be saved or disposed of in the usual manner. 

• 2 Clear plastic cups
• Corn syrup (Karo syrup), 1 cup
• Food coloring
• Popsicle stick or plastic spoon
• Vegetable oil
• Isopropyl “rubbing” alcohol (70%)

Teacher Preparation

Pour 50 mL of corn syrup, 50 mL of water, and 50 mL of vegetable oil into three plastic cups for each group.  

Note: Corn syrup and vegetable oil can be difficult to clean out of graduated cylinders. To avoid this mess, measure and pour 50 mL of water into each of three plastic cups. Then mark the outside of each cup to indicate the level of the liquid in each cup. Pour out the water from two of the cups and dry the inside with a paper towel. Next, use those cups to measure the amount of corn syrup and vegetable oil for each group. Add 1 drop of food coloring to the corn syrup. 

Each group will need 50 mL of corn syrup, 50 mL of water, and 50 mL of vegetable oil in separate cups.  

For the demonstration, you will need 50mL of water and 50 mL of corn syrup (colored with 1 drop of food coloring) in separate cups.  

1. Do a demonstration to compare the density of corn syrup and water.

Materials for the demonstration:.

• Water in a clear plastic cup
• ¼ cup corn syrup (Karo syrup) with food coloring in a clear plastic cup
• Graduated cylinder or beaker
• Hold up two cups and tell students that you have water in one cup and the same amount or volume of corn syrup (colored blue) in the other cup.
• Place the cups on opposite ends of a balance.

Expected results

The corn syrup is heavier, which shows that it is more dense than water.  

Ask students:

• Since we weighed equal amounts and the corn syrup was heavier, is water or corn syrup more dense? Corn syrup is more dense than water.
• Predict what will happen if we pour the corn syrup into the water. Will the corn syrup float or sink when added to the water? The corn syrup should sink in the water.
• Pour the colored corn syrup into the cup containing water to see if the corn syrup floats or sinks in the water.

Expected result

It will sink. The corn syrup sinks in the water. 

Give each student an Activity Sheet (PDF) . Students will record their observations, and answer questions about the activity on the activity sheet. 

2. Have students compare equal volumes of water and vegetable oil and test whether the oil floats or sinks when added to water.

Question to investigate:  is vegetable oil more or less dense than water, materials for each group.

• 50 mL of water in cup
• 50 mL of vegetable oil in cup
• 50 mL of corn syrup in cup

• Place the cups of water and vegetable oil on opposite ends

Expected results:

The oil weighs less (is lighter) than an equal volume of water.

Ask students: 

• Which is less dense, water or vegetable oil? The vegetable oil is less dense than water because it weighs less than an equal volume of water.

• Predict what will happen when you pour the vegetable oil into the water. Will the oil sink or float? The oil will float on the water.  
• Pour the vegetable oil onto the water to see if it sinks or floats.

The oil floats in a separate layer on the water.

3. Have students pour colored corn syrup into the oil and water.

Explain to students that that they have discovered that vegetable oil is less dense than water, and that the corn syrup is more dense than water.

In one hand, hold up a cup containing vegetable oil floating on water, and in the other hand, hold up a cup containing colored corn syrup.

• Predict what will happen if you pour the corn syrup into the vegetable oil and water. The corn syrup should sink to the bottom because it is the most dense.  
• Pour the corn syrup into the cup with oil floating on water.

Expected results 

The corn syrup will sink through the oil and water resulting in three distinct layers in the cup. There will be oil on top, water in the middle, and corn syrup on the bottom. 

4. Use an animation to review and explain student observations.

Show the Animation  Density of Liquids .

Explain that to compare the density of corn syrup and water you can compare the weight of equal volumes of water and corn syrup. Since the same volume of corn syrup is heavier than water, it is more dense and sinks in water. Explain that to compare the density of oil and water you need to compare the weight of equal volumes of water and oil. Since the oil is lighter, it is less dense than water and floats on water.  

5. Do a demonstration to compare the density of water and isopropyl alcohol. 

Materials for the demonstration.

• 2 clear plastic cups
• 2 ice cubes

• Label one cup Water and the other Alcohol. Pour water and isopropyl alcohol into their labeled cups until each is about ½ full. Show students the two liquids and point out that they look very similar.
• As students watch, place an ice cube in each liquid.

