‘Experiments’ Category

Teaching Children About How Clouds Form

Monday, September 10th, 2018

Teaching children about how clouds form

At some point in our lives, we’ve all sprawled on our backs and gazed in wonder at fluffy, drifting clouds.

Technically, clouds are a massive collection of tiny ice crystals or water droplets — so tiny, they float way up in the air. But for your students, clouds are more than just dust and water. They’re mysterious, puffy objects that wander through the sky and constantly change into endless, wonderful shapes.

It can be challenging to communicate the facts about clouds without losing the wonder of them as well. Let’s take a look at the science behind clouds and their formation, along with some fun experiments to capture your students’ imagination.

How Clouds Form

Despite their cotton-like appearance, clouds are made from billions of tiny droplets of water.

All air holds water. Close to the ground, it’s just in the form of an invisible gas — water vapor. This warm air rises and gets colder the higher it floats. High in the sky, the air pressure drops and the once-warm air expands as it gets colder. Cold air isn’t able to hold as much water as hot air, so as the warm air cools, some of this water vapor condenses around very small pieces of dust or other pollutants. This water forms a tiny droplet around each particle. If the air is cold enough, the water freezes into little ice crystals. Billions of these droplets or crystals gather together to form a cloud.

What Is Condensation?

Condensation is a part of the water cycle and is an essential part of cloud formation. The change of water from a gas to liquid form, condensation happens by a shift in air pressure and temperature.

After a shower, your bathroom mirror “fogs up.” If you wipe the surface of the glass, small drops of water collect on your hand and the mirror. This condensation occurred because the hot air from the shower cