simple surface tension experiments

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Surface Tension of Water Demonstration

April 17, 2019 By Emma Vanstone 3 Comments

These super simple investigations are great for demonstrating the surface tension of water .

What is surface tension?

Surface tension  is a force which causes a layer of liquid to behave like an elastic sheet or skin.

Molecules of water are more attracted to each other than other molecules, as water is a polar molecule. The positive hydrogen end of one molecule is attracted to the negative oxygen end of another water molecule. The surface water molecules only have air above them, so they are pulled down, creating surface tension.

The high surface tension of water allows insects to walk over it. Pond skaters have long, hairy legs, allowing them to spread their weight over a wide area. They press very gently on the water’s surface so as not to break through it.

In a container of water, molecules below the surface are pulled together ( or attracted to each other ) equally in all directions, but those on top are pulled together more tightly, as they don’t have water molecules above them; this draws them together to form a ‘skin’. It is this skin ( surface tension ) that stops items on the surface from sinking.

Surface Tension Holes Experiment

You’ll need.

A big bowl of water

Some ground pepper (black so you can see it) or any other ground product with colour

Washing up liquid ( dish soap )

Once the water settles, sprinkle the ground pepper over the top.

Drip some washing-up liqu id in the middle of the bowl and watch what happens.

A hole appears in the centre as the pepper moves outwards. This is your surface tension hole !

If you want to repeat the demonstration, you’ll need to wash out the bowl thoroughly to remove any traces of the dish soap ( washing up liquid ), or the effect won’t be as dramatic.

Why does this happen?

The surface tension hole is caused by the washing up liquid reducing the surface tension of the water. This allows the particles of water at the surface to spread out, starting from where the washing-up liquid was added.

More Surface Tension Experiments for Kids

Frugal Fun for Boys has an excellent surface tension investigation using a coin and different liquids !

You can use washing-up liquid to disrupt the surface tension of water to race lolly sticks .

In a magic milk experiment , the washing up liquid disrupts the surface tension of the milk, which makes food colouring spread out just like the pepper and water.

Another surface tension experiment is where you make a shape on the surface of the water with cocktail sticks and drop some washing-up liquid in the centre to force the sticks apart.

Watch how water behaves on the space station with this NASA video.

Try filling a bowl half full with water and carefully placing a paperclip on the top, so it floats. Mix a little washing-up liquid in a cup with water and gently pour it into the bowl; the paper clip will sink as the water can no longer support the weight of the paper clip after the washing-up liquid disrupts the surface tension of the water.

Science concepts

Surface tension

Last Updated on July 8, 2023 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

October 16, 2011 at 3:00 pm

Great activity, I am going to try it with my daughter! I love how you call it “washing up liquid” – I call it that too. 🙂

October 16, 2011 at 9:26 pm

Thanks, glad you like it!

October 21, 2011 at 6:01 pm

So many great ideas come form this blog! Thank you for linking up to the The Sunday Showcase

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7 Surface Tension Experiments To Try With Kids

• November 2, 2022
• Science Experiments

Here is a list of easy and fun surface tension experiments for kids. These surface tension experiments with water can help kids learn about static water and the forces within it.

Do you love the 4th of July milk fireworks?

What if you can create them using milk?

Have you noticed crazy little balls in your coffee mug while stirring it?

Well, it’s possible to recreate them! There are lots of other factors to know. So, let’s have a look at the seven science experiments that will help to understand physics in a better way while having fun at home.

1. Milk Fireworks        

This is an easy science activity that needs only a few raw materials and can prove to be a great boredom buster. 

Raw materials 

• A dish 
• Food coloring agents 
• Liquid dish soap

Required Steps 

• Take the dish and pour some milk into it.
• Now drop a few drops of coloring agents in the middle.
• Now take an earbud soaked in liquid dish soap and dip it into the middle with food coloring agents. 
• The colors get scattered in all directions like fireworks! 

Observation

Experiment Observing that adding little soap to the milk weakens its surface tension by pushing the milk molecules with its hydrophobic ends. Also, the food coloring agents are pushed along with them, and end up having a spectacular sight of  fireworks on liquids !

Note: You can conduct this experiment with milk at different temperatures such as warm and very cold to see whether this will make any difference to the behavior of the milk molecules.

2. Water BBS

This experiment demonstrates how crazy little balls notice in the coffee mug while stirring it.

• One cup of coffee
• One coffee stirrer
• Few drops of liquid soap

Required steps

• Take the coffee mug and stir it with the stirrer
• Maybe nothing will happen, and then mix a few drops of liquid soap

In this experiment, notice some little balls in the coffee mug, which are nothing but anti-bubbles. These bubbles are formed when a liquid is dropped turbulently into the same or another liquid.

These are thin films of gas enclosing a sphere of liquid that can appear and then get fully submerged in the liquid.

Unlike ordinary air bubbles, these anti-bubbles do not rise quickly on the top. Patient to see them as they are quite mesmerising.

3. Soap Boat

This science activity video on a  soap boat experiment  is all about the surface tension of water and the impact of soap on water.

• 1 dish containing water
• 1 little boat with a notch out of a card
• A few cotton buds
• Liquid soap
• Take the dish and place the little paper boat on the surface of the water
• Now, soak the cotton bud in liquid soap and touch its tip into the water to power your paper boat

In this experiment, the boat will start moving swiftly! Now, this happens when you touch the soap on the surface of the water. Soap weakens its surface tension and creates enough force to push the lightweight paper boat. Interesting to notice it!

4. Floating Card

• 1 open jar with a mesh screen on its mouth  
• 1 card 
• 1 jug of water
• Take the open jar with the mesh screen and pour water into it from the jug
• Now, take the card and place it gently in the mouth of the jar
• Invert the jar, and you will see that it will uphold the card!
• Next, gently remove your hand from the card
• Slid out the card from beneath the jar
• The jar will hold up the water mysteriously!

 Observation

Observations help to notice the  mysterious water suspension.  So, the science behind this  floating water trick  is nothing but the surface tension across the screen, which holds up the water.

There is also a role of cohesion to play in this science activity. It is the cohesion that causes surface tension. Here, water molecules remain joined together between each tiny opening of the screen mesh and form a thin invisible membrane that is strong enough to hold the water when the jar is inverted.

You can even stick some needles inside the jar! Interestingly, the surface tension will successfully prevent the water from falling in that case too! 

You can use this experiment as a magic trick before your friends and can, later on, explain to them the science behind the water suspension.

5. Suddenly sinking paper clips

This science activity video on  paper clip floating  and sinking is again about the surface tension of water.

• 1 glass containing water
• 1 paper clip
• 1 piece of tissue paper
• A small quantity of liquid soap
• Take the paper clip and place it on top of the water surface of the glass
• Try to balance it on the water surface
• If it sinks, take it out from the glass
• Now, place the piece of small tissue paper on the water surface and then put the paper clip on it
• Next, gently remove the tissue paper from beneath the paper clip as it will start floating on the water surface
• Now take the Q-tip and soak it in liquid soap and touch its tip into the water
• The paper clip will again sink at the bottom! 

Now, wondering why is the  paper clip floating on water soap?  Well, the reason is again the humble surface tension! 

In the second step, then try to make the paper clip float on the water surface, it sinks because the metal with which the clip is made is denser than the water. 

However, when placing it on a piece of floating tissue paper, it does not sink because now the surface tension of the water is supporting it.

Again, when you touch the water with soap, this surface tension gets reduced. So, the clip sinks like a brick into the glass. 

Also, let’s experiment with this interesting activity with different lightweight objects to see whether the same thing is happening again. 

6. Penny Dropper

Have you ever wondered  how many drops of water can fit on a penny ?

Well, this super fun science activity will give all the answers. 

• 1 plastic dropper 
• Take the penny and place it on a flat surface
• Now take the dropper, fill it with water, and put a drop of water at the center of your penny
• Keep on adding water drops to the penny and count
• A dome shape made up of water drops will form on the penny 

The experiment makes us observe that a penny can hold several water drops before it eventually starts spilling over the coin. Here, it is the surface tension of water that prevents the water molecules from falling apart. So, the water molecules remain together and form a dome shape. Even Experimenting with other liquids such as saltwater, milk, and soapy water to figure out whether they yield the same result or not.

7. Leidenfrost Effect        

Have you ever heard about the  Leindenfrost effect ?

Well, it is a phenomenon where liquids, instead of getting evaporated, glided on the surface of a pan. This happens when the pan is heated beyond the boiling point of that liquid. 

This effect was named after the German doctor Johann Gottlob Leidenfrost (1715-1794), who described this effect. 

However, to do this exciting science experiment, you will need adult supervision as this involves heat hazards! 

• 1 empty pan
• One dropper
• Take the empty pan and put it on a stove.
• Next, add some water droplets into the pan one by one with the help of the dropper, and the water droplets will quickly evaporate. 
• Keep on adding the water droplets but now increase your speed. 
• Water droplets will now not evaporate. They will instead make small spheres gliding on the hot surface of the pan.

The observation makes us wonder how  does water dance on a hot pan . See, when heating the pan more than the boiling point of water, which is 100-degree Celsius, water drops vaporize quickly that it forms a layer of steam that insulates the rest of the water droplets are added from the hot surface of the pan. As a result, you end up watching the dancing water droplets. 

All the above activities can be done at home to develop a better understanding of some key concepts of physics. 

Dianna Cowern, also called physics girl presented a video of seven experiments or science tricks that offer surface tension, anti-bubble, cohesion, and lienenforst effect.