An ice cube floats in water but sinks in alcohol. 

• Do you think water and isopropyl alcohol have the same density or different densities? The liquids must have different densities because the ice cube floats in one but sinks in the other. Explain that since ice floats in water, liquid water must be more dense than ice. Since ice sinks in isopropyl alcohol, alcohol must be less dense than ice. This means that water and isopropyl alcohol must have different densities and that the water is more dense than isopropyl alcohol. You could check this by comparing the mass of 50 mL of water and 50 mL of isopropyl alcohol on a balance.

The water will weigh more than the same volume of isopropyl alcohol (but not by much). 

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Fun Science: Layering Liquids Density Experiment for Kids

Layering liquid density experiment for kids.

Showing kids a liquid density experiment is fun when you use brightly colored liquids. You can find most of these liquids in your own home making this a simple kitchen science project for kids. Liquids that have more mass per unit volume, or in other words, a high density, will sink below other liquids. In this liquid density experiment, we can show how different liquids react when layered in a jar.

Look through your refrigerator and pantry for liquids of different densities. For our liquid density experiment we used the following:

• Dish Detergent
• Vegetable Oil

The liquids above are listed from the liquid with the highest density to the liquid with the least amount of density. Experiment with other liquids such as honey, syrup, rubbing alcohol, and lamp oil. Be sure to keep a close eye on young kids so they don’t touch or ingest liquids that could be harmful.

When layering liquids use a spoon, eyedropper, or straw to slowly add liquid to the previous layer. Too much force from a top layer liquid will cause the liquids to mix and the experiment won’t be as successful.

• To make a jar that looks like ours start by adding a layer of milk to the bottom of the jar. The milk we used is 1% but 2% and whole milk will work the same.
• Next add a layer of dish soap by squeezing the soap through a straw.
• Add water over the soap a little at a time. The water shouldn’t make suds in the jar when added.
• The last layer we added to our density experiment was vegetable oil. Slowly pour the oil on the water. This is also a good example of how some liquids repel each other.

How do your layers look in the jar? If you used the same ingredients as we did for our layering experiment you should have four layers in the jar making cool white, blue and golden layers. Share your liquid density experiment pictures with us by giving us a tag on Instagram !

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Layering liquids: explore density science.

Density, which is defined as mass per unit of volume is a critical scientific concept to understand and can be visually demonstrated. The mixture of oil and water is an example of two liquids that have different densities, so they remain separate when poured into a cup. This project will illustrate this phenomenon. Your child will use different liquids and see how they react with water.

What You Need:

• Tall clear cup
• Plastic cups
• Rubbing alcohol
• Turkey baster
• Blue Dawn dish soap
• Light corn syrup
• Blue food coloring
• Vegetable oil

What You Do:

• Pour some rubbing alcohol into a plastic cup and place a few drops of blue food coloring into the cup until the liquid turns dark blue. Pour some water into a second plastic cup, and place green food coloring into the cup. Pour some corn syrup into a third cup and pour orange food coloring into it.
• Pour a thin layer of honey into the tall clear cup.
• Ask your child to slowly pour the corn syrup into the tall cup.
• Next, help your child add the dish soap mixture into the middle of the tall cup.
• Add the water to the tall cup using the turkey baster.
• Next, pour the vegetable oil into the tall cup.
• Lastly, add the rubbing alcohol into the tall cup using the baster. You should now have 6 different layers of liquid.

What's Happening?

You’ll notice that the liquids don’t mix with each other! This is because they each have a different density. Corn syrup: 1.37. Water with food coloring: 1.00. Rubbing alcohol: 0.87. Dish soap: 1.03. Honey: 1.36. Vegetable Oil: 0.91. The varying densities allow you to form layers of liquids on top of each other, creating the visually stimulating display in your glass.

A Towering Experiment

Density towers are a simple and fun experiment you can do at home to demonstrate the density of liquids . Substances that are more dense create the base of the tower, while substances that are less dense seem to float in the middle and on top. You can experiment with using lots of colors to make your tower a true work of scientific art!

For this experiment you will need a clear container (as tall as you’d like), food coloring, honey, corn syrup, dish soap, water, vegetable oil, and isopropyl alcohol. Optional: use a separate container to mix your food coloring.

