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Sink or Float Experiment for Preschoolers

Last updated on October 28, 2019

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Set up a sink or float experiment  to teach toddlers and preschoolers about density and buoyancy. This play-based learning activity combines a science activity  and a water activity, and for some extra fun, we’re adding a colourful twist. 

My kids love science. Thankfully, there are tons of easy science activities that we can do at home to quench their thirst for scientific discovery. A simple sink or float activity is a great beginner science experiment that will introduce your toddlers and preschoolers to density and buoyancy .

Physics for Preschoolers

This sink or float experiment is a simple physics experiment that will encourage your child to make predictions and observations about buoyancy and density. Through their observations, they’ll learn that buoyant objects float and dense objects sink, and if they want to be true little scientists, they can even record their predictions.

Low-prep activity for indoors or out

We love to do this low-prep activity in the backyard when the weather is nice. I set up this particular sink or float experiment three days ago and the kids have set it up themselves every day since. We’ve been enjoying it on the patio so they can get as wet and wild as they like with it.

Indoors, kids can do this activity at the kitchen sink, in the bathtub or on the floor with a tub or basin filled with water.

Engage their senses with a colourful twist!

We love adding a packet of   jello powder or juice crystals to the water. Not only does this colour the water, it gives it a wonderfully fruity scent.

The kids get a thrill out of watching the water change colour, and the pop of colour and the scent have educational benefits as well : kids retain more information when more than one sense is engaged.

What you’ll need for a sink or float activity

• waterproof toys and household items (see suggested items below)
• a container to do the experiment in i.e. plastic tub, basin, pot, bucket etc.
• drinking straws (optional)
• Jello or juice crystals (optional)

Note:  If you’re doing this experiment indoors, place a plastic table cloth or some beach towels under the bin to soak up any spills.

Suggested items for a sink or float experiment:

Items that sink.

• metal utensils
• toy car/truck
• glass gemstones or marbles (not suitable for toddlers)

items that float

• stick or popsicle stick
• bathtub toys
• foam shapes
• rubber ball

How to do an educational sink or float experiment

Start off by collecting the items for your experiment. If you give your kids a list of things to collect, this  part of the activity can be a fun little scavenger hunt for your kids.

Fill a tub or bucket with lukewarm water.

If colouring your water, you can add it now or once the toys have been added.

Before adding your objects to the water, ask your children to predict which objects they think will sink and which will float.

In a classroom, this can be done by a show of hands in favour of an item sinking or floating. If you’re doing this activity with a large group, it can be fun to have a tally beside each item to indicate each child’s hypothesis.

Now, have the kids drop the objects, one by one, into the water one observe what happens.

Once all of the items are in the water, you can extend the activity by giving the kids drinking straws to blow the floating items around. This is a fun way to teach children about kinetic energy as the air they blow through the straw propels the floating items forward.

The science behind the sink or float experiment

Before explaining why items sink or float, ask your children why they think an object sinks or floats. They may guess it’s because of size or weight or construction.

Then, explain that items sink or float based on their density . Density is determined by how close or far apart molecules are within an item. Molecules are tiny and only visible by a microscope. You can refer to this article to help explain this  to your kids. I’ve also listed a few books below that you can read with your kids before doing the experiment.

You can also use this opportunity to explain why blowing through a straw moves the floating items around the bin (kinetic energy).

Once you have prompted their learning by explaining the science behind the activity, allow your children to replicate the experiment as many times as they please. This will help to solidify their knowledge and reap the benefits of play-based learning.

Since first doing our sink or float experiment, my kids have set up their own version of the activity every day since. It’s been amazing to see their fascination with such an educational activity.

More easy science activities:

Three Chemical Reactions for Kids

Water Displacement Experiment for Preschoolers

for FREE crafts, 

activities & recipes!

Reader Interactions

Lindsay Robinson

April 14, 2020 at 11:22 pm

Hi, I really enjoyed reading about your lesson. Thank you for the ideas. Where did you get the clear plastic buckets?

Jackie Currie

April 16, 2020 at 8:59 am

I’m not sure where that bucket came from, but if you search for “clear ice buckets” on Amazon, there are quite a few options there, Lindsay.

December 10, 2021 at 3:50 pm

What if, before explaining why things sink or float, you help them figure out ways to test their hypothesis? For example, if they guessed size, can they figure out what size is the cutoff? Can they find any objects that sink at a size they predict would float, or vice versa? Same with weight or whatever other theory they come up with.

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Science Projects > Physics & Engineering Projects > Learn About Sinking & Floating Objects  

Learn About Sinking & Floating Objects

All objects, including liquids, have a mass-to-volume ratio known as density. Density is a measurement for how compact (close together) the molecules in the object are.

In the first sink or float experiment, you’ll predict the density of common household objects. In the second oil in water experiment, you’ll analyze the density of common liquids.

Floatable Objects Experiment

Sink or float.

You probably already know that some things will float in water and some will not. Do you know why that is? Sometimes the best way to find out if something will sink or float is just to try it—and that is exactly what you’ll do in this “floatable objects” experiment! Gather up some objects from around your house to test their sinking or floating abilities. Make sure all of the items you pick can get wet!

What You Need:

• a large container of water (or fill up a sink or bathtub)
• lots of small objects of different weights and materials (plastic, metal, wood, foil, Styrofoam)
• a few larger objects
• HST worksheet

What You Do:

1. Look at the objects you collected. Draw a picture of each one in the boxes on the left side of the worksheet.

2. Make a prediction about each object – do you think it will sink or float in the tub of water? (To make a prediction means to say what you think will happen.) Mark your prediction on the worksheet for each item (circle float or sink).

3. Drop the objects into the water one at a time. Watch what happens to each one. Did you predict correctly? Circle “float” or “sink” next to each object on the sheet to show the results of your experiment.

What Happened:

Even though some of your items seemed very light (things like a paperclip or a button), they still sank in the water. Some objects that might have seemed sort of heavy (like a wooden block) probably floated.

That is because whether an object sinks or floats in water doesn’t just depend on its weight or size. It also depends on its density. Density is a measure of how solid something is. All things are made up of tiny particles called molecules. If the molecules inside an object are very close together, the item is solid, or dense. If the molecules are farther away from each other, the object is less dense, or less solid. An example of a very dense item is a penny. A cork is less dense.

A penny, paperclip, or button sank because the materials they are made of (metal for a paperclip and penny, plastic for a button) had more density than water. (Their molecules are closer together than water molecules are.) A cork, piece of wood, or Styrofoam floated because those materials have less density than water. All the objects that were less dense than water floated in the water! Objects that were more dense than the water sank.

Oil in Water Experiment

Liquid density.

Do you know why oil floats on water? Would an object that sinks in oil be able to float in water? Try this experiment to find out and learn more about density.

• 1-cup glass measuring cup
• vegetable oil
• food coloring
• small objects (we used a raisin, grape, cork, button, penny, screw, and piece of wax)

2. Add 1/3 cup of corn syrup so that the level of liquid in the cup rises to the 2/3 cup mark.

3. Add 1/3 cup of oil to fill the cup to the 1 cup mark.

4. Watch what happens. The layers should separate so that the corn syrup is on the bottom, the oil is on top, and the water is in the middle.

5. Guess where each of your objects will land when dropped into the cup, then test them out one at a time.

The corn syrup was the most dense liquid, so it sank to the bottom of the cup. The water was less dense than the corn syrup, but more dense than the oil, so it settled on top of the corn syrup. The oil was the least dense, so it floated on top of the water!

The objects that you dropped into the cup had different densities. Each object sank into the cup until it got to a liquid that was more dense than it. The cork was not very dense at all, so it floated on the surface of the oil. The wax fell into the oil, but not all the way to the water, so it was more dense than the cork, but not as dense as water. The grape and the raisin fell to the bottom of the water layer, but not into the corn syrup. That means that they were less dense than the corn syrup, but more dense than the water! The penny and screw were very dense; they sank all the way to the bottom of the corn syrup!

To learn more about the properties of water, check out our Science Lesson, Learn About Water .

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Sink or Float

Introduction to Sink or Float

When you drop something into water, it can either sink down to the bottom or float on the surface. Why does this happen? It’s all about density!

Every object has something called density. Density is how much stuff (mass) is packed into a certain amount of space (volume). Objects with high density sink, while those with low density float.