Courtesy: Physics Girl

https://www.youtube.com/watch?v=WsksFbFZeeU&feature=emb_logo

https://www.antibubble.org/

https://www.stevespanglerscience.com/lab/experiments/water-screen/

https://msdlt.instructure.com/courses/108/files/2571/download?wrap=1

https://www.rookieparenting.com/how-many-drops-of-water-can-you-put-on-a-penny/

https://www.sociologygroup.com/water-drops-dance-hot-plate/

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Surface Tension Experiments

Science can be absolutely hands-on and engaging for kids. Learn about the surface tension of water with our simple definition below. Plus, check out these fun surface tension experiments to try at home or in the classroom. As always, you’ll find fantastic and easy to do science experiments at the tip of your fingers.

What Is Surface Tension Of Water?

Surface tension exists on the surface of water because water molecules like to stick to each other. This force is so strong that it can help things sit on top of the water instead of sinking into it. Like our pepper and soap experiment below.

It is the high surface tension of water that allows a paper clip, with much higher density, to float on water. It also causes drops of rain to stick to your windows, and is why bubbles are round. Surface tension of water also helps propels water-striding insects on the surface of ponds.

Also learn about capillary action !

Scientist, Agnes Pockels discovered the science of surface tension of fluids simply doing the dishes in her own kitchen.

Despite her lack of formal training, Pockels was able to measure the surface tension of water by designing an apparatus known as the Pockels trough. This was a key instrument in the new discipline of surface science. In 1891, Pockels published her first paper, “Surface Tension,” on her measurements in the journal Nature.

Easy Surface Tension Experiments

Here are some fun ways to demonstrate the surface tension of water. Plus, all you need is a handful of common household supplies. Let’s play with science today!

Bubble Snakes

Find out how you can blow up a gigantic bubble snake all with the help of surface tension.

Drops Of Water On A Penny

A fun science activity with pennies and water. How many drops of water do you think you can get on a penny? The results might surprise you and all because of surface tension!

Floating Paperclip Experiment

How do you make a paperclip float on water? Learn about surface tension of water, with a few simple supplies.

Magic Pepper and Soap Experiment

Sprinkle some pepper in water and make it dance across the surface. Learn about the surface tension of water when you try this fun pepper and soap experiment with kids.

Magic Milk Experiment

Try this color-changing milk and soap experiment. Similar to water, the dish soap breaks the surface tension of the milk, allowing the food coloring to spread out.

Geometric Bubbles

Explore surface tension while you blow bubbles! Make your own homemade bubble solution too!

Paper Clips In A Glass

How many paper clips fit in a glass of water? It’s all to do with surface tension!

Soap Powered Boat Experiment

Explore surface tension up close as kids observe firsthand how soap influences the movement of a small boat on the water’s surface.

Bonus Activity: Water Drop Painting

Not an experiment as such but still a fun activity that combines science and art. Paint with water drops using the principle of surface tension of water.

Free Printable Science Project Worksheets!

What is the scientific method?

The scientific method is a process or method of research. A problem is identified, information about the problem is gathered, a hypothesis or question is formulated from the information, and the hypothesis is put to test with an experiment to prove or disprove its validity. Sounds heavy…

What in the world does that mean?!? The scientific method should simply be used as a guide to help lead the process.

You don’t need to try and solve the world’s biggest science questions! The scientific method is all about studying and learning things right around you.

As kids develop practices that involve creating, gathering data evaluating, analyzing, and communicating, they can apply these critical thinking skills to any situation. To learn more about the scientific method and how to use it, click here.

Even though the scientific method feels like it is just for big kids…

This method can be used with kids of all ages! Have a casual conversation with younger kiddos or do a more formal notebook entry with older kiddos! Learn more about using the scientific method with kids.

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
• All About Scientists
• Free Science Worksheets
• DIY Science Kits
• Science Tools for Kids
• Scientific Method for Kids
• Citizen Science Guide
• Join us in the Club

Printable Science Projects For Kids

If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!

• 90+ classic science activities  with journal pages, supply lists, set up and process, and science information.  NEW! Activity-specific observation pages!
• Best science practices posters  and our original science method process folders for extra alternatives!
• Be a Collector activities pack  introduces kids to the world of making collections through the eyes of a scientist. What will they collect first?
• Know the Words Science vocabulary pack  includes flashcards, crosswords, and word searches that illuminate keywords in the experiments!
• My science journal writing prompts  explore what it means to be a scientist!!
• Bonus STEAM Project Pack:  Art meets science with doable projects!
• Bonus Quick Grab Packs for Biology, Earth Science, Chemistry, and Physics

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~ projects to try now ~.

Surface Tension - Definition and Experiments

Understand Surface Tension in Physics

• Physics Laws, Concepts, and Principles
• Quantum Physics
• Important Physicists
• Thermodynamics
• Cosmology & Astrophysics
• Weather & Climate

Causes of Surface Tension

Examples of surface tension, anatomy of a soap bubble, pressure inside a soap bubble, pressure in a liquid drop, contact angle, capillarity, quarters in a full glass of water, floating needle, put out candle with a soap bubble, motorized paper fish.

• M.S., Mathematics Education, Indiana University
• B.A., Physics, Wabash College

Surface tension is a phenomenon in which the surface of a liquid, where the liquid is in contact with a gas, acts as a thin elastic sheet. This term is typically used only when the liquid surface is in contact with gas (such as the air). If the surface is between two liquids (such as water and oil), it is called "interface tension."

Various intermolecular forces, such as Van der Waals forces, draw the liquid particles together. Along the surface, the particles are pulled toward the rest of the liquid, as shown in the picture to the right.

Surface tension (denoted with the Greek variable gamma ) is defined as the ratio of the surface force F to the length d along which the force acts:

gamma = F / d

Units of Surface Tension

Surface tension is measured in SI units of N/m (newton per meter), although the more common unit is the cgs unit dyn/cm (dyne per centimeter).

In order to consider the thermodynamics of the situation, it is sometimes useful to consider it in terms of work per unit area. The SI unit, in that case, is the J/m 2 (joules per meter squared). The cgs unit is erg/cm 2 .

These forces bind the surface particles together. Though this binding is weak - it's pretty easy to break the surface of a liquid after all - it does manifest in many ways.

Drops of water. When using a water dropper, the water does not flow in a continuous stream, but rather in a series of drops. The shape of the drops is caused by the surface tension of the water. The only reason the drop of water isn't completely spherical is that the force of gravity pulling down on it. In the absence of gravity, the drop would minimize the surface area in order to minimize tension, which would result in a perfectly spherical shape.

Insects walking on water. Several insects are able to walk on water, such as the water strider. Their legs are formed to distribute their weight, causing the surface of the liquid to become depressed, minimizing the potential energy to create a balance of forces so that the strider can move across the surface of the water without breaking through the surface. This is similar in concept to wearing snowshoes to walk across deep snowdrifts without your feet sinking.

Needle (or paper clip) floating on water. Even though the density of these objects is greater than water, the surface tension along the depression is enough to counteract the force of gravity pulling down on the metal object. Click on the picture to the right, then click "Next," to view a force diagram of this situation or try out the Floating Needle trick for yourself.

When you blow a soap bubble, you are creating a pressurized bubble of air which is contained within a thin, elastic surface of liquid. Most liquids cannot maintain a stable surface tension to create a bubble, which is why soap is generally used in the process ... it stabilizes the surface tension through something called the Marangoni effect.

When the bubble is blown, the surface film tends to contract. This causes the pressure inside the bubble to increase. The size of the bubble stabilizes at a size where the gas inside the bubble won't contract any further, at least without popping the bubble.

In fact, there are two liquid-gas interfaces on a soap bubble - the one on the inside of the bubble and the one on the outside of the bubble. In between the two surfaces is a thin film of liquid.

The spherical shape of a soap bubble is caused by the minimization of the surface area - for a given volume, a sphere is always the form which has the least surface area.

To consider the pressure inside the soap bubble, we consider the radius R of the bubble and also the surface tension, gamma , of the liquid (soap in this case - about 25 dyn/cm).

We begin by assuming no external pressure (which is, of course, not true, but we'll take care of that in a bit). You then consider a cross-section through the center of the bubble.

Along this cross section, ignoring the very slight difference in inner and outer radius, we know the circumference will be 2 pi R . Each inner and outer surface will have a pressure of gamma along the entire length, so the total. The total force from the surface tension (from both the inner and outer film) is, therefore, 2 gamma (2 pi R ).

Inside the bubble, however, we have a pressure p which is acting over the entire cross-section pi R 2 , resulting in a total force of p ( pi R 2 ).

Since the bubble is stable, the sum of these forces must be zero so we get:

2 gamma (2 pi R ) = p ( pi R 2 ) or p = 4 gamma / R

Obviously, this was a simplified analysis where the pressure outside the bubble was 0, but this is easily expanded to obtain the difference between the interior pressure p and the exterior pressure p e :

p - p e = 4 gamma / R

Analyzing a drop of liquid, as opposed to a soap bubble , is simpler. Instead of two surfaces, there is only the exterior surface to consider, so a factor of 2 drops out of the earlier equation (remember where we doubled the surface tension to account for two surfaces?) to yield:

p - p e = 2 gamma / R

Surface tension occurs during a gas-liquid interface, but if that interface comes in contact with a solid surface - such as the walls of a container - the interface usually curves up or down near that surface. Such a concave or convex surface shape is known as a meniscus

The contact angle, theta , is determined as shown in the picture to the right.

The contact angle can be used to determine a relationship between the liquid-solid surface tension and the liquid-gas surface tension, as follows:

gamma ls = - gamma lg cos theta

• gamma ls is the liquid-solid surface tension
• gamma lg is the liquid-gas surface tension
• theta is the contact angle

One thing to consider in this equation is that in cases where the meniscus is convex (i.e. the contact angle is greater than 90 degrees), the cosine component of this equation will be negative which means that the liquid-solid surface tension will be positive.