Start with a layer of honey. It’s the most dense substance and acts as a base for everything else. Next, add corn syrup. You should already be able to see your layers forming, because corn syrup is less dense than honey. TIP: When adding liquids pour down the sides of the container for best results. The next layer is dish soap. Try using different colors for a rainbow effect!

Now, add your water. Use the food coloring to make it whatever color you would like. Next, add vegetable oil. ( We learned about oil and water when we made lava lamps. )  Last, add the isopropyl alcohol. We added purple food coloring to make it colorful.

What’s Happening Here?

Density is the mass per unit volume; how much stuff there is in a particular space.

Think about this riddle: What weighs more, a pound of lead or a pound of feathers? Because of density we know that they weigh the same.

In our experiment, honey is the most dense substance or “heaviest” while isopropyl alcohol is the least design or “lightest.” The layers stay suspended because of the different densities of each substance.

The tower won’t stay up forever. That’s due to polarity, which learned about when we made lava lamp and crayon-resist art . The honey, corn syrup, dish soap, and water will eventually begin to mix. They are polar substances. You will notice that the vegetable oil won’t mix because it’s a non-polar substance.

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Hot and Cold Water Density Experiment

July 20, 2022 By Emma Vanstone Leave a Comment

This easy science activity demonstrates the difference in density between hot and cold water. It can be a bit messy so I would either do it outside or put the jars in a tray.

The demonstration works as cold water is more dense than hot water so the hot water sits on top of the cold.

When water is heated, water molecules move around faster, bounce off each other and move further apart. As there’s more space between the water molecules the density of warmer water is less than the same volume of cooler water.

You’ll need

Two small or medium glass jars

Small sheet of card

Food colouring

Tray – optional but advised

How to make hot and cold water density jars

Fill one of the jars with hot water and add a couple of drops of red food colouring.

Fill the second jar with cold water and add a drop of blue food colouring.

Check both jars are as full as possible.

Hot water on top of cold

Place a sheet of card over the jar filled with hot water and carefully place it on top of the jar with the cold water.

When the jars are balanced, carefully remove the card.

The two colours of water should remain separate.

Cold water on top of hot

Refill the jars and try again. This time place the cold water on top of the hot water.

The two colours of water should mix.

Density of water

Warm water is less dense than cold water so the red warm water sits on top of the cold water when the card is removed from between the jars.

If you put the hot water on the bottom the colours mix as the denser cold water drops down into the less dense hot water.

Our photo isn’t perfect as it’s hard to remove the card between the jars without some water spilling out, but do send me a photo if you get a better result.

Another density demonstration can be done using salt to increase the density of one jar of water. In the image below the blue water has the salt added.

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.

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Layering Liquids Density Experiment

Learning about density is great fun for kids. This layering liquids density experiment is fun and tasty! Give it a try.

We have done this density experiment before with our  saltwater density investigation . Today we’re changing it up a bit. Instead of using saltwater, we are using sugar water. And to make this even more fun, let’s use flavored sugar water. We’ll have a fun little drink when we’re done experimenting.

To make this an  experiment , we need to change something. Let’s change the amount of sugar in our flavored waters. We could go to the trouble of making different concentrations of sugar water, but that requires a lot of stirring and sometimes the sugar won’t dissolve as well as you hope. Let’s use pre-made flavored sugar water, aka juice {any sugary drink would work}. The greater difference in sugar concentration between the liquids, the easier it will be to layer them. {You’ll still get layering with even slight density differences – ask my Oceanography students about that lab – but the layers tend to mix, especially if your kids are doing the pouring.}

Here are the materials you need:

• Clear glasses
• Graduated cylinder (optional, but it helps use less liquid)
• grape juice (40 g of sugar)
• orange juice (22 g of sugar)
• apple juice (29 g sugar)
• white grape juice light (11 g of sugar; also sweetened with sucralose)
• water (0 g of sugar)
• Syringe (optional but it helps to layer the liquids)

Stacking Two Liquids

I showed Aiden the different liquids and told him they each contain a different amount of sugar. I asked him to pick two of them.

I said: This grape juice has more sugar than the orange juice. What do you think will happen when we pour the juices together?  (You can just use a small amount of each liquid and pour them into a tall skinny container like a graduated cylinder. You’ll use less materials this way.)

Make some predictions:

• Pour drink A onto drink B, this will happen…
• Pour drink B onto drink A, this will happen…

Make an observation: The drink with the higher amount of sugar sinks to the bottom.