Sinkers and Floaters

Heavy things like rocks or metal objects have high density, so they sink. Lighter things like plastic toys or wood have lower density, so they float.

Shape Matters

Sometimes shape can affect whether something sinks or floats. Even though a ship is made of metal, its shape helps it float because it’s hollow and full of air.

Water Displacement

When something is placed in water, it pushes some of the water out of the way. If the object is heavy and dense, it pushes a lot of water, sinking it. If it’s light and less dense, it pushes less water and floats.

Experiments

You can test sink or float with different objects at home! Gather objects like coins, feathers, and toys, and predict whether they will sink or float. Drop them in a bowl of water and see what happens.

Real-World Examples

Understanding sink or float is important in many real-life situations. Engineers use this principle to design ships, submarines, and even hot air balloons!

Sink or float is a simple but fascinating concept that helps us understand how objects behave in water. Remember, it’s all about density and the amount of space an object takes up!

Download PDF

Introducing kids to science concepts can be both educational and entertaining, especially when you can do it right in the comfort of your own home! One classic science lesson that never fails to fascinate young minds is learning about sink or float. Not only is it a simple concept to grasp, but it also encourages critical thinking and experimentation. So, let’s dive in and explore how you can turn your kitchen or bathtub into a science laboratory for a day of learning and discovery!

Sink or Float: What Does It Mean?

Sink or float is a basic principle in physics that involves understanding why some objects sink in water while others float. It’s all about density! Density is the measure of how much mass (or “stuff”) is packed into a certain volume. Objects with a higher density than water will sink, while those with a lower density will float.

For kids, this concept can be demonstrated with everyday objects found around the house. Through hands-on experimentation, they can observe and understand why certain items behave the way they do in water.

Getting Started: What You’ll Need

The best part about teaching sink or float is that you likely already have everything you need right at home! Here’s what you’ll need to get started:

• A large container filled with water (a sink, bathtub, or a large bowl will work)
• Various objects from around the house (e.g., toys, fruits, coins, kitchen utensils, small household items)
• A towel for cleanup
• Paper and pen for recording observations (optional)

Exploring Sink or Float: The Experiment

Now that you’ve gathered your materials, it’s time to begin the experiment! Here’s a step-by-step guide to help you navigate through the activity:

• Start by filling your container with water. Make sure it’s deep enough to fully submerge the objects you’ll be testing.
• Encourage your child to pick up an object from the selection you’ve gathered. Ask them to make a prediction: Will it sink or float?
• Have your child gently place the object in the water and observe what happens. Did their prediction match the outcome?
• After each test, discuss the results with your child. Encourage them to think about why certain objects sink while others float. This is a great opportunity to introduce the concept of density and discuss why some objects are heavier or lighter than water.
• Continue testing different objects, allowing your child to make predictions and draw conclusions based on their observations.
• Encourage your child to record their findings if desired. They can create a simple chart or list to document which objects sank and which ones floated.

Expanding the Experiment: Further Exploration

Once your child has a good grasp of the sink or float concept, you can extend the learning experience by introducing new variables or challenges. Here are some ideas to try:

• Experiment with different liquids: Explore whether objects sink or float in liquids other than water, such as oil or vinegar. Compare the results and discuss why certain liquids have different effects on buoyancy.
• Change the temperature: Investigate whether water temperature affects an object’s ability to sink or float. Try using cold water versus warm water and observe any differences in the outcomes.
• Build a boat: Challenge your child to design and build a boat using materials like aluminum foil, plastic bottles, or craft sticks. Test their creations to see how well they float and discuss the design factors that contribute to buoyancy.
• Conduct a density experiment: Fill containers with different liquids of varying densities (e.g., saltwater, sugar water) and test how objects behave in each solution. This can help reinforce the concept of density and its role in determining whether an object sinks or floats.

Learning Through Play

Teaching kids about sink or float is a fantastic way to introduce them to basic scientific principles in a fun and engaging way. By conducting simple experiments with everyday objects, children can develop critical thinking skills, make observations, and draw conclusions—all while having a blast!

So, the next time you’re looking for a hands-on learning activity to do with your child, why not give sink or float a try? With just a few household items and a sense of curiosity, you can transform your home into a science laboratory and inspire a love of learning that will last a lifetime. Happy experimenting!

• Buoyancy Principle : The concept of sink or float is governed by Archimedes’ principle, which states that any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. This principle is fundamental in understanding why objects sink or float in different fluids.
• Density Matters : Whether an object sinks or floats depends largely on its density compared to the density of the fluid it’s placed in. If the object is denser than the fluid, it will sink. If it’s less dense, it will float.
• Shape Affects Buoyancy : The shape of an object also affects its buoyancy. For example, a ship floats because of its shape, which displaces enough water to generate an upward buoyant force greater than its weight.
• Density of Water : Pure water has a density of about 1 gram per cubic centimeter (g/cm³). Objects with a density greater than 1g/cm³ will sink in water, while those with a density less than 1g/cm³ will float.
• Density of Objects : Different materials have different densities. For example, wood generally has a lower density than water, which is why most types of wood float. Metals like iron or steel have densities greater than water, causing them to sink.
• Saltwater vs. Freshwater : The density of water can change depending on its salinity. Saltwater is denser than freshwater, which is why objects that might float in freshwater may sink in saltwater due to the increased buoyant force.
• Surface Tension : Surface tension can also affect whether an object sinks or floats. Some small, lightweight objects can float on the surface of water due to surface tension, even if their density is greater than that of water.
• Gas Bubbles : Sometimes, gas bubbles trapped within an object can affect its buoyancy. For example, some types of wood have air pockets within them, which decrease their overall density and cause them to float.
• Temperature and Pressure : Changes in temperature and pressure can affect the density of both objects and fluids, which can influence whether an object sinks or floats. For instance, cold water is denser than warm water.
• Application in Science and Engineering : Understanding the principles of sink or float is crucial in various scientific and engineering fields, such as shipbuilding, designing flotation devices, and determining the composition of materials through techniques like flotation analysis in archaeology and mineral processing.

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July 20, 2013 By Chelsey

Science for Kids: Sink or Float (with Free Printable)

Kids love discovering which items will sink or float ! It’s a great hands-on science activity for kids of any age and really gets kids thinking and predicting. Here’s how we set up our sink or float science project, as well as a free printable kids can use to record their observations.

Follow our Science for Kids Pinterest board!

This experiment was actually initiated by Lucy herself! She had approached me one day and asked if I could help get her a container of water to test out some objects she had collected.

Kids are naturally curious about floating and sinking, and this science activity provides the opportunity for children to make predictions and observations about floating and sinking with minimal help.   (This post contains affiliate links.)

Materials for Sink or Float Science:

• Large container filled with water
• Objects collected from around the house
• Free printable recording sheet  (optional)

• Walk around your house with your child and collect items you’d like to test out. (We collected these things: bristle block ,  plastic toy, crayon, cork, a spoon, and a rock.)
• Fill a large container with water. (We used a large plastic bin.)
• Find a place to conduct the science experiment where your child can easily reach the bin and where you don’t mind a bit of water possibly getting out.
• Have your child choose one object at a time.  Do you think it will sink or float? Why?   Have your child place the object in the water and observe what happens. (Optional: Record the result on the recording sheet. You can have your child draw a picture or write the name of the object or model writing and drawing the object yourself.)
• Repeat this for all the objects.
• Why do you think some objects floated and some sank? Is there anything the same about the objects that floated? How about with the objects that sank? 

Lucy had so much fun with this! It was fun to sit back and watch her excitement and curiosity grow as the activity went on. At one point she even came up with a new question, “I wonder what will happen if I push the floating things down to the bottom. Maybe they will stay there.” She discovered they still floated right back up!

• We took our experiment outside. That way there was no worry about a mess being made.
• I left this outside for a few days for the kids to experiment with on their own during play time.
• This would also be a fun center in a school classroom!

Want to go even further?

Even more activities to inspire creativity and critical thinking for various ages.

• Fill up a giant backyard pool with water and do this experiment with larger items.
• For older kids, introduce the terms density and buoyancy to explain what happened.
• Place an orange in your container of water to see if it floats. Peel the orange and try it again. What happened?
• Try the Floating Egg experiment found on Tinkerlab.
• Do our Dancing Raisin science experiment.

Find more STEM activities in our ebook! Learn more about it here , or b uy it now here !

STEM Experiment: Scientific Method Float or Sink Activity

Sharing is caring!

Oh the scientific method! Such a structured way to exploration but so helpful when taking on a big scientific project. Scientists and researchers use this method when trying to answer questions about our world. Following the scientific method allows researchers to have a guide that helps them organize all the information. Because let’s face it, nowadays the information at our fingertips is so huge! With this STEM experiment, you can help your children get an understanding of using the scientific method in a fun and educational way.

** Check out our Simple Science Project For Kids: Float or Sink for a simple play-based version of the Float or Sink experiment! Perfect for younger kids or if you are looking for a less structured activity. **

Having a tool like the scientific method is very useful. And introducing it to your kids will help them with problem-solving and analytical skills. It will give them a way to structure their thoughts when problems arise. It also shows them to take their time to think about the problem and analyze different perspectives before choosing the best solutions.

Some Background Information

The scientific method is used by scientists to structure their research and make the process of discovering something more efficient and effective.

The steps to the scientific method are the following:

As you can see, there are many steps before starting any experiment. By researching and writing down your hypothesis first you will be able to set up the perfect experiment to answer the question. You will also have some background knowledge that will help you when doing the experiment.

STEM Experiment: Let’s find out the Answer to…

The question.

So here is a question for your children:

Why do you think things float or sink?

They probably have some ideas and answers for this. Encourage them to write down their original thoughts so that you can compare them once you are done with the STEM experiment.

Here you can find a free printable to fill out as the experiment goes on.

Time to Research

Research is usually done by reading and reading and more reading of scientific papers, journals and relevant material. We are not going to do this 🙂 We will move the research along by asking our kids some questions. So let’s get your kids brain to work a bit:

• Think of objects that float/don’t float, what are they made of? How big are they?
• Do you float in water? Can you make yourself float more or less? (By filling your lungs with air and holding your breath you will float more)
• Show them a list of materials, do you think materials matter?
• Show them different sized objects or images of objects, do you think size matters?
• What other things do you think affect the ability of an object to float or sink?

Write down a Hypothesis you want to test

Now that you have brainstormed about why an object floats or not you can make a hypothesis or more than one! But first, what is a hypothesis?

• A hypothesis is an idea or explanation for something that needs to be proved
• A hypothesis tries to answer the question of your research (in this case, why do things float or sink?)
• A hypothesis is proved through experiments and testing

Some ways you can express your hypothesis:

• Things made out of _______ float/sink
• Things that are ___________ float/sink
• Floating depends on ______________

Time to test those Hypotheses

Once you’ve made a hypothesis, ask your child how you could test it. Here are a few examples of experiments you could do with them but feel free to come up with your own!

First step in any experiment is to gather the materials you are going to test and any tools you might need. For any experiment you are going to need:

• Objects to test (different sizes, materials and shape)
• Water, in a bucket, in the sink, in the bathtub, in a small outdoor pool
• Paper and pencil to write down your findings

Ways you can experiment and make your children think about the hypotheses:

• Categorize the objects you have collected and test their floating ability by pairs:

           ○ same material, different size

           ○ same material, different shape

           ○ same size, different weight

• Get plastic containers and fill them with different materials and test the floating capabilities, for example:

          ○ empty container

          ○ container filled with cotton (what happens when cotton gets wet?)

          ○ container filled with sand

          ○ container filled with water

          ○ container filled with sticks

          ○ container filled with coins

          ○ container filled with stones

• Do the same with a glass container

There is a list of materials and object ideas in the guide for inspiration. Let them experiment and play 🙂 there is no rush to finish the activity! Don’t forget to write down your findings so you can analyze them later!

Let’s analyze those Resultats

Now it’s time to look back on your STEM experiment and the results to see if your hypothesis was correct. You can ask the hypothesis back in question form and see if the results support it! Other questions you can ask to discover why certain objects float:

• Does wood/plastic/metal/stone float?
• Does shape or weight matter?
• What containers could float? Which ones would sink? What was inside of them?

Conclusion Time

So did you find out why things float? Did you test your hypothesis? Did you get some fun ideas about other things you could test with this method? Did more questions pop up as you experimented? Welcome to the STEM world! The questions never end 🙂 and this is oh so important for your children to experience. How to answer questions using the scientific method is a must in the STEM world. If you want a more detailed answer to why things float you can download the printable guide, there is an explanation at the end. But I’m sure that you will have a pretty good idea about the answer from all that scientific experimenting you will do 😉

So to finish up the activity you can talk about what you discovered and if there are more things you would like to research together. If you have any topics you would like me to cover just comment below and I’d be happy to write a post about it in the future. I hope you enjoyed this activity and had fun experimenting and discovering how our world works.

For more information about STEM and how to transform your STEM activities at home, check out these posts:

• 5 tips to transform STEM activities at home
• What is STEM and why is STEM learning important?

Check out other fun STEM activities to sneak in some STEM learning:

• STEM activity: Build a pyramid and learn about shapes
• STEM project: Engineer a house out of natural materials
• STEM challenge: The Tower of Random Things
• STEM water play: 8 fun activities to try this summer
• STEM Road Trip Experiment

Happy STEM learning!

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Easy Sink or Float Experiment For Kids

Open the fridge and pantry drawers for this sink or float experiment. You have everything you need to test whether objects sink or float in the water with common household items. Plus, grab the free printable worksheets to add to extend the activity.

Sink or Float Experiment

We used items from the kitchen for our sink and float experiment. Plus, I am sure your child will be able to come with other fun things to test! You can even have them test a collection of their favorite items, too!

Watch the Video:

💡Read all about the science below! Take a look at more experiments you can do here!

• a large container filled with water
• different fruits and vegetables
• aluminum foil
• aluminum cans
• spoons (both plastic and metal)
• anything your kiddos want to explore
• free printable worksheets (see below)

💡 Tip: You could also try peeling or slicing your vegetables. 

Instructions:

STEP 1. Before you start, have your kiddos predict whether the item will sink or float before placing the object in the water.

STEP 2. Place each object in the water one by one and observe whether it sinks or floats.

If the object floats, it will rest on the water’s surface. If it sinks, it will fall beneath the surface. Read the science info below about why some objects float and some sink.

Extension: Does Aluminum Sink or Float?

The aluminum can, and aluminum foil were some exciting things we tested in our sink or float activity . We noticed the empty can could float, but it would sink when pushed under the water. Also, we could see the air bubbles that helped it float. Have you seen the crushing cans experiment?

Project: Does a full can of soda float, too? Just because something feels heavy doesn’t mean it will sink!

The aluminum foil floats when it is a flat sheet when it is crippled into a loose ball, and even a tight ball. However, if you give it an excellent pound to flatten it, you can make it sink. Removing the air will sink it. Check out this buoyancy activity with tin foil here!

Project: Can you make a marshmallow sink? We tried it with a Peep candy. See it here. What about a paper clip? Check out this experiment here.

Why Do Objects Sink or Float?

Some objects sink, and some objects float, but why is that? The reason is density and buoyancy!

Every state of matter, liquid, solid, and gas, has a different density. All states of matter are made up of molecules, and density is how tightly those molecules are packed together, but it’s not just about weight or size!

Items with molecules packed tighter together will sink, while items made up of molecules that are not as tightly packed together will float. Just because an item is considered a solid doesn’t mean it will sink.

For example, a piece of balsa wood or even a plastic fork. Both are considered “solids,” but both will float. The molecules in either item are not packed together as tightly as a metal fork, which will sink. Give it a try!

If the object is denser than water, it will sink. If it’s less dense, it will float!

Check out more easy density experiments.

Buoyancy is the ability of an object to float or rise in a fluid, such as water or air. It occurs because the upward force exerted by the fluid (liquid or gas) is greater than the downward force of gravity acting on the object.

In simpler terms, buoyancy is how well something floats. Generally, the greater the surface area, the better the buoyancy. You can see this in action with our tin foil boats !

In our sink or float experiment below the vegetables that float are buoyant because the upward force of the water is greater than their weight, helping them stay on the water’s surface. Those that sink are denser than water.

TIP: Discuss how some vegetables might have air pockets inside them, contributing to their buoyancy.

Try This: Do Vegetables Sink or Float?

Generally, fruits and vegetables with higher water content are more likely to float, while those with lower water content or denser structures may sink. Here are some examples:

Fruits and Vegetables That Tend to Float:

These fruits and vegetables have a higher water content and often contain air pockets, making them less dense than water and more likely to float.