If, on the other hand, the meniscus is concave (i.e. dips down, so the contact angle is less than 90 degrees), then the cos theta term is positive, in which case the relationship would result in a negative liquid-solid surface tension!

What this means, essentially, is that the liquid is adhering to the walls of the container and is working to maximize the area in contact with solid surface, so as to minimize the overall potential energy.

Another effect related to water in vertical tubes is the property of capillarity, in which the surface of liquid becomes elevated or depressed within the tube in relation to the surrounding liquid. This, too, is related to the contact angle observed.

If you have a liquid in a container, and place a narrow tube (or capillary ) of radius r into the container, the vertical displacement y that will take place within the capillary is given by the following equation:

y = (2 gamma lg cos theta ) / ( dgr )

• y is the vertical displacement (up if positive, down if negative)
• d is the density of the liquid
• g is the acceleration of gravity
• r is the radius of the capillary

NOTE: Once again, if theta is greater than 90 degrees (a convex meniscus), resulting in a negative liquid-solid surface tension, the liquid level will go down compared to the surrounding level, as opposed to rising in relation to it.

Capillarity manifests in many ways in the everyday world. Paper towels absorb through capillarity. When burning a candle, the melted wax rises up the wick due to capillarity. In biology, though blood is pumped throughout the body, it is this process which distributes blood in the smallest blood vessels which are called, appropriately, capillaries .

Needed materials:

• 10 to 12 Quarters
• glass full of water

Slowly, and with a steady hand, bring the quarters one at a time to the center of the glass. Place the narrow edge of the quarter in the water and let go. (This minimizes disruption to the surface, and avoids forming unnecessary waves that can cause overflow.)

As you continue with more quarters, you will be astonished how convex the water becomes on top of the glass without overflowing!

Possible Variant: Perform this experiment with identical glasses, but use different types of coins in each glass. Use the results of how many can go in to determine a ratio of the volumes of different coins.

• fork (variant 1)
• piece of tissue paper (variant 2)
• sewing needle

Place the needle on the fork, gently lowering it into the glass of water. Carefully pull the fork out, and it is possible to leave the needle floating on the surface of the water.

This trick requires a real steady hand and some practice, because you must remove the fork in such a way that portions of the needle do not get wet ... or the needle will sink. You can rub the needle between your fingers beforehand to "oil" it increase your success chances.

Variant 2 Trick

Place the sewing needle on a small piece of tissue paper (large enough to hold the needle). The needle is placed on the tissue paper. The tissue paper will become soaked with water and sink to the bottom of the glass, leaving the needle floating on the surface.

• lit candle ( NOTE: Do not play with matches without parental approval and supervision!)
• detergent or soap-bubble solution

Place your thumb over the small end of the funnel. Carefully bring it toward the candle. Remove your thumb, and the surface tension of the soap bubble will cause it to contract, forcing air out through the funnel. The air forced out by the bubble should be enough to put out the candle.

For a somewhat related experiment, see the Rocket Balloon.

• piece of paper
• vegetable oil or liquid dishwasher detergent
• a large bowl or loaf cake pan full of water

Once you have your Paper Fish pattern cut out, place it on the water container so it floats on the surface. Put a drop of the oil or detergent in the hole in the middle of the fish.

The detergent or oil will cause the surface tension in that hole to drop. This will cause the fish to propel forward, leaving a trail of the oil as it moves across the water, not stopping until the oil has lowered the surface tension of the entire bowl.

The table below demonstrates values of surface tension obtained for different liquids at various temperatures.

Experimental Surface Tension Values

Edited by Anne Marie Helmenstine, Ph.D.

• Examples of Chemical Reactions in Everyday Life
• How to Perform the Pepper and Water Science Magic Trick
• Cohesion Definition in Chemistry
• Surface Tension Definition and Causes
• How to Read a Meniscus in Chemistry
• The Different Meanings of Meniscus in Science
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• What Is a Surfactant?
• How Superheating Works - Water in a Microwave
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• Cool Things to Do With Dry Ice
• What Are the Bubbles in Boiling Water?
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• Emulsion Definition and Examples
• Floating Spinach Disks Photosynthesis Demonstration

Surface Tension Science Experiment for Kids

• Science Experiments

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Teach kids about science with a simple science experiment that will leave kids curious and ready to experiment. This surface tension experiment uses a couple simple materials to help teach  surface tension for kids in only 5 minutes! Use this  surface tension experiments with kindergarten, pre-k, first grade, 2nd grade, 3rd grade, 4th grade, 5th grade, and 6th grade students. I love using simple activities to help kids start to understand bigger principles like this easy science lesson on surface tensions.

Surface tension for kids

Try this quick  surface tensions experiment to teach children about  surface tension for kids . Using just jars of water, cotton balls, and liquid dish soap you can make the scientific principle of tension easy for kids to understand. Use this  surface tension experiments for kids of all ages from preschoolers, kindergartners, grade 1, grade 2, grade 3, grade 4, grade 5, and grade 6 students. I love using hands-on exploration to make learning fun and show that science doesn’t have to be complicated; science is fun!

What is surface tension

Water molecules like to stick together. On the surface where the water meets the air, water molecules cling even more tightly to each other. This is called  surface tension . To lower the surface tension of water, you can heat it up or add soap or detergent. These two things cause the attraction between the water molecules to lessen. In the case of the cotton balls, the structure of a cotton ball is lots of wound cotton fibers with tiny pockets of air between then. When the cotton ball first hits the cold water, it is lighter than the water and floats. Then, water starts to slowly creep into those air pockets and replace the air. This causes the cotton ball to eventually sink.

What is surface tension for kids

When the cotton ball hit the glass of hot water, the same thing happens as in the cold water, but at a faster rate. This is caused because the surface tension of the water is lower in this glass. This makes the water move into the cotton balls much faster. Try this experiment again by adding a couple drops of dish detergent to a glass of cold water. Compare the rate the cotton ball sinks to the plain cold water and/or the hot water. What are the results and why? You can, also, try the varying temperatures of water or use different types and amounts of soap.

Surface tension experiments

To complete this easy science experiment for kids all you need are a few simple materials you already have on hand:

• 2 or 3 glass jars (drinking glasses)
• 3+ cotton balls
• liquid dish detergent

Surface tension experiment

To try this surface tension project , fill one of the jars with cold water and another with hot water. Drop a cotton ball into each of the glasses at the same time. Notice what happens to the cotton balls. Do they sink or float? Does one sink faster than the other? Why? Here’s a hint: What you are observing is a result of the surface tension of water.

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Beth Gorden

Beth Gorden is the creative multi-tasking creator of 123 Homeschool 4 Me. As a busy homeschooling mother of six, she strives to create hands-on learning activities and worksheets that kids will love to make learning FUN! She has created over 1 million pages of printables to help teach kids ABCs, science, English grammar, history, math, and so much more! Beth is also the creator of 2 additional sites with even more educational activities and FREE printables – www.kindergartenworksheetsandgames.com and www.preschoolplayandlearn.com. Beth studied at the University of Northwestern where she got a double major to make her effective at teaching children while making education FUN!

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Surface Tension Experiments for Kids

Activities » Science » Surface Tension Experiments for Kids

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Are you looking for simple, yet fascinating science experiments that your kids can do at home? Why not explore the topic of surface tension with some fun activities and experiments? Surface tension is an interesting phenomenon that captures the imagination of even young children.

With just a few materials, they will be able to conduct hands-on experiments to observe and understand surface tension in action.

In this post, we’ll talk about what surface tension is, provide examples of relevant everyday objects as well, and explain four engaging experiments you and your kids or students can try out today! Let’s get started!

As you can probably guess from all my science-related posts lately, my sons are a bit, shall we say, obsessed with science experiments right now. For example, we love the dancing milk experiment and love doing experiments with try ice !

What are 5 examples of surface tension?

Surface tension is the property of a liquid that allows it to resist external forces that could increase its surface area. Here are five examples of surface tension in action:

• Water Striders: Water striders are insects that can walk on the surface of water due to the surface tension of water. Their legs do not break through the surface because of the cohesive forces between water molecules.
• Capillary Action: Surface tension is responsible for capillary action, where liquids can rise or fall in narrow tubes or porous materials against the force of gravity. This phenomenon is seen in plants’ ability to draw water from the soil into their roots.
• Droplets Forming on Leaves: When you see water droplets forming on the surface of leaves or other hydrophobic (water-repellent) surfaces, it’s due to surface tension. The cohesive forces of water cause it to bead up rather than spread out.
• Soap Bubbles: Soap bubbles are held together by surface tension. The soap molecules in the bubble’s film reduce surface tension, allowing the bubble to form and hold its shape.
• Droplets on a Needle: When you touch the surface of water with a fine needle, it can cause water to form a droplet at the tip of the needle. This is due to the surface tension of water trying to minimize its surface area.

Surface tension plays a significant role in various natural phenomena and everyday experiences, as demonstrated by these examples.

Surface Tension Science Experiment for Kids

Science is hands-on and fun for kids. The great part is that kids learn something while doing experiments that they enjoy! With a little bit of knowledge, you can easily bring this learning into your home and classroom.

Surface tension experiments can be both fun and educational for kids. These experiments help children understand the concept of surface tension, which is the property of the surface of a liquid that allows it to resist an external force due to the cohesive nature of its molecules.

Surface Tension Science Activities

#1 – floating paper clip.

You’ll need a bowl of water, a paper clip, and a tissue or small piece of aluminum foil. Kids can place the paperclip gently on the surface of the water. They’ll observe how the water’s surface tension allows the paperclip to float.