We repeated this with the other drinks. Choose two liquids, predict what will happen, and observe the results.

When we added the orange juice to the apple juice, the orange juice sank. This tells us that the orange juice was more dense than the apple juice. Density isn’t just about the amount of sugar in the water. Other things dissolved in the water – maybe some pulp in the case of orange juice – will affect it. (Density is the amount of stuff [mass] per volume.)

Stacking Five Liquids

Now that we’ve established the densities of the liquids, we can layer even more liquids.

• Place the liquids in order of their density.
• Pour the most dense (highest sugar content) drink into a glass.
• Slowly pour the liquid with the next greatest density into the glass. Slowly pour the drink down the side of the glass. (Using a syringe or medicine dropper makes it easier. There will be less mixing.)
• Continue layering the liquids in order of decreasing density.

How many liquids can you stack? We managed to get five different density layers.

More Ways to Explore the Science of Liquids with Kids

Check out these liquid science activities from some of my blogger friends.

Bern from Mom to 2 Posh Lil Divas   experiments with oil and water . Allison from Learn Play Imagine  shares a walking water experiment . Megan from Coffee Cups and Crayons  asks: Does it dissolve?

Are you following Inspiration Laboratories on Facebook ? Or you can subscribe to the Inspiration Laboratories weekly newsletter. Each issue has exclusive hands-on science explorations for children, a recap of our latest activities, and special resources selected just for you!

This post was originally published on August 7, 2013.

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Density Experiment for Kids: Simple Density Tower

Science or magic? A fun density experiment for kids.

This density experiment is very neat. To kids, it appears more than a little magical but the effect is all science – no magic involved! The experiment involves forming a density tower using a combination of different liquids that form layers one atop another due to the differences in their density. Check the explanation below the experiment procedure for more about information about how and why it works.

Density Experiment for Kids: Density Tower

• Light corn syrup
• Concentrated dish soap – like Dawn
• Vodka or other alcoholic spirit
• Large jar or clear glass cylinder
• Food coloring (optional)

Hints & Tips:

• Supervise children carefully during this experiment. For children under the age of 12, it might be best for the adult to do the pouring. Use your best judgement.
• If you do not wish to use a form of alcoholic spirits, you can substitute rubbing alcohol. If you do this, the canola oil layer will go after the water layer, and the rubbing alcohol layer will be the final layer at the top of the density tower.

How to Build Your Density Tower:

1. Begin by pouring the light corn syrup into the bottom of the jar. The layer should be about an inch tall.

2. If you wish to color the light corn syrup, add a few drops of food coloring now, and stir with a fork or other object. We added a few drops of yellow food coloring to ours.

3. Next, pour the dish soap into the jar to layer on top of the oil.

For best results – each time you pour a new liquid into the jar, tip the jar to the side slightly and pour the liquid down the inside wall of the jar. Alternatively, use a turkey baster to put the liquid into the jar, again pouring the liquid down the inside wall. This will keep the pouring liquids from disturbing the liquids already in the density tower.

4. Mix a few drops of blue food coloring into some water and pour it into the jar. This will form your third layer.

5. Add a few drops of food coloring to your clear vodka or other alcoholic spirit. We used purple but you may want to use a different color if you want there to be a drastic difference between your layers. Pour the alcohol into the jar to create the fourth layer.

6. Top off the density tower with canola oil. You can color this with food coloring too if you wish.

7. Place a lid tightly on the jar, so that none of the contents will leak out.

8. Let kids have fun tipping the jar upside down and on its side, and then watch as the layers of the tower separate themselves once the jar has been placed face up again on a flat surface. Do not shake the jar, as this may cause some of the layers to combine.

How Do Density Towers Work?

An object’s density is calculated by dividing its mass (weight) by its volume (the amount of space it occupies). Liquids have density too. This experiment uses several different types of liquid to determine which is more dense. Lighter liquids are less dense than heavier liquids so they float on top of them.

For a density tower to work you also need to use the right types of liquids – those in neighbouring layers must be immiscible -that is, they do not mix. Learn more about this in our Oil and Water Experiment .

Christie Burnett is a teacher, author and mother of two. She created Childhood 101 as a place for teachers and parents to find engaging, high quality learning ideas.