Fruits and Vegetables That Tend to Sink:

• Sweet potatoes
• Avocado (when submerged)
• Winter squash

These fruits and vegetables are denser and have less water content, making them more likely to sink in water.

It’s important to note that there can be variations within each type of fruit or vegetable, and factors such as size, ripeness, and the presence of air pockets can influence whether they float or sink. Conducting a simple sink or float experiment with a variety of fruits and vegetables can be a great way to explore these ideas further.

Free Printable Sink or Float Worksheets!

Grab our free sink or float printable worksheets for kids to record their observations! Find more [here] .

More Fun Water Experiments

Check out our list of science experiments for Jr Scientists!

• Walking Water Experiment
• What Materials Absorb Water?
• What Dissolves In Water?
• Saltwater Density Experiment
• Do Oranges Sink or Float?
• Freezing Water

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!

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• 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!!
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Wonderful idea and great way to kick start our science week in the little room. But the free printable is not there anymore. Is the link broken?

Hi Emily, thank you! It is there towards the bottom of the page. It is possible that your organization is blocking the link. Feel free to email me [email protected]

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• For Teachers

• Everyday Activities
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Sink or Float

This easy science activity can be done anywhere you can put a container of water. Try it in your backyard, the bathtub, or the kitchen sink!

• Indoor or Outdoor

Activity adapted from PBS Kids for Parents .

You Will Need

A container for water (a clear container works best)

A collection of 6-12 items to test if they sink or float

• Have your kids collect the items they want to experiment with. This could be bits of nature such as pine cones, grass, flowers, sticks, rocks, shells, etc. Or items from around the house such as small toys, crayons, pencils, a ball of aluminum foil, paper clips, blocks, metal spoon, apples, anything! (If you give your kids a list of items to collect, it could be a fun scavenger hunt for them to enjoy while you get the other items set up!)
• Ask your child to predict which items they think will sink, and which items they think will float. Write down their predictions on the paper. Ask them why they sorted the items the way they did.
• Test your predictions! Drop each item into the water to see what happens.
• Were the predictions correct? Why or why not? Note your observations on the paper.
• Sort the items again based which items actually sank or floated. Talk about the features that were common about the items in each category.

How it works

All objects are made up of teeny tiny molecules. Objects with tightly packed molecules (like rocks) are more dense than objects with loosely packed molecules (like a leaf.) Density is a measure of how compact the molecules of an object are. Objects that are more dense than water will sink, and objects that are less dense than water will float.

Most young scientists guess that items will sink or float based on their size or weight. Did any small items sink that kids predicted would float? A common example of this is a pebble or a marble. Pebbles and marbles are very small but also very dense, so they actually sink when many young scientists predict they will float.

Did you experiment with any large objects that are filled with air? Air is less dense than water, so large hollow objects, like a basketball, float! (This is also partially how enormous ships float.)

The shape of the object is another thing to consider. Did you observe anything about the shape of the items that sunk? Generally, the more surface area of an object that touches the water, the more likely it is to float. This is called buoyancy. The object is pushing down on the water, and the water is pushing up on the object. (You can demonstrate buoyancy with a piece of aluminum foil. First, lay the foil out flat on top of the water - it will float. Then ask your young scientist to crush the foil into a tight ball, and try it again. This time, it should sink! How can this be? It is the same piece of foil! The reason is the amount of surface area that is touching the water - the more surface area it has to touch the water, the more likely it is to float!)

NOTIFICATIONS

Building science concepts: floating and sinking.

• + Create new collection

Floating and sinking provides opportunities for students to observe how everyday objects behave in water and to investigate the factors that determine whether an object will float or sink.

The New Zealand Ministry of Education’s Building Science Concepts (BSC) series presents sets of interlinking concepts that build stage by stage towards big ideas in science. A big idea shows how a fully developed understanding of the concept might look, but recognises that such an understanding might not be achieved until New Zealand Curriculum level 7 or 8.

This resource is a partial replicatio n of Building Science Concepts Book 37 Floating and Sinking: How Objects Behave in Water . It covers the science notes provided in the original BSC book. The overarching science concepts (big ideas) and how they may be scaffolded in sequence are illustrated in the image below.

Introduction

This resource is designed to build on students’ experiences with water and their observations of everyday objects floating or sinking.

This resource also links to Building Science Concept Book 38 Understanding Buoyancy: Why Objects Float or Sink .

The themes covered in BSC Books 37 and 38 include:

• how everyday objects behave when they are put into water
• why objects float or sink
• density, volume and displacement.

Floating and sinking

We tend to think of objects as floating or sinking but objects can show varying degrees of buoyancy. An apple may float half in the water and half above, while an empty, sealed plastic bottle might bob on the surface of the water.

We need to think about three elements .

• The whole system – for example, a boat and a life jacket float and a person may sink, but a person-in-a-boat system or a person-wearing-a-lifejacket system both float.
• Whether the system is supported by water – for example, the bobbing apple is supported by water so it is floating.
• The situation at that moment – for example, a stone skimmed across the water’s surface floats while it is moving but sinks as it loses speed.

Forces acting on an object – why does an object float or not?

Three factors affect whether an object floats or sinks.

The volume of an object

The volume of an object is important in determining whether it will float, as the upthrust force of the water is equal to the weight of this displaced water, and the amount displaced is determined by the volume.

If changing the shape of an object that sinks increases its volume, the object will displace a greater volume of water. This displaced water tends to return to its original position and, in doing so, exerts a force on the object known as the upthrust. More water displaced equals more upthrust. For floating to occur, this upthrust needs to be equal or greater than the force of gravity operating on the object.

For example, a ball of modelling clay will sink, but if you shape the ball into a boat shape, the clay will float. The boat shape has a larger volume, which displaces more water than the ball shape, until the upthrust equals the boat’s weight. Another way of viewing this concept is that the boat shape floats because it holds air and so the boat+air system is less dense than the water.

Density of an object

The density of an object is the relationship between its mass and its volume. Density refers to how tightly packed the particles of an object or system are. A dinghy containing three people might float easily – for its volume, the boat contains relatively little mass. But if an additional 10 people step onto the dinghy, the mass has increased to the point where the overall density of the dinghy+people system becomes more than the density of the water it is displacing, and it begins to sink. The force of gravity, due to the extra weight, pulls the dinghy and its occupants downwards. The force of gravity has become greater than the upthrust of the water on the boat’s surface.

Alternative conceptions

These are some alternative conceptions that students may hold:

• The size of an object determines whether it floats or sinks – small objects float and large objects sink.
• The weight of an object determines whether it floats or sinks – light objects float and heavy objects sink.
• Soft objects are more likely to float than hard objects.
• Objects that float have air inside them.
• Floating objects must sit wholly above the surface of the liquid.
• If two objects weigh the same, they will both float or both sink.

Younger students may equate the smallness and lightness of an object with its ability to float. They are less likely to consider the object’s volume in terms of how much water it displaces.

If volume is the only factor considered, students may think that objects of the same density but different size/rahi – for example, small and large pieces of candle – will behave differently. They may expect the small pieces to float and the large pieces to sink, whereas pieces of all sizes will float because they all have the same density, which is less than that of water.

Related content

Use these articles to further explore aspects of floating and sinking.

• Water density
• Ocean density
• Ocean salinity

Use these images to gather students’ ideas about floating and sinking.

• Floating ice
• Floating icebergs
• Tip of the iceberg

Our Floating and sinking Pinterest board is full of related resources.

Literacy resources

A sinking feeling is a title from the Connected serie s and introduces the concepts that underpin floating and sinking in the context of a boat race. The teacher support materials provide curriculum links and include suggestions on how the article can be used to grow science capability in critiquing evidence.

Activity ideas

Will this float or sink? uses an interactive or paper-based graphic organiser to consider whether an object floats or sinks. Use it prior to a unit on floating and sinking to gauge students’ thinking and again during and after the unit as formative assessment.

Investigating floating and sinking is a set of activities that use play and exploration to directly observe how everyday objects behave in water.

Floating and sinking – exploring forces use play and exploration to explore the support force (upthrust) that keeps objects afloat.

Temperature, salinity and water density – use this activity to help your students visualise differences in water density.

Floating eggs – students investigate water density by floating an egg in freshwater and saltwater.