#2 – Magic Milk

For this experiment, you’ll need a shallow dish, milk, food coloring, and liquid dish soap. Pour a small amount of milk into the dish, add a few drops of different food coloring, and then add a drop of dish soap in the center. Kids will be amazed as they watch the colors race to the edges of the dish due to changes in surface tension.

#3 – Floating Needle

Gather a bowl of water and a sewing needle. Slowly and carefully place the needle on the surface of the water. Kids will see that the needle can float on the surface due to surface tension.

#4 – Soap Boat

This experiment requires a small piece of aluminum foil, a bowl of water, and a bar of soap. Kids can cut the aluminum foil into the shape of a small boat and place it in the water. Then, they can carefully touch the soap to the water near the boat, and they’ll observe how the boat moves due to changes in surface tension.

#5 – Water Droplets on a Coin

Kids can place a clean, dry coin on a flat surface and carefully add water droplets one at a time using a dropper. They’ll notice how the water forms droplets and doesn’t immediately spread out due to surface tension.

#6 – Soap Bubbles

Making soap bubbles is a classic surface tension experiment. You’ll need a solution of water and dish soap and a bubble wand or straw. Kids can dip the wand or straw into the solution and gently blow it to create bubbles. They’ll learn how surface tension creates the thin film of the bubble.

#7 – Floating Pepper

Fill a bowl with water and sprinkle a small amount of pepper on the surface. Kids can then dip their finger, which has a tiny bit of liquid dish soap on it, into the water near the pepper. They’ll observe the pepper moving away from the soap as the surface tension is disrupted.

#8 – Water Bridge

Place two identical cups close together on a flat surface and fill them with water. Use a straw to create a bridge between the two cups by carefully touching the surface of the water in each cup. Kids will see a water bridge forming due to surface tension.

Remember to always supervise kids during these experiments, especially when handling small objects and liquids, and ensure they understand the safety precautions involved. These experiments can help children learn about the properties of water and surface tension in an engaging and hands-on way.

Easy Surface Tension Experiment with Dish Soap

* I used a circular bowl first, then we used a longer Pyrex bowl, which worked better because there was more space for the boat to speed off

• Cut a triangle from the card stock for your “boat”
• Fill your bowl with water*
• Gently place the triangle on top of the water (introduce the concept of surface tension)
• Place a small amount of dish soap on a finger
• Dip the fingertip into the water behind the “boat”
• Observe the boat speed off
• Encourage and ask questions

What is the Science Behind Surface Tension?

Surface tension is a fascinating phenomenon in fluid dynamics that arises due to the cohesive forces between the molecules of a liquid. It’s responsible for several interesting behaviors and effects, such as the ability of small insects to walk on water, the formation of droplets, and the shape of liquid surfaces.

Here’s a brief overview of the science behind surface tension:

• Molecular Cohesion: Surface tension is primarily a result of the cohesive forces between liquid molecules. These forces are primarily caused by intermolecular interactions, such as van der Waals forces and hydrogen bonding, depending on the nature of the liquid. These forces cause molecules at the surface of the liquid to be attracted to their neighboring molecules beneath the surface.
• Unequal Forces: Molecules inside the liquid experience cohesive forces from all directions because they are surrounded by other liquid molecules. However, molecules at the surface do not have molecules above them to balance the cohesive forces. This imbalance in forces results in a net inward force, which acts to minimize the surface area of the liquid.
• Energy Minimization: Nature tends to minimize the energy of a system. In the case of a liquid, minimizing the surface area minimizes the energy associated with the surface. As a result, liquids naturally form shapes that minimize their surface area, which is usually a sphere for small droplets or a flat surface for larger bodies of liquid.
• Mathematical Expression: Surface tension is quantified by a physical property called surface tension coefficient (symbolized as σ), which is measured in units of force per unit length (e.g., N/m or dyn/cm). It represents the amount of force required to increase the length of a liquid interface by a unit amount. The higher the surface tension, the more difficult it is to increase the surface area of the liquid.
• Effects of Surface Tension: Surface tension is responsible for various everyday phenomena, such as the formation of water droplets, capillary action (the rise of liquids in narrow tubes), the ability of small objects to float on the surface of water, and the shape of liquid menisci in narrow containers.
• Contact Angle: When a liquid wets a solid surface, the angle at which the liquid meets the solid is called the contact angle. The contact angle is determined by the balance between adhesive forces (liquid-solid interaction) and cohesive forces (liquid-liquid interaction) and is influenced by surface tension.
• Surfactants: Substances known as surfactants (surface-active agents) can reduce surface tension by interfering with the cohesive forces between liquid molecules. Surfactants are commonly used in detergents and soaps to help break up and remove dirt and grease from surfaces.

Surface tension is a result of the attractive forces between liquid molecules, which causes the surface of a liquid to behave like a stretched elastic membrane. It plays a crucial role in many natural and industrial processes and is a fundamental concept in fluid mechanics.

Magic Finger Pepper Experiment for Kids

Learning Science Kindergartners Preschoolers Toddlers Experiment Kitchen Water Activities 4 Comments

Alisha shares this super simple surface tension science experiment  for kids will leave your kiddos amazed!

In my home, we call this the Magic Finger trick. It’s a great way to get your toddlers, preschoolers, and school-aged kiddos interested in the wonders and joys of science.

Best part – there’s no setup!

Here are 30 other great experiments to do with your preschooler!

You only need three supplies for this surface tension experiment; all of the items are found in your kitchen.

• A bowl of water

Begin by grabbing a bowl from your cabinet and fill it up with water at least half way.

Next, sprinkle some pepper into the bowl of water. Use enough pepper to cover the top of the water.

Then, prepare your kiddos for the amazement that is about to occur.

Simply put some dish soap on the tip of your finger and touch the middle of the water.

Your little ones might think it is magic…

…but in fact there is real science behind the experiment.

When the soap touches the water, the surface tension changes, and the pepper no longer floats on top. But the water molecules still want to keep the surface tension, so they pull back away from the soap, and carry the pepper along with them.

After doing the experiment and talking about surface tension, let your kiddos take a turn using their magic finger.

Here are some great water activities for toddlers!

An extension of this surface tension experiment for kids would be to try other objects on the water.

• Would rice react the same way as the pepper?
• Would pom poms (affiliate link) be too big to react to the surface tension change?

Did you find any other items that reacted the same way as the pepper?

About alisha warth.

I have raised my children doing activities with them. As a homeschool mom, I am always looking for ways to make our learning fun. I'm honored to be able to contribute my ideas to the awesome site that is Hands On As We Grow.

More Hands on Kids Activities to Try

Reader Interactions

sharon Klass says

January 10, 2019 at 12:07 pm

Hi, I haven’t tried this with kids yet but I had so much fun doing it myself I know my kiddoes will too. I thank you so much for the seven day challenge, I’m so excited about all the activities and the suggestions. Thank you Sharon K.

August 19, 2018 at 7:32 pm

Thank you foe sharing your great ideas. Its very helpful.

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Detergents, soaps and surface tension

In association with Nuffield Foundation

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Various experiments to observe the effects of detergents and soaps on the surface tension of purified and hard water

A fine insoluble powder, such as talcum powder, is sprinkled on a clean water surface in a beaker, a drop of detergent or soap solution added to the centre, and the effect observed as the surface tension of the water is changed. This can be repeated with other powders after cleaning the beaker and using fresh water samples. A needle can be carefully floated on a clean water surface and the effect of adding detergent or soap observed. Finally the same experiments can be repeated using samples of hard water to compare the effects.

This is a series of quick, simple, class experiments which can be extended or shortened as desired. Each experiment should take no more than two minutes, though the cleaning of the beaker between experiments may take up more time than expected. If a full range of experiments is desired, the time taken could amount to 30 minutes, but this may not be justified in terms of the learning objectives concerned.

• Beaker (250 cm 3 )
• Glass stirring rod
• Clean sewing needle (note 1)

Apparatus notes

• The sewing needle should be a fine needle, and for safety issued to students with the pointed end inserted into a piece of card bearing a safety warning about handling the needle.
• Talcum powder, in pepper pot or similar dispenser
• Other powders (see technical notes)
• Liquid detergent in a dropping bottle
• Liquid soap in a dropping bottle
• Access to a supply of purified water (distilled or deionised), about 1 dm 3  per working group
• Access to a supply of hard water

Health, safety and technical notes

• Read our standard health and safety guidance
• Other powders – Any powders used other than talcum powder, such as lycopodium powder or carbon powder, should be subject to a risk assessment. Lycopodium powder is a potential allergen.
• Liquid detergent – Any washing-up liquid or multipurpose detergent will suffice.
• Liquid soap - Genuine liquid soap or soap flakes from which the liquid can be made, is increasingly difficult to obtain. Wanklyn’s and Clarke’s soap solutions should still be available from chemical suppliers. Lux soap flakes are ideal for making liquid soap if you can source them. Granny’s Original and other non-branded soap flakes work fine but need to be used in solution as soon as they are made. They do not form a stable emulsion and precipitate out overnight. Note that most liquid hand washes are based on the same detergents as washing-up liquids and do not contain soap. To obtain soap solution from soap flakes – dissolve soap flakes (or shavings from a bar of soap) in ethanol – use IDA (Industrial Denatured Alcohol) (HIGHTLY FLAMMABLE, HARMFUL) – see CLEAPSS Hazcard HC040a and CLEAPSS Recipe Book RB000. Do not dilute with water.
• Hard water – A supply of hard water can be made by stirring solid calcium sulfate into a large volume of tap water, allowing to stand for some time then, after the undissolved solid has settled out, decanting the clear solution into a container suitable for students to collect their samples as required. Label as ‘Hard Water’. Allow about 1 dm 3  for each working group in the class.
• Half fill the beaker with purified water.
• Sprinkle the water surface carefully with a fine layer of powder.
• Add one drop only of detergent in the middle of the water surface. Observe what happens. Does the talcum powder stay on the surface, or does it sink?
• Clean the beaker thoroughly, half-fill again with purified water, and repeat steps two and three using a drop of liquid soap instead of detergent. Compare what happens to what happened in the previous experiment.
• Repeat steps three   and four, only this time use hard water instead of purified water. Are the results different from those obtained with purified water? If so, in what ways?
• Other powders may be available to test instead of talcum powder, to see whether the type of powder makes any difference. If you do test any of these, what differences do you find?
• Again using a clean beaker with purified water, try to float a fine sewing needle on the surface by carefully lowering it into the beaker, avoiding breaking the surface with your fingers, and dropping it from as close above the surface as possible. Once you have a needle floating, add a small drop of detergent to the water, but away from the needle. What happens?

Teaching notes

This series of brief experiments on the surface tension of water, and the effects of detergents and soaps on this, can serve as an introduction to the phenomenon of surface tension, with a discussion of results leading into simple theory. Alternatively, it could be used to illustrate prior teaching of the topic, leading to discussion of what is happening when detergents and soaps are added, including the differences found with hard water.

A diagram of the forces between water molecules at the surface and centre of a liquid.

There is a net force of attraction between the molecules of water (or any other liquid) holding the molecules together. For a molecule in the middle of the liquid, these forces, acting equally in all directions, more or less balancing out. For a molecule in the surface layer of the liquid, the forces do not balance out, and all the molecules in the surface layer are pulled towards each other and towards the bulk of the liquid. This brings these molecules closer to their neighbours until increasing forces of repulsion create a new balance, and gives rise to the phenomenon of surface tension.

When an object falls onto the surface, it has to push the water molecules apart. If the effect of the weight of the object is insufficient to match the attractive forces between molecules in the surface layer, the object will not enter the surface. Careful observation of the floating needle will show that the water surface is bent down under the weight of the needle, the surface tension causing it to behave as if the needle was supported by a flexible skin.

A diagram of the forces enabling a needle to float on water

Molecules of most detergents and soaps are long chain hydrocarbon molecules with an ionic group at one end, usually carrying a negative charge, thus making it an anion. This charge is balanced by the opposite charge of a soluble cation, for example Na + . The long hydrocarbon chains do not interact well with water molecules, and many of them are effectively ‘squeezed out’ to the interfaces between the water and the air or the glass sides of the beaker. The effect of these molecules on the water surface is to considerably weaken the forces between water molecules there, thus lowering the surface tension.

A diagram of a detergent or soap molecule, which is responsible for breaking down surface tension

When the drop of detergent is added to the powdered surface, the initial effect is to draw the powder back to the edges very rapidly as the detergent molecules form their own surface layer with a lower surface tension than the water. As the detergent gradually mixes with the water, the powder begins to sink, and a needle will now pass through the surface with ease under its own weight. However, if lycopodium powder is used, which is less dense than water, it remains at the edges. Other powders may clump into nodules if they are not wetted by the detergent solution.

A diagram showing detergent molecules in a beaker of water, some lining the surfaces and other forming clumps

In hard water there is a significant concentration of calcium, Ca 2+ , and/or magnesium, Mg 2+ , cations. These cations form an insoluble compound with soap anions, so instead of forming a surface layer, they are precipitated out, leaving the surface tension largely unchanged.

2COO − (aq) + Ca 2+ (aq) → (COO) 2 Ca(s)

However, the calcium and magnesium salts of many detergent molecules are soluble, so detergents lower the surface tension of hard water.

Additional information

This is a resource from the  Practical Chemistry project , developed by the Nuffield Foundation and the Royal Society of Chemistry. This collection of over 200 practical activities demonstrates a wide range of chemical concepts and processes. Each activity contains comprehensive information for teachers and technicians, including full technical notes and step-by-step procedures. Practical Chemistry activities accompany  Practical Physics  and  Practical Biology . 

© Nuffield Foundation and the Royal Society of Chemistry

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Easy Science: Surface Tension Water Drop Races

Science experiments don't need to be complicated! A water drop race is a simple science project is a great was to pass the time when you need a quick distraction for your kids. It can be part of an in-depth classroom exploration into the concept of surface tension and molecule cohesion.

What is Surface Tension?

Surface tension is

the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. The molecules at the surface of a glass of water do not have other water molecules on all sides of them and consequently they cohere more strongly to those directly associated with them. USGA

A classic kids surface tension experiment is the one where you drip water drop by drop onto a penny. You can also observe surface tension by floating a paper clip on the surface of water.

Bugs also use surface tension to hang out on ponds and streams. Leaves during a rain storm also demonstrate water's cohesive nature.

For this water drop race experiment, surface tension is responsible for the spherical shape of the water droplets. The waxy paper keeps the water from being absorbed away by the surface they sit on.

However, even if your child is too young to grasp the concepts of surface tension and the bonding properties of water molecules, it's still a super fun indoor activity that will make kids say, "Cool!!!"

Water Drop Surface Tension Experiment

How to conduct water drop races

You will need: one straw per scientist glass of water water dropper wax paper or parchment paper

Observations

Kids will start to notice ways in which they can control their water drops. Young scientists can explore surface tension strength by blowing air through the straw extra hard, which will cause larger water drops break up into smaller water beads.

Kids will also learn how to blow water beads together to merge them into larger droplets. No doubt, they will have fun sucking water drops up the straw and blowing them back out! My kid loved blowing his off the table to "plop" on the floor! ( It's just water, after all. )

Conclusions

Whether or not you use this surface tension experiment to go into depth about how water molecules, tension and cohesion work, water drop races provide lots of entertainment!

I absolutely loved how this project has the added bonus of keeping the kids busy for an extended period of time without a lot parental involvement. And because it's just a small amount of water that is used, you won't have to worry about everything getting wet or the kids making a big mess to clean up!

More water experiments

• Water refraction is just like magic!
• Amaze your kids with a leak proof hole in a bag!
• Make a coin jump off a bottle
• All our favorite indoor water activities

I First Published this idea 3/16/09.

Reader Interactions

Leptir says

June 04, 2010 at 9:14 am

Looks like fun 🙂 I'll probably try it in my classroom with kids. Thanks for sharing 🙂

MaryAnne says

June 04, 2010 at 12:15 pm

What an excellent activity! Thanks for the idea =)

June 05, 2010 at 1:44 am

Christy says

June 05, 2010 at 5:33 pm

My kids will love this! Thanks.

Raising a Happy Child says

June 09, 2010 at 11:14 am

I have to try it out - wind races have been popular here, but we haven't done them with water.

September 12, 2016 at 5:29 pm

Hi! I'm about to launch a year-long science course for young kids at some of the local schools. I love this idea! It will be a PERFECT fun activity to end the "Surface tension" lesson with! We'll be doing some fun experiments to bring the concept home to the kids, and this is just what I needed! Thanks so much Erica!

September 14, 2016 at 12:16 pm

Glad the idea was useful!

Julie C Billow says

April 17, 2017 at 12:45 am

I just tried this out myself and had fun! Try adding some color to the experiment by drawing on the waxed paper with markers and then watch as the water drops blow through the colors and absorb them. Fascinating!

April 19, 2017 at 11:07 am

I love that idea!

March 09, 2018 at 3:22 pm

Used this today with my preschool kids. Many had fun watching the water break apart and go back together. I added food coloring to the water and used freezer paper ??

Rebecca says

March 28, 2019 at 3:00 pm

We used color waters and blew the the color water droplets into each other to see what colors they turned into. The kids loved it.

March 29, 2019 at 8:08 am

What a fantastic idea!

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Science Projects > Physics & Engineering Projects > Water Experiments  

Water Experiments

Surface tension experiments.

Surface tension is one of the most important properties of water .

It is the reason that water collects in drops, but it’s also why plant stems can “ drink water ,” and cells can receive water through the smallest blood vessels.

You can test multiple surface tension experiments using just a few household items.

What You Do:

1. Start with a cup of water and some paperclips. Do you think a paperclip will float in the water? Drop one in the cup to find out. Since the paperclip is denser than the water, it will sink to the bottom of the cup.

Now find out if you can use surface tension to float the paperclip. Instead of dropping the paperclip into the cup, gently lay it flat on the surface of the water.

(This is tricky — it may help to place a piece of paper towel slightly bigger than the paperclip in the water. Then lay the paperclip on top of it. In a minute or so, the paper towel will sink, leaving the paperclip floating on top of the water.)

2. Even though the paperclip is still denser than the water, the strong attraction between the water molecules on the surface forms a type of ‘skin’ that supports the clip.

3. Now put a drop of dish soap in the water. This will bind with the water molecules, interfering with the surface tension .

The paper clip will sink. You can try floating other things on top of the water also – pepper floats well until you add dish soap. Can you find any other light items that will float?

Surface tension creates the ‘skin’ on top of the water, but it is also what causes water to stick together in drops.

Observe how these drops stick together by experimenting with water and a penny. All you need is a cup of water, a penny, and a medicine dropper .

First make a prediction: how many drops of water do you think you can fit on the top surface of the penny? Add one drop. After seeing how much room it takes, do you want to rethink your first prediction?

Now continue carefully adding drops until the water spills off the penny. Try this three times, recording the number of drops each time, and then find the average number of drops that can fit.

Surface tension is the reason you can fit so much water on the penny. The water molecules attract each other, pulling together so the water doesn’t spill.