Buoyancy in water – students make a Cartesian diver to demonstrate the relationship between volume, mass and density.

Investigating seawater – students investigate some of the properties of seawater.

The Tip of the iceberg image shows how ice floats in salty seawater. Place an ice cube in a glass of water and observe if it floats in the same manner.

Useful links

Related building science concepts books.

• Understanding Buoyancy: Why Objects Float or Sink (Book 38) – explores floating and sinking including in other media. This is aimed at levels 3–4.
• Parachutes: Floating and Falling in Air (Book 34) – extends the investigation of floating and sinking to the medium of air.
• Where’s the Water?: Water’s Forms and Changes in Form (Book 15) – investigates the three states of water and the processes of evaporation and condensation.
• Ice: Melting and Freezing (Book 37) – focuses on the properties that characterise liquid water and solid water (ice) and the conversion between these two states.

Additional information and activities on this topic can be found in the chapter ‘Gravity and Flotation’ in Making Better Sense of the Physical World (Ministry of Education, 1999).

Assessment Resource Banks

The Assessment Resource Banks (ARBs) also offer a range of levelled activities that are ready for use in the class . You need to be registered to use ARB resources.

• Which will float?
• Will jars float or sink?
• Will it float?

Acknowledgement

This resource is a partial replication of the New Zealand Ministry of Education’s Building Science Concepts Book 37 Floating and Sinking: How Objects Behave in Water .

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Why do things float in water?

February 1, 2021 By Emma Vanstone Leave a Comment

This activity uses a bit of science trickery to make an object that sinks in water, float in water.

Objects are made up of very tiny molecules. Molecules can be packed in close together like in a rock or more spread out like in bubble wrap. The positioning of molecules affects the density of an object. Objects with tightly packed molecules are more dense than those where the molecules are spread out.

Density plays a part in why some things float and some sink. Objects that are more dense than water sink and those less dense float.

Hollow things often float too as air is less dense than water. This is partly why huge heavy ships float. Another thing to consider is the shape of an object.  Generally the more of the outside of an object that is touching the water the more buoyant it is. Water pushes back up against objects so the more surface area an object has the more water pushes back against it helping it to float.

When an object floats, it pushes water out of the way ( displacement ). Have you ever noticed that when you climb into a bath the water level rises? That’s because your body displaces ( moves ) the water.

This easy activity demonstrates how reducing the density of a heavy object allows it to float .

You’ll need:

A selection of different balls, one should sink in water

Bubble wrap

A container filled with water

Balls to use:

• Ping pong ball
• Tennis Ball
• Hockey Ball

Instructions

First sort the balls into balls you think will float on water and balls you think will sink.

Do the balls which float all have something in common? Are they hollow?

Test each ball to see if your predictions are correct.

Take a ball which sank to the bottom of your container and wrap in bubble wrap.

Place the bubble wrapped ball on the surface of the water, you should find it now floats. If it doesn’t add some more bubble wrap.

Why does this happen?

Although the bubble wrap makes the ball weigh a little more, it also displaces extra water making the ball more buoyant.

The pockets of air in the bubble wrap mean that the ball and bubble wrap together are less dense than the water, which means the ball floats!

Extension Task

What’s the smallest amount of bubble wrap you can use to make your ball float?

Using the knowledge you’ve gained from this activity, how would you make a lemon sink ?

Can you think of a different way to make the ball float? What if you made it a boat with plasticine?

Does the same technique work with other objects?

More sinking and floating activity ideas

Babble Dabble Do has a fabulous ship building activity to demonstrate how displacement helps objects float.

Can you make a superhero float ? We made out superhero arm bands and a raft,

Rainy Day Mum has a lovely activity using boats made from pie tins .

Try a  p irate themed sink and float investigation.

Find out how many coins it takes to sink a foil boat .

Learn about density with this easy investigation, can you find something to float on each layer?

Instead of making an object less dense by adding bubble wrap, try changing the density of water to help an object float.

Last Updated on February 1, 2021 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.

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Floaters and Sinkers

Activity length, 8 activities, activity type.

Density can sometimes be a tricky concept for students to understand. You can't easily estimate an object's density by simply looking at it. You have to think about the relationship between two of its properties: mass and volume.

In these activities, students will learn about mass , volume and density and their relationship to each other by conducting investigations into buoyancy : floating (and sinking) objects used in their everyday lives.

LIST OF ACTIVITIES

Dense, Denser, Densest! Up or Down? Three-Layer Float Density Mystery Bean Buoyancy Floating Rock/Sinking Wood Cola vs. Diet Cola Build a Better Bag Boat

Demonstrate how the distribution of molecules in a substance determines its density.

Investigate the relative densities of liquids and the relative densities of solids.

Predict, test and explain relative density by investigating the interactions of liquids and solids.

Demonstrate understanding of the relationship between density and buoyancy by building a boat.

see individual activities for materials.

Density, Mass & Volume Simply put, density is how tightly “stuff” is packed into a defined space.

For example, a suitcase jam-packed with clothes and souvenirs has a high density, while the same suitcase containing two pairs of underwear has low density. Size-wise, both suitcases look the same, but their density depends on the relationship between their mass and volume. Mass is the amount of matter in an object. Volume is the amount of space that an object takes up in three dimensions.

Density is calculated using the following equation: Density = mass/volume or D = m/v.

Less Dense, More Dense If something is heavy for its size, it has a high density. If an object is light for its size it has a low density.

A pebble is heavy for its size, compared to a piece of popcorn which is light for it’s size.  Imagine a big bowl of popcorn, compared to a big bowl of pebbles, which would feel heavier?

It is easy to estimate relative densities if you keep either the volume or the mass of two objects the same.

If you filled one bag with a kg of feathers and another with a kg of lead you would see that the feathers take up much more room, even though both bags have the same mass. This because feathers are less dense, they have less mass per volume. If you made a copper cube and an aluminum cube of the same volume and placed one in each hand, you would be able to feel that the copper cube would be heavier. Copper has more mass per volume than aluminum.

How can one substance have more mass per volume than another? There are a few possibilities:

• Atoms of one substance might be a similar size yet have more mass than the atoms of another substance.
• Atoms of one substance might be a similar mass but be smaller, so more of them fit within the same volume.
• Atoms of one substance might be arranged in a way that allows more of them to fit in the same volume.

Any one or a combination of these explanations could be the reason why one substance has a higher density than another. In the case of copper and aluminum, their atoms are arranged similarly, but copper atoms are smaller and have more mass than aluminum atoms, giving it a higher density.

Density, Sinking and Floating Why do some things float, while others sink? You might expect heavier objects to sink and lighter ones to float, but sometimes the opposite is true. The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it’s in will sink. An object that has a lower density than the liquid it’s in will float.

Sinking and floating applies to liquids too. For example, if you add vegetable oil to water, the oil floats on top of the water because the oil has a lower density than the water.

Buoyancy and Archimedes’ Principle The ancient Greek philosopher Archimedes found that when an object is submerged in water, it pushes aside (or displaces) an amount of water with the same mass as the object.

The water pushes upward against the object with a force (buoyancy) equal to the weight of water that is displaced.

A litre of water has a density of 1 kilogram per litre (1 kg/L), so a bowling ball’s worth of water (4.5 L) can push back on the bowling ball with a force equal to 45 newtons (N). That’s the weight of a 4.5 kg mass. However, the weight of the ball is more like 55 N. That’s more than the buoyant force of the water it displaced, so it sinks.

A beach ball may have the same volume as a bowling ball, but it has a much smaller mass. When you a beach ball in a tub of water, it displaces the mass of water equal to its own mass—about 0.01 kg. If you were to try to push the beach ball down and displace more water, the water would push back with a force greater than the weight of the beach ball. The push of the water keeps the beach ball afloat.

Buoyancy is the upward force we need from the water to stay afloat. Buoyant forces are why we feel so much lighter when we are in a swimming pool. Our bodies are mostly water, so our density is fairly close to that of water. Because of this, an average person needs only a little bit extra buoyancy to float. A life jacket provides this extra lift.

Changing Density You can change the density of a substance by heating it, cooling it, or by adding something to it. If an object sinks in water, it’s because the object has a higher density than the water. There are two possible ways to make that object float, however:

• Increase the density of the water so that the water becomes denser than the object. For example, an egg will usually sink in a glass of water, because it is denser than water. Adding salt to the water increases the density of the water, allowing the egg to float. This experiment also works with people, but you need a lot of salt (try the ocean, or even better, the Dead Sea !)

Archimedes : Greek mathematician, physicist, engineer, inventor and astronomer (c. 287 BC–c. 212 BC). Archimedes’ principle : Any object wholly or partially immersed in a fluid is buoyed by a force equal to the weight of the fluid that is displaced by the object. In other words, the buoyancy is equal to the weight of the displaced fluid. buoyancy : The upward force that a fluid exerts on an object less dense than itself; the ability to float. density : How closely packed together the molecules of an object or substance are. displace : To push out of the way. For example, when an object goes into water, it displaces the water. immiscible : Unable to be mixed together, like oil and water. ironwood : The name for a large number of woods that have a reputation for hardness and high density. mass : The amount of matter in a given space. matter : The substance that makes up all physical things. pumice stone : Lava froth known for its small mass and low density, despite looking like a rock. weight : A measure of the force of gravity on an object. volume : The amount of space a substance or object takes up.

Other Resources

BrainPOP | Science | Matter & Chemistry | Measuring Matter

EDinformatics | Mass, Volume, Density

WatchKnowLearn.org | Buoyancy and Density

ProTeacher Collection | Density

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Things That Float or Sink in Water

Identifying things that float or sink in water is a common science assignment. The project is straightforward enough for young children, but predicting whether a substance or object floats can become complicated because it involves both the density of the material and the buoyancy of an object. For example, ice floats on water. Steel is dense, so it typically sinks, yet ships made of steel sail on the seas every day.

Here is a list of substances that float or sink on water, based on density, and a look a how buoyancy lets even dense materials float.

List of Things That Float or Sink on Water (Density)

Density is the mass per unit of volume of a substance. The more mass there is in a volume, the higher the density. The density of water is about 1 gram per milliliter (g/ml) or 1 gram per cubic centimeter (g/cm 3 ). So, things that are less dense than water float on it, while substances that are more dense than water sink in it. For numerical values, consult a list of densities of common substances . Otherwise, the list of things that float are all materials with a density less than 1 g/ml, while the list of things that sink all have a density greater than 1 g/ml.

List of Things That Float

• All gases : Air, oxygen, hydrogen, nitrogen, carbon dioxide and other gases float on water. Even the densest gas, tungsten hexafluoride, has a density of 0.0124 g/ml and floats on water.
• Lithium metal
• Sodium metal
• Rotten eggs

List of Things That Sink

• Dishwashing liquid
• Heavy water
• Heavy water ice cubes
• Magnesium metal
• Aluminum foil
• A black hole

Does Poop Float or Sink?

Human feces (poop) either sink or float, depending on a few different factors. Mostly, poop is denser than water and sinks. However, it floats if a person’s diet is high in fiber or the stool contains a lot of gas or fat. While not necessarily indicative of a medical condition, floating poop can be indicative of an infection, pancreatitis, or irritable bowel syndrome.

Even a dense object floats its shape gives it buoyancy. Buoyancy is the upward force exerted on an object submerged in a fluid (liquid or gas) that opposes the weight of the object. This force is due to the pressure difference between the top and bottom of the object, which creates a net upward force.

According to Archimedes’ principle, the buoyant force on an object equals the weight of the fluid displaced by the object. If the weight of the fluid displaced is greater than the weight of the object, the object floats. If the weight of the fluid displaced is less than the weight of the object, the object sinks.

Note that it does not matter how much water is below an object (assuming it is not touching the bottom). An object floats equally well in shallow water as in deep water. Also note that adding more weight to a floating object changes the balance of forces. So, if you pile enough mass onto a floating object, it eventually sinks.

A good example of a dense object that floats is a metal ship. Despite being much heavier than water, steel cargo ships and tankers float because the shape of the hull displaces a large volume of water, creating a buoyant force that supports their weight.

Prove It For Yourself

While it’s counterintuitive that heavy objects float if they displace enough water, it’s easy to prove it for yourself. Take a sheet of aluminum foil and crush it tightly into a ball. It sinks if you throw it into a bucket of water because aluminum is more dense than water. But, if you fold up the edges of a sheet of foil to form a makeshift boat, the aluminum floats.

Common Misconceptions About Floating

There are several common misconceptions about how floating works. The following statements are false:

• Light objects float and heavy objects sink, regardless of their size or shape.
• A floating object is completely above the surface of the liquid.
• Objects only float because they contain trapped air.
• Objects float better in deep water than in shallow water.
• Bolz, Ray E.; Tuve, George L., eds. (1970). “§1.3 Solids—Metals: Table 1-59 Metals and Alloys—Miscellaneous Properties”. CRC Handbook of tables for Applied Engineering Science (2nd ed.). CRC Press. ISBN 9781315214092.
• Lima, Fábio M. S. (2014). “A downward buoyant force experiment”. Revista Brasileira de Ensino de Fisica . 36 (2): 2309. doi: 10.1590/S1806-11172014000200009
• OECD (2012). “Test No. 109: Density of Liquids and Solids”. OECD Guidelines for the Testing of Chemicals , Section 1. ISBN 9789264123298. doi: 10.1787/9789264123298-en
• Serway, Raymond; Jewett, John (2005). Principles of Physics: A Calculus-Based Text . Cengage Learning. ISBN 0-534-49143-X.

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Sink or float experiment

Explore density and buoyancy with this super simple sink or float experiment for kids. It’s exactly what it sounds like: Simply gather testable materials and a tub of water and test whether an object floats or sinks!

Preschool activities can be super engaging, can offer learning opportunities, and be super simple too. Small children can be introduced to the scientific method of researching, hypothesizing, experimenting, analyzing, and concluding through this simple sink or float activity. See what we tested below!

What is a sink or float experiment?

This is an excellent activity for young scientists – Especially those who love playing outside! Learn why we think science for kids is so important in this post.

This activity is a very simple and visual way to teach children about the scientific concepts of density and buoyancy. Depending on the age of your children or students, you’ll want to modify the science language you use. In preschool, I would ask “do you think your object will sink or float?” and “why do you think this object will float?”

For older kids, you can begin talking about density and buoyancy as well as deeper hypothesizing and analyzing. What makes an object buoyant? How can you predict the density of one object compared to the next? Etc.

Download these worksheets before starting!

This is a great standalone activity. Your little ones will learn without writing things down. But, if you want a worksheet to supplement it, you can download my Float or sink experiment worksheet from my Teachers Pay Teachers store for free. Or, if you just want to focus on learning the scientific method, I have my Scientific Method   worksheet listed there for free too.

You can also download the first one from the PDF below.

Creating the sink or float experiment: What you’ll need

This is meant to be a child-led activity, so the materials needed will vary from one kiddo to the next. Just make sure the items are safe and that they’re allowed to be tested (unlike your cell phone or favorite watch, for example).

Here is what you will need:

• You could also use the kitchen sink
• Whatever objects your children would like to test (we used a flower, a rock, a stick, a leaf, and a pinecone)

How to create the sink or float experiment

This is one of my most simple science experiments. All your kids have to do is this: Collect materials to test, hypothesize (make an educated guess) about which will float and which will sink, and then test one item at a time!

This is a fun way to encourage your children to be involved in the scientific process as they gather materials, practice testing ideas, and share their observations as they tell you which things sink and which things float.

Extended learning: Sink or float science

A simple extension to this is to challenge your little scientists to build the strongest aluminum foil boat that they can. Then, once it’s built, fill a container with water, place the boat on the water, and see how many pennies or marbles (or whatever other items you have a surplus of) you can stack on the boat before it starts sinking.

We hope you enjoy this really easy sink or float experiment! It’s the perfect science activity for a sunny day (or as an indoor activity – but keep a mop close!). Extend learning by asking kids to write or draw what they discovered. For a math component, you could do some graphing with the results, too.

Other experiments you could try

We’ve been conducting lots of science experiments lately! Here are some you might want to check out:

• What melts ice the fastest? 3 STEM activities for kids
• Which color absorbs the most heat?
• Ice insulation STEM challenge

More science posts

Searching for more science experiments and science-related activities to do with your little ones? Check out this category to see all of our posts about science for kids!