Try this experiment with different-sized coins. Predict how many drops you can fit on a quarter compared with the penny.

For one final surface tension experiment, start with a full glass of water. Predict how many pennies you can add to the water without the glass overflowing. Gently add pennies one by one. Because of surface tension, the water will rise above the rim of the glass before it spills! Compare your original prediction with the number of pennies you were able to add.

Freezing Point

Have you ever wondered why rivers and lakes freeze in the winter, but oceans do not? In this experiment we will see that it is the presence of salt in the ocean that makes it less likely to freeze.

What You Need:

• 1-gallon freezer bag
• 1-quart freezer bag
• crushed ice
• thermometer

1. Fill the gallon freezer bag half full with crushed ice. Add one cup of salt and seal the bag. Put on some gloves and knead the ice and salt until the ice has completely melted.

2. Use the thermometer to record the temperature of the saltwater mixture. Even though the ice has melted, the temperature should be less than 32°F (0°C).

3. Now put about an ounce of water in the quart freezer bag. Seal the quart bag and then put it in the saltwater mixture in the larger bag. Seal the larger bag also and leave it until the water inside the quart bag freezes.

How did the water freeze when surrounded only by saltwater?

The salt broke apart the bonds between the water molecules in the ice, causing it to melt, but the temperature remained below the freezing point for pure water.

Salt (and other substances dissolved in water) will always lower the freezing point .

This is why water in the ocean rarely freezes.

• Find out more about salt water by making a Solar Purifier

More Water Projects:

•   Liquid Density
•   Hot Water: Convection Science
•  Water Wheel

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Testing Surface Tension

Surface tension is why feathers, canoes, and even snakes can float on top of the water. But what about the surface tension of other liquids? Or what happens when you add soap to water? Let’s find out!

HYPOTHESIS:  When the surface tension of liquids is changed, it changes a liquid’s ability to allow objects to float.

Supplies needed:

Here is what you do:, how many pebbles can the bowl hold until it sinks, ask yourself:, conclusion:, find out more: .

How is it possible for people to float on top of water AND sink or drown?

Science Fun

Surface Tension Art

• Acrylic paints
• Straws, small paint brushes, or short pieces of yarn
• A toothpick
• A plate or plastic container
• Artists’ paper (sketchpad paper, watercolor paper, or Bristol board work well)
• Cups or containers for paint and soap

Instructions:

• Cover your work surface with paper towels.
• In the cups, mix two or three paint colors with water in roughly equal parts.
• Add a drop of soap and a few drops of water to another cup.
• Pour enough water onto the plate to cover the bottom.
• Using the straws, add drops of paint to the surface of the water by dipping a straw into a paint cup then gently touching the surface of the water with the straw.
• Use a toothpick dipped in soap to break up the paint colors and form patterns.
• Take a piece of paper small enough to fit on the surface of the water and lay it gently in the center of the plate. Let it soak for 5-10 seconds, then carefully lift it off and set it onto a paper towel. Use another paper towel to gently pat the surface of the paper dry.

WATCH THE QUICK AND EASY VIDEO TUTORIAL

How it Works:

The surface of the water is made up of millions of water molecules. These tiny molecules like to be together, and create surface tension where they meet the air. Surface tension keeps the paint from sinking (mostly). This is how water beetles stay on the surface of ponds and rivers without sinking!

Extra Experiments:

• Try different colors to see which ones show up well.
• Acrylic paints aren’t the only types that work with this method. Oil paints and watercolors may work, certain nail polishes give very colorful results (new polishes work better than old bottles, creamy colors tend to work better than transparent ones).

EXPLORE TONS OF FUN AND EASY SCIENCE EXPERIMENTS!

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37 Water Science Experiments: Fun & Easy

We’ve curated a diverse selection of water related science experiments suitable for all ages, covering topics such as density, surface tension, water purification, and much more.

These hands-on, educational activities will not only deepen your understanding of water’s remarkable properties but also ignite a passion for scientific inquiry.

So, grab your lab coat and let’s dive into the fascinating world of water-based science experiments!

Water Science Experiments

1. walking water science experiment.

This experiment is a simple yet fascinating science experiment that involves observing the capillary action of water. Children can learn a lot from this experiment about the characteristics of water and the capillary action phenomenon. It is also a great approach to promote scientific curiosity and enthusiasm.

Learn more: Walking Water Science Experiment

2. Water Filtration Experiment

A water filtering experiment explains how to purify contaminated water using economical supplies. The experiment’s goal is to educate people about the procedure of water filtration, which is crucial in clearing water of impurities and contaminants so that it is safe to drink.

Learn more: Water Filtration Experiment

3. Water Cycle in a Bag

The water cycle in a bag experiment became to be an enjoyable and useful instructional exercise that helps students understand this idea. Participants in the experiment can observe the many water cycle processes by building a model of the water cycle within a Ziplock bag.

4. Cloud in a Jar

The rain cloud in a jar experiment is a popular instructional project that explains the water cycle and precipitation creation. This experiment is best done as a water experiment since it includes monitoring and understanding how water changes state from a gas (water vapor) to a liquid (rain) and back to a gas.

Learn more: Cloud in a Jar

5. The Rising Water

The rising water using a candle experiment is a wonderful way to teach both adults and children the fundamentals of physics while also giving them an exciting look at the properties of gases and how they interact with liquids.

6. Leak Proof Bag Science Experiment

In the experiment, a plastic bag will be filled with water, and after that, pencils will be inserted through the bag without causing it to leak.

The experiments explain how the plastic bag’s polymer chains stretch and form a barrier that keeps water from dripping through the holes the pencils have produced.

Learn more: Leak Proof Bag Science Experiment

7. Keep Paper Dry Under Water Science Experiment

The experiment is an enjoyable way for demonstrating air pressure and surface tension for both adults and children. It’s an entertaining and engaging technique to increase scientific curiosity and learn about scientific fundamentals.

Learn more: Keep Paper Dry Under Water Science Experiment

8. Frozen Water Science Experiment

The Frozen Water Science Experiment is a fun and engaging project that teaches about the qualities of water and how it behaves when frozen.

You can gain a better knowledge of the science behind the freezing process and investigate how different variables can affect the outcome by carrying out this experiment.

9. Make Ice Stalagmites

10. Bending of Light

A fascinating scientific activity that explores visual principles and how light behaves in different surfaces is the “bending of light” water experiment. This experiment has applications in physics, engineering, and technology in addition to being a fun and interesting method to learn about the characteristics of light.

11. Salt on a Stick

This experiment is an excellent way to catch interest, engage in practical learning, and gain a deeper understanding of the characteristics of water and how they relate to other substances. So the “Salt on Stick” water experiment is definitely worth trying if you’re looking for a fun and educational activity to try!

Learn More: Water Cycle Experiment Salt and Stick

12. Separating Mixture by Evaporation

This method has practical applications in fields like water processing and is employed in a wide range of scientific disciplines, from chemistry to environmental science.

You will better understand the principles determining the behavior of mixtures and the scientific procedures used to separate them by performing this experiment at home.

13. Dancing Spaghetti

Have you ever heard of the dancing spaghetti experiment? It’s a fascinating science experiment that combines simple materials to create a mesmerizing visual display.

The dancing spaghetti experiment is not only entertaining, but it also helps you understand the scientific concepts of chemical reactions, gas production, and acidity levels.

14. Magic Color Changing Potion

The magic color-changing potion experiment with water, vinegar, and baking soda must be tried since it’s an easy home-based scientific experiment that’s entertaining and educational.

This experiment is an excellent way to teach kids about chemical reactions and the characteristics of acids and bases while providing them an interesting and satisfying activity.

15. Traveling Water Experiment

In this experiment, you will use simple objects like straws or strings to make a path for water to pass between two or more containers.

Learn more: Rookie Parenting

16. Dry Erase and Water “Floating Ink” Experiment

The dry-erase and water “floating ink” experiment offers an interesting look at the characteristics of liquids and the laws of buoyancy while also being a great method to educate kids and adults to the fundamentals of science.

Learn more: Dry Erase and Water Floating Ink Experiment

17. Underwater Candle

In this experiment, we will investigate a connection between fire and water and learn about the remarkable factors of an underwater candle.

18. Static Electricity and Water

19. Tornado in a Glass

This captivating experiment will demonstrate how the forces of air and water can combine to create a miniature vortex, resembling a tornado.

Learn more: Tornado in a Glass

20. Make Underwater Magic Sand

Be ready to build a captivating underwater world with the magic sand experiment. This experiment will examine the fascinating characteristics of hydrophobic sand, sometimes referred to as magic sand.

21. Candy Science Experiment

Get ready to taste the rainbow and learn about the science behind it with the Skittles and water experiment! In this fun and colorful experiment, we will explore the concept of solubility and observe how it affects the diffusion of color.

Density Experiments

Density experiments are a useful and instructive approach to learn about the characteristics of matter and the fundamentals of science, and they can serve as a starting point for further exploration into the fascinating world of science.

Density experiments may be carried out with simple materials that can be found in most homes.

This experiment can be a great hands-on learning experience for kids and science lovers of all ages.

22. Super Cool Lava Lamp Experiment

The awesome lava lamp experiment is an entertaining and educational activity that illustrates the concepts of density and chemical reactions. With the help of common household items, this experiment involves making a handmade lava lamp.

Learn more: Lava Lamp Science Experiment

23. Denser Than you Think

Welcome to the fascinating world of density science! The amount of matter in a particular space or volume is known as density, and it is a fundamental concept in science that can be seen everywhere around us.

Understanding density can help us figure out why some objects float while others sink in water, or why certain compounds do not mix.

24. Egg Salt and Water

Learn about the characteristics of water, including its density and buoyancy, and how the addition of salt affects these characteristics through performing this experiment.

25. Hot Water and Cold-Water Density

In this experiment, hot and cold water are put into a container to see how they react to one other’s temperatures and how they interact.

Sound and Water Experiments

Have you ever wondered how sound travels through different mediums? Take a look at these interesting sound and water experiments and learn how sounds and water can affect each other.

26. Home Made Water Xylophone

You can do this simple scientific experiment at home using a few inexpensive ingredients to create a handmade water xylophone.

The experiment demonstrates the science of sound and vibration and demonstrates how changing water concentrations can result in a range of tones and pitches.

Learn more: Home Made Water Xylophone

27. Create Water Forms Using Sound!

A remarkable experiment that exhibits the ability of sound waves to influence and impact the physical world around us is the creation of water formations using sound.

In this experiment, sound waves are used to generate patterns and shapes, resulting in amazing, intricate designs that are fascinating to observe.

28. Sound Makes Water Come Alive 

These experiments consist of using sound waves to create water vibrations, which can result in a variety of dynamic and captivating phenomena.

29. Water Whistle

The water whistle experiment includes blowing air through a straw that is submerged in water to produce a whistle.

This experiment is an excellent way to learn about the characteristics of sound waves and how water can affect them.

Water Surface Tension Experiments

You can observe the effects of surface tension on the behavior of liquids by conducting a surface tension experiment.

By trying these experiments, you can gain a better understanding of the properties of liquids and their behavior and how surface tension affects their behavior.

30. Floating Paperclip

In this experiment, you will put a paper clip on the top of the water and observe it float because of the water’s surface tension.

31. Water Glass Surface Tension

Have you ever noticed how, on some surfaces, water drops may form perfect spheres? The surface tension, which is a characteristic of water and the cohesive force that holds a liquid’s molecules together at its surface, is to blame for this.

32. Camphor Powered Boat

The camphor-powered boat experiment is a fun and fascinating way to explore the principles of chemistry, physics, and fluid mechanics. In this experiment, a miniature boat is used to travel across the water’s surface using camphor tablets.

33. Pepper and Soap Experiment

The pepper in a cloud experiment is a simple and interesting activity that explains the concept of surface tension. This experiment includes adding pepper to a bowl of water and then pouring soap to the mixture, causing the pepper to move away from the soap.

Learn more: Pepper and Soap Experiment

Boiling Water Experiments

Experiments with boiling water are an engaging and informative way to learn about physics, chemistry, and water’s characteristics.

These investigations, which include examining how water behaves when it changes temperature and pressure, can shed light on a variety of scientific phenomena.

It’s important to take the proper safety measures when performing experiments with hot water. Boiling water can produce steam and hot particles that are dangerous to inhale in and can result in severe burns if it comes into contact with skin.

34. Make It Rain

This experiment can be accomplished using basic supplies that can be found in most homes, make it an excellent opportunity for hands-on learning for both kids and science lovers.

Learn more: Make it Rain

35. Fire Water Balloons

Learning about the fundamentals of thermodynamics, the behavior of gases, and the effects of heat on objects are all made possible by this experiment.

36. Boil Water with Ice

The Boiling Water with Ice experiment is an engaging and beneficial approach to learn about temperature and the behavior of water. It can also serve as an introduction for further discovery into the wonderful world of science.

37. Boil Water in a Paper Cup

The “boil water in a cup” experiment is an easier but powerful approach to illustrate the idea of heat transmission by conduction. This experiment is often used in science classes to teach students about thermal conductivity and the physics of heat transfer.

Similar Posts:

• 68 Best Chemistry Experiments: Learn About Chemical Reactions
• Top 50 Fun Food Science Experiments
• Top 100 Fine Motor Skills Activities for Toddlers and Preschoolers

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72 Easy Science Experiments Using Materials You Already Have On Hand

Because science doesn’t have to be complicated.

If there is one thing that is guaranteed to get your students excited, it’s a good science experiment! While some experiments require expensive lab equipment or dangerous chemicals, there are plenty of cool projects you can do with regular household items. We’ve rounded up a big collection of easy science experiments that anybody can try, and kids are going to love them!

Easy Chemistry Science Experiments

Easy physics science experiments, easy biology and environmental science experiments, easy engineering experiments and stem challenges.

1. Taste the Rainbow

Teach your students about diffusion while creating a beautiful and tasty rainbow! Tip: Have extra Skittles on hand so your class can eat a few!

Learn more: Skittles Diffusion

2. Crystallize sweet treats

Crystal science experiments teach kids about supersaturated solutions. This one is easy to do at home, and the results are absolutely delicious!

Learn more: Candy Crystals

3. Make a volcano erupt

This classic experiment demonstrates a chemical reaction between baking soda (sodium bicarbonate) and vinegar (acetic acid), which produces carbon dioxide gas, water, and sodium acetate.

Learn more: Best Volcano Experiments

4. Make elephant toothpaste

This fun project uses yeast and a hydrogen peroxide solution to create overflowing “elephant toothpaste.” Tip: Add an extra fun layer by having kids create toothpaste wrappers for plastic bottles.

5. Blow the biggest bubbles you can

Add a few simple ingredients to dish soap solution to create the largest bubbles you’ve ever seen! Kids learn about surface tension as they engineer these bubble-blowing wands.

Learn more: Giant Soap Bubbles

6. Demonstrate the “magic” leakproof bag

All you need is a zip-top plastic bag, sharp pencils, and water to blow your kids’ minds. Once they’re suitably impressed, teach them how the “trick” works by explaining the chemistry of polymers.

Learn more: Leakproof Bag

7. Use apple slices to learn about oxidation

Have students make predictions about what will happen to apple slices when immersed in different liquids, then put those predictions to the test. Have them record their observations.

Learn more: Apple Oxidation

8. Float a marker man

Their eyes will pop out of their heads when you “levitate” a stick figure right off the table! This experiment works due to the insolubility of dry-erase marker ink in water, combined with the lighter density of the ink.

Learn more: Floating Marker Man

9. Discover density with hot and cold water

There are a lot of easy science experiments you can do with density. This one is extremely simple, involving only hot and cold water and food coloring, but the visuals make it appealing and fun.

Learn more: Layered Water

10. Layer more liquids

This density demo is a little more complicated, but the effects are spectacular. Slowly layer liquids like honey, dish soap, water, and rubbing alcohol in a glass. Kids will be amazed when the liquids float one on top of the other like magic (except it is really science).

Learn more: Layered Liquids

11. Grow a carbon sugar snake

Easy science experiments can still have impressive results! This eye-popping chemical reaction demonstration only requires simple supplies like sugar, baking soda, and sand.

Learn more: Carbon Sugar Snake

12. Mix up some slime

Tell kids you’re going to make slime at home, and watch their eyes light up! There are a variety of ways to make slime, so try a few different recipes to find the one you like best.

13. Make homemade bouncy balls

These homemade bouncy balls are easy to make since all you need is glue, food coloring, borax powder, cornstarch, and warm water. You’ll want to store them inside a container like a plastic egg because they will flatten out over time.

Learn more: Make Your Own Bouncy Balls

14. Create eggshell chalk

Eggshells contain calcium, the same material that makes chalk. Grind them up and mix them with flour, water, and food coloring to make your very own sidewalk chalk.

Learn more: Eggshell Chalk

15. Make naked eggs

This is so cool! Use vinegar to dissolve the calcium carbonate in an eggshell to discover the membrane underneath that holds the egg together. Then, use the “naked” egg for another easy science experiment that demonstrates osmosis .

Learn more: Naked Egg Experiment

16. Turn milk into plastic

This sounds a lot more complicated than it is, but don’t be afraid to give it a try. Use simple kitchen supplies to create plastic polymers from plain old milk. Sculpt them into cool shapes when you’re done!

17. Test pH using cabbage

Teach kids about acids and bases without needing pH test strips! Simply boil some red cabbage and use the resulting water to test various substances—acids turn red and bases turn green.

Learn more: Cabbage pH

18. Clean some old coins

Use common household items to make old oxidized coins clean and shiny again in this simple chemistry experiment. Ask kids to predict (hypothesize) which will work best, then expand the learning by doing some research to explain the results.

Learn more: Cleaning Coins

19. Pull an egg into a bottle

This classic easy science experiment never fails to delight. Use the power of air pressure to suck a hard-boiled egg into a jar, no hands required.

Learn more: Egg in a Bottle

20. Blow up a balloon (without blowing)

Chances are good you probably did easy science experiments like this when you were in school. The baking soda and vinegar balloon experiment demonstrates the reactions between acids and bases when you fill a bottle with vinegar and a balloon with baking soda.

21 Assemble a DIY lava lamp

This 1970s trend is back—as an easy science experiment! This activity combines acid-base reactions with density for a totally groovy result.

22. Explore how sugary drinks affect teeth

The calcium content of eggshells makes them a great stand-in for teeth. Use eggs to explore how soda and juice can stain teeth and wear down the enamel. Expand your learning by trying different toothpaste-and-toothbrush combinations to see how effective they are.

Learn more: Sugar and Teeth Experiment

23. Mummify a hot dog

If your kids are fascinated by the Egyptians, they’ll love learning to mummify a hot dog! No need for canopic jars , just grab some baking soda and get started.

24. Extinguish flames with carbon dioxide

This is a fiery twist on acid-base experiments. Light a candle and talk about what fire needs in order to survive. Then, create an acid-base reaction and “pour” the carbon dioxide to extinguish the flame. The CO2 gas acts like a liquid, suffocating the fire.

25. Send secret messages with invisible ink

Turn your kids into secret agents! Write messages with a paintbrush dipped in lemon juice, then hold the paper over a heat source and watch the invisible become visible as oxidation goes to work.