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Sink or Float Science Experiment For Kids

What items sink and which items float? Can a magnet work under water? Let’s find out the answers! We had fun exploring objects that sink or float for my 5 year old’s science lesson. I made a simple worksheet with 4 columns: object, prediction, sink, and float. He completed the prediction by writing a simple S or F before he put the object in the water. After he placed each object in the water, he would check off the actual answer. Some objects we used were a popsicle stick, a straw, a lego, a boat, a mini wrench , a nerf foam, a coin, a car, and a plane. After all the objects were in the water, he took a magnetic wand and sure enough, it was able to pick up the objects that were also magnetic! Such a fun activity for him!

Tray (we bought this drip pan at the dollar store)

Various items that will float (ie: toy boat)

Various items that will sink (ie: mini wrench tool)

Items that are magnetic (paper clip, magnetic balls, etc.)

Items that are not magnetic (straw, popsicle stick, etc.)

Sheet of paper to record observations (label sheet with hypothesis; sink, float, magnetic, non magnetic), and conclusion.

Directions:

1: Gather all magnetic and non-magnetic items.

2: Fill the tray with water. If you are recording your observations, look at each item and record if you think it will sink/float/is magnetic/is non-magnetic.

3: Add the items one by one and observe if they sink or float. Write down your observations if you are recording them.

4:After all the objects are added, use the magnetic wand to see if the object has magnetic characteristics. Record your observations.

Check out our video below!

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Lesson Plan

Sink or float, view aligned standards, learning objectives.

• Students will work in small groups to test whether objects sink or float and describe their findings orally.

Introduction

• Gather students in a group and tell them that they will be learning about sinking and floating.
• Show them a tub filled with water and the objects that will be tested.
• Define sink as the action of an object when it becomes submerged in a liquid. Define float as the action of an object when it sits on the surface of a liquid.

The Inspired Teaching Approach

What floats what sinks.

The following activity is part of a series we’re creating to support students, teachers, and caregivers, during this unprecedented time. Read more about the project  here . If you try this activity with your student(s), we’d love to see what you do. Share your journey via the  #Inspired2Learn  hashtag on your preferred social platform. 

Created by: Jenna Fournel Discipline: Science Age level: preK – upper elementary/middle Time: 30 minutes to half an hour depending on how many objects you use and how many steps you have your student(s) take. Materials: A sink or tub filled with water, about 20 different objects that you don’t mind getting wet, tape, tinfoil, plastic wrap, rubber bands and any other readily available materials that could be used to make an object sink or float. Writing materials. 

What to do:  

This activity can be as simple as sticking things in water to see if they sink and as complicated as building contraptions to make things that normally sink stay afloat (or make things that normally stay afloat sink). Depending on your timing and your student’s interest, you can do all these steps or just a few. Note that if you have a student who isn’t writing yet, you can still do this activity and write their observations on a chart for them. (If you’re a teacher using this activity for virtual learning, parents or guardians can share the writing they do with you via photos they send via email.)

• Student divides a piece of paper into four columns labeled as follows: Object Name / Hypothesis: Will it sink or float? / Test: Did it sink or float? / Why did it sink or float? How could I make it do the opposite? 
• Student lists all the objects and writes their hypothesis for each. 
• Students test each object in the sink or bath, writing the results of their test in that column. (If you are a teacher using this activity virtually you can create a collaborative spreadsheet in google docs, invite all students to that spreadsheet, and have them enter their findings in there so they can learn from one another.) 
• Next challenge students to experiment with using different materials to make objects do the opposite of what they normally do in water (i.e. using tin foil to construct a boat that will keep a heavy object afloat).
• After these various experiments, discuss the findings with your student(s). Examples of questions might be: What do you notice about all the things that floated or the things you created to help objects float? What do they have in common? What about the things that sink? If you had to build a boat, what did you learn today that you’d use to help you build it? 

Inspired Teaching Connection

This fun and sometimes unexpected approach to thinking like a scientist engaged students in the Wonder-Experiment-Learn Cycle. The activity encourages not only purpose, persistence, and action, it also generates some interesting evidence of student learning. The chart created as students test their hypotheses helps you see their learning in action. And it helps the students see their own learning, and the learning of their peers. The discussion at the end helps to check for understanding. When they devise ways to make objects do the opposite of their original nature, they’re putting their intellect, inquiry, and imagination to work! 

See our instructional model here . 

Elizabeth Cutler

Grants manager.

As Grants Manager, Elizabeth manages Inspired Teaching’s grant requirements and writes proposals and other fundraising materials. She is a writer, creative producer, and longtime improv performer and teacher. 

Elizabeth has an MA in Democracy & Governance from Georgetown University and BA in Politics from Occidental College. She previously served on the boards of nonprofits Young Professionals in Foreign Policy and the District Improv Festival.

What brings you joy in life?

Creativity! Pushing through a challenging writing process or learning a new improv format often feels frustrating at the moment, but the satisfaction of reaching the other side brings me such joy. I also love seeing a variety of live theater and performances and nerding out about books. 

Dr. Michelle Edwards

Director; founder & ceo, the idari collective.

Dr. Edwards is the Founder and CEO of the Idari Collective. Idari means leadership in the Yoruba language. The Idari Collective is a coaching, mentoring, and consulting firm whose mission is to come alongside leaders, especially Black women leaders, so that they will thrive in leading their personal and professional lives. 

She is a native Chicagoan and a career educator who found her way to the East Coast as a resident principal in New Leaders, Inc. during its inaugural year in Washington DC. She also served as a principal in Anacostia at Orr Elementary for almost a decade. Michelle returned to New Leaders in 2013 as the Director of the Emerging Leaders Program. Dr. Edwards served for nearly seven years as the Executive Director at Live It Learn It, an experiential learning nonprofit located in Washington, DC that partners with schools and cultural institutions to create and deliver experiential learning opportunities for Black and Brown elementary-aged students. 

She earned a Doctorate in Educational Leadership from the University of Pennsylvania and received a Certificate in Executive Nonprofit Management from Georgetown University. Michelle is a graduate of Creative Results Management, where she was trained to coach. Dr. Edwards also advocates for social justice and racial reconciliation as a leader of the DC Unity and Justice Fellowship, a new 501c3 in Washington, DC where she serves as the inaugural Board Chair. She is a trained Urban Missionary, a proud, 25+ year-member of Delta Sigma Theta Sorority, Inc., and the mother of two adult sons, Darren and Dante.

Meag Campos

Project manager.

Micaiah Anderson

Community outreach specialist.

As a Community Outreach Specialist, Micaiah is responsible for program promotion and outreach support for Inspired Teaching events and workshops. Micaiah has a passion for collaborating with community members to build-power and connect. She is an educator with a heart for youth and has experience supporting students fight injustices within their schools and communities. She has a BA in Political Science from, the real HU, Hampton University & anticipates graduating in May 2024 with a Masters of Arts degree in Educational Policy Transformation from Georgetown University. 

" I want to have a say in what happens to me."

Autonomy is the need for independence; the ability to make choices, to create, to explore, and to express oneself freely; to have sufficient space, to move around, and to feel unrestricted with opportunities to exercise free will.

Brady Maiden

Speak truth faculty.

As Speak Truth Faculty, Brady helps to lead one of our model youth programs. She provides training and support to high school students as they lead and engage in Speak Truth discussions on issues important in their lives. Brady has her Master’s in Public Policy from George Mason University and her BS in Political Science from Northern Arizona University. She is passionate about community, equity, and coalition building recognizing that learning and growing with the community at large is how we continue to be impactful.

I find joy in spending time with my friends and family and meeting new people. I like going to concerts and festivals, and finding new books to read. 

The Learner’s Cycle, Wonder-Experiment-Learn , and the Teacher’s Cycle, Observe-Plan-Instigate , comprise Inspired Teaching’s approach to engaging students in inquiry-based learning. 

When they are engaged in the Wonder-Experiment-Learn Cycle, students are immersed in learning. They take the lead in designing authentic learning experiences around their own interests and their school’s standards of learning. Each discovery leads to a new question which in turn leads to more wondering and more learning. In the Wonder-Experiment-Learn Cycle, Learn is not a destination or an endpoint; it is a deeper understanding, leading to a deeper wondering and new possibilities that create new entry points to further exploration. The cycle continues because what students have learned generates more wonderings that require more experiments that foster more learning – and on and on.

The Observe-Plan-Instigate  Cycle is t he work of an Inspired Teacher. While a student is expected to follow the Wonder-Experiment-Learn Cycle, the teacher joins them on the learning journey while following their own cycle of Observe-Plan-Instigate . This cycle ultimately serves to ensure an inquiry-based atmosphere is at play in the classroom.

Jaqueta Abbey

Teaching and learning specialist.

Jaqueta is the Teaching and Learning Specialist for Inspired Teaching. In addition to her current role with Inspired Teaching, Jaqueta is a first-grade teaching assistant. Her background features a variety of traditional and non-traditional experiences in the field of education, including working as an adjunct professor, teaching summer reading programs to children and adults, and tutoring children in the foster care system. Jaqueta earned a B.A. in Communication Studies from the University of North Carolina at Chapel Hill, and an M.A. in Interactive Media from Elon University.

Creative self-expression! In addition to my passion for storytelling, I love dancing of all kinds. I've studied belly dance, bachata, and Brazilian Zouk among other styles. I also enjoy glass fusing, crocheting, photography, and cross stitching. These art forms allow me to express myself and build connections with other people at the same time. I think life would be a lot less vibrant without artists and storytellers!

Michelle Welk

Communication & marketing specialist.

As Communications and Marketing Specialist, Michelle is responsible for finding and creating new ways to highlight Inspired Teaching and promote its programs in order to expand and deepen the organization's impact. Michelle has worked in communications in an array of settings, from creative agencies to state politics to national nonprofits. She has a BA in Journalism from Temple University in Philadelphia and is passionate about education, access, and equity. 

My son, the beach, making a persuasive argument and good food!

Max Peterson

Real world history assistant teacher.

Max received his Bachelor’s degree in History and African American Studies from Boston University in May 2016. He has worked in museum curation at the Museum of the White Mountains in New Hampshire and the Smithsonian National Museum of American History. Max has worked with young people of varying ages from young children to young adults transitioning to college.

Feedback and Accountability 

We grow through feedback and an understanding that the quality of our work is a reflection of what we are learning, but the shift to remote learning this spring disrupted a lot of the tools teachers were used to using to evaluate student growth. How might we do things differently this fall? Participants in this workshop will explore ways to bring meaningful assessment into the virtual and/or socially-distanced classroom and approaches to student feedback that strengthen motivation, and build relationships and achievement.

Time: half day Appropriate for: all educators at all grade levels

Sign up to learn more!

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Rethinking How We Spend Time 

The teaching profession is already rife with time-consuming activities that don’t always benefit our students. Navigating the challenges of online, hybrid, or socially distanced learning means we have to be even more thoughtful about where and how we spend our time. In this workshop participants explore ways to make their work more efficient and the precious time they have with students more productive, and even enjoyable.

Centering Students and Checking Bias

Our assumptions about students often get in the way of meeting their needs. This is especially true when we don’t have the same opportunities to get to know them in person. What messages are we unintentionally conveying through our email or video communications with students and their families? What steps can we take to make online learning equitable and respectful for all our students? This workshop offers participants a framework for decision-making as they plan for the new school year, an opportunity to critically examine their practice, and concrete strategies for elevating student voice and engaging productively with students.

Setting Goals and Creating Structure Online

Can we have the same goals in online learning that we do in the physical classroom? Yes!...And, online learning offers different means of achieving them. Participants will evaluate specific goals in their curriculum and explore ways to structure their time with students to efficiently maximize impact. 

Building Community in Uncertain Times

One of the big concerns teachers have about the upcoming school year is how they’ll get to know their students if their only encounters are through a computer screen or in-person but socially distanced. In this hands-on workshop participants will learn and practice strategies for community building online and/or in modified classrooms and craft a plan for learning all about their students in the first weeks of school. 

Jenna Fournel

Director of teaching and learning.

Jenna Fournel has been involved with Center for Inspired Teaching since 2004 and has worked in the education field for more than 20 years. She began her career as a high school English teacher and has served as Director of Communications for both Inspired Teaching and the National Council of Teachers of English. Her overarching professional goal is to do what she can to make the world a kinder place. She believes investing in the education of our young people is the best place to start.

Bella Cavicchi

Teaching and learning coordinator.

As the Teaching and Learning Coordinator, Bella manages Inspired Teaching’s digital presence and supports the organization’s efforts to reach new communities of educators and students. She believes passionately in honoring the voices of young people, and in and outside of the classroom, she strives to create inclusive spaces where students’ curiosity can thrive. She holds a B.A. in Literacy and the Performing Arts from Brown University and an MPhil in Arts, Creativity, and Education from the University of Cambridge. Currently, she lives and works as a drama teacher in London, where she is inspired daily by her students' creativity!

Chair; CFO, Options Solutions

John Nolan is a finance executive with over 30 years of of experience at organizations of various sizes. He has served in “C” level positions at public, private equity and private companies in the SaaS, Management Consulting, Telecommunications and Computer Hardware industries. He has deep experience in implementing and improving controls and other financial processes across organizations.

He is currently the CFO and CCO of Options Solutions, LLC, an investment advisory firm. Formerly, served as the CFO of Determine Inc., an international provider of contract management and procurement software. Prior to that, John spent a decade as CFO and then CEO of Quadel Consulting, a provider of services to low income housing programs. John’s other professional experience includes 3 years at IBM and 15 years at MCI, where he ran Corporate Finance for the Fortune 100 company.

He holds an undergraduate degree from Tulane University, an MBA from the University of Texas at Austin, and is a licensed CPA. John’s work with non-profits has primarily focused on educational organizations. He served for five years as the Treasurer of the Blessed Sacrament School board in DC. For three years he was on the board of Imagination Stage (IS) of Bethesda, a youth focused arts and education organization. John also served for six years on the corporate advisory board of So Other Might Eat (SOME), the DC based poverty services organization that is greatly expanding its job training programs.

Mr. Nolan has spoken on financial leadership and cost analysis at Chief Financial Officer Magazine, Better Management Live and IDC conferences. The costing systems he put in place at MCI received the Enterprise Intelligence award from the software company SAS.

Want to bring Inspired Teaching to your team or school?

Access school or district professional learning funds:  Some districts have professional learning discretionary funding for schools, or other funds that can be accessed for this purpose. Principals, district supervisors, curriculum supervisors, professional learning directors, and superintendents are good people to check with.  Depending on how many colleagues at your school participate, and the subject of the course, you may be able to access school improvement funds as well (e.g., for a course in Relationship-Based Classrooms, which would address school climate).

Talk to your PTA  representatives. These groups often have grants and money set aside for professional learning and school improvement.

Donors Choose is an organization where educators can post projects for donors to browse and fun, including professional learning that is used to further your craft.  Go to their website  to create a free account and find out more. Remember to post your project to social media, so that your friends and family can see the work you're doing and share it with others!

The  NEA Foundation for the Improvement of Education   awards grants that support the professional learning of public school teachers and faculty in public institutions of higher education. Grants may fund professional learning experiences, such as summer institutes or action research, mentoring experiences or lesson study. Professional learning must improve practice, curriculum and student achievement, and recipients must put professional leadership into practice by sharing what they learn with their colleagues. For specific information, visit the NEA Foundation’s  application instructions  page.

Fund for Teachers   is unique in that it awards grants for professional learning based on the principle that the teacher is the one who knows what they need to grow as an educator. These grants are self designed and allow teachers to create their own professional learning opportunity based on what is most beneficial to their teaching in their own opinions. The  application  encourages educators to think about their objectives, motivations and the impact their particular plan of action will have on students. Applications are due in January.

The McCarthey Dressman Education Foundation provides  Teacher Development Grants  for individual teachers or small teams working in K-12 education. To foster insightful and innovative professional learning and growth, the grants allow you to implement new teaching methods and strategies in the classroom. Projects can take a variety of forms, but each of them must be geared towards having a significant and lasting impact in the classroom. Winners work closely with the foundation to implement their ideas and are awarded up to $10,000 for the first three years of the project.

Earn PLU hours while taking a workshop!

Washington, D.C. educators can receive PLU hours for participating in courses. Each day of a course is 6 hours of credit - we will provide a certificate upon completion of the course. Please see the  OSSE certification website  for more information.

Inspired Teaching Course Costs

A taste of inspired teaching, time & location, about the event.

Christine Sheridan

Program grant manager.

Nothing brings me joy in life like spending time with family and friends. I love being active and spending time outdoors, making stained glass, and trying new foods!