Learn more: Invisible Ink

26. Create dancing popcorn

This is a fun version of the classic baking soda and vinegar experiment, perfect for the younger crowd. The bubbly mixture causes popcorn to dance around in the water.

27. Shoot a soda geyser sky-high

You’ve always wondered if this really works, so it’s time to find out for yourself! Kids will marvel at the chemical reaction that sends diet soda shooting high in the air when Mentos are added.

Learn more: Soda Explosion

28. Send a teabag flying

Hot air rises, and this experiment can prove it! You’ll want to supervise kids with fire, of course. For more safety, try this one outside.

Learn more: Flying Tea Bags

29. Create magic milk

This fun and easy science experiment demonstrates principles related to surface tension, molecular interactions, and fluid dynamics.

Learn more: Magic Milk Experiment

30. Watch the water rise

Learn about Charles’s Law with this simple experiment. As the candle burns, using up oxygen and heating the air in the glass, the water rises as if by magic.

Learn more: Rising Water

31. Learn about capillary action

Kids will be amazed as they watch the colored water move from glass to glass, and you’ll love the easy and inexpensive setup. Gather some water, paper towels, and food coloring to teach the scientific magic of capillary action.

Learn more: Capillary Action

32. Give a balloon a beard

Equally educational and fun, this experiment will teach kids about static electricity using everyday materials. Kids will undoubtedly get a kick out of creating beards on their balloon person!

Learn more: Static Electricity

33. Find your way with a DIY compass

Here’s an old classic that never fails to impress. Magnetize a needle, float it on the water’s surface, and it will always point north.

Learn more: DIY Compass

34. Crush a can using air pressure

Sure, it’s easy to crush a soda can with your bare hands, but what if you could do it without touching it at all? That’s the power of air pressure!

35. Tell time using the sun

While people use clocks or even phones to tell time today, there was a time when a sundial was the best means to do that. Kids will certainly get a kick out of creating their own sundials using everyday materials like cardboard and pencils.

Learn more: Make Your Own Sundial

36. Launch a balloon rocket

Grab balloons, string, straws, and tape, and launch rockets to learn about the laws of motion.

37. Make sparks with steel wool

All you need is steel wool and a 9-volt battery to perform this science demo that’s bound to make their eyes light up! Kids learn about chain reactions, chemical changes, and more.

Learn more: Steel Wool Electricity

38. Levitate a Ping-Pong ball

Kids will get a kick out of this experiment, which is really all about Bernoulli’s principle. You only need plastic bottles, bendy straws, and Ping-Pong balls to make the science magic happen.

39. Whip up a tornado in a bottle

There are plenty of versions of this classic experiment out there, but we love this one because it sparkles! Kids learn about a vortex and what it takes to create one.

Learn more: Tornado in a Bottle

40. Monitor air pressure with a DIY barometer

This simple but effective DIY science project teaches kids about air pressure and meteorology. They’ll have fun tracking and predicting the weather with their very own barometer.

Learn more: DIY Barometer

41. Peer through an ice magnifying glass

Students will certainly get a thrill out of seeing how an everyday object like a piece of ice can be used as a magnifying glass. Be sure to use purified or distilled water since tap water will have impurities in it that will cause distortion.

Learn more: Ice Magnifying Glass

42. String up some sticky ice

Can you lift an ice cube using just a piece of string? This quick experiment teaches you how. Use a little salt to melt the ice and then refreeze the ice with the string attached.

Learn more: Sticky Ice

43. “Flip” a drawing with water

Light refraction causes some really cool effects, and there are multiple easy science experiments you can do with it. This one uses refraction to “flip” a drawing; you can also try the famous “disappearing penny” trick .

Learn more: Light Refraction With Water

44. Color some flowers

We love how simple this project is to re-create since all you’ll need are some white carnations, food coloring, glasses, and water. The end result is just so beautiful!

45. Use glitter to fight germs

Everyone knows that glitter is just like germs—it gets everywhere and is so hard to get rid of! Use that to your advantage and show kids how soap fights glitter and germs.

Learn more: Glitter Germs

46. Re-create the water cycle in a bag

You can do so many easy science experiments with a simple zip-top bag. Fill one partway with water and set it on a sunny windowsill to see how the water evaporates up and eventually “rains” down.

Learn more: Water Cycle

47. Learn about plant transpiration

Your backyard is a terrific place for easy science experiments. Grab a plastic bag and rubber band to learn how plants get rid of excess water they don’t need, a process known as transpiration.

Learn more: Plant Transpiration

48. Clean up an oil spill

Before conducting this experiment, teach your students about engineers who solve environmental problems like oil spills. Then, have your students use provided materials to clean the oil spill from their oceans.

Learn more: Oil Spill

49. Construct a pair of model lungs

Kids get a better understanding of the respiratory system when they build model lungs using a plastic water bottle and some balloons. You can modify the experiment to demonstrate the effects of smoking too.

Learn more: Model Lungs

50. Experiment with limestone rocks

Kids  love to collect rocks, and there are plenty of easy science experiments you can do with them. In this one, pour vinegar over a rock to see if it bubbles. If it does, you’ve found limestone!

Learn more: Limestone Experiments

51. Turn a bottle into a rain gauge

All you need is a plastic bottle, a ruler, and a permanent marker to make your own rain gauge. Monitor your measurements and see how they stack up against meteorology reports in your area.

Learn more: DIY Rain Gauge

52. Build up towel mountains

This clever demonstration helps kids understand how some landforms are created. Use layers of towels to represent rock layers and boxes for continents. Then pu-u-u-sh and see what happens!

Learn more: Towel Mountains

53. Take a play dough core sample

Learn about the layers of the earth by building them out of Play-Doh, then take a core sample with a straw. ( Love Play-Doh? Get more learning ideas here. )

Learn more: Play Dough Core Sampling

54. Project the stars on your ceiling

Use the video lesson in the link below to learn why stars are only visible at night. Then create a DIY star projector to explore the concept hands-on.

Learn more: DIY Star Projector

55. Make it rain

Use shaving cream and food coloring to simulate clouds and rain. This is an easy science experiment little ones will beg to do over and over.

Learn more: Shaving Cream Rain

56. Blow up your fingerprint

This is such a cool (and easy!) way to look at fingerprint patterns. Inflate a balloon a bit, use some ink to put a fingerprint on it, then blow it up big to see your fingerprint in detail.

57. Snack on a DNA model

Twizzlers, gumdrops, and a few toothpicks are all you need to make this super-fun (and yummy!) DNA model.

Learn more: Edible DNA Model

58. Dissect a flower

Take a nature walk and find a flower or two. Then bring them home and take them apart to discover all the different parts of flowers.

59. Craft smartphone speakers

No Bluetooth speaker? No problem! Put together your own from paper cups and toilet paper tubes.

Learn more: Smartphone Speakers

60. Race a balloon-powered car

Kids will be amazed when they learn they can put together this awesome racer using cardboard and bottle-cap wheels. The balloon-powered “engine” is so much fun too.

Learn more: Balloon-Powered Car

61. Build a Ferris wheel

You’ve probably ridden on a Ferris wheel, but can you build one? Stock up on wood craft sticks and find out! Play around with different designs to see which one works best.

Learn more: Craft Stick Ferris Wheel

62. Design a phone stand

There are lots of ways to craft a DIY phone stand, which makes this a perfect creative-thinking STEM challenge.

63. Conduct an egg drop

Put all their engineering skills to the test with an egg drop! Challenge kids to build a container from stuff they find around the house that will protect an egg from a long fall (this is especially fun to do from upper-story windows).

Learn more: Egg Drop Challenge Ideas

64. Engineer a drinking-straw roller coaster

STEM challenges are always a hit with kids. We love this one, which only requires basic supplies like drinking straws.

Learn more: Straw Roller Coaster

65. Build a solar oven

Explore the power of the sun when you build your own solar ovens and use them to cook some yummy treats. This experiment takes a little more time and effort, but the results are always impressive. The link below has complete instructions.

Learn more: Solar Oven

66. Build a Da Vinci bridge

There are plenty of bridge-building experiments out there, but this one is unique. It’s inspired by Leonardo da Vinci’s 500-year-old self-supporting wooden bridge. Learn how to build it at the link, and expand your learning by exploring more about Da Vinci himself.

Learn more: Da Vinci Bridge

67. Step through an index card

This is one easy science experiment that never fails to astonish. With carefully placed scissor cuts on an index card, you can make a loop large enough to fit a (small) human body through! Kids will be wowed as they learn about surface area.

68. Stand on a pile of paper cups

Combine physics and engineering and challenge kids to create a paper cup structure that can support their weight. This is a cool project for aspiring architects.

Learn more: Paper Cup Stack

69. Test out parachutes

Gather a variety of materials (try tissues, handkerchiefs, plastic bags, etc.) and see which ones make the best parachutes. You can also find out how they’re affected by windy days or find out which ones work in the rain.

Learn more: Parachute Drop

70. Recycle newspapers into an engineering challenge

It’s amazing how a stack of newspapers can spark such creative engineering. Challenge kids to build a tower, support a book, or even build a chair using only newspaper and tape!

Learn more: Newspaper STEM Challenge

71. Use rubber bands to sound out acoustics

Explore the ways that sound waves are affected by what’s around them using a simple rubber band “guitar.” (Kids absolutely love playing with these!)

Learn more: Rubber Band Guitar

72. Assemble a better umbrella

Challenge students to engineer the best possible umbrella from various household supplies. Encourage them to plan, draw blueprints, and test their creations using the scientific method.

Learn more: Umbrella STEM Challenge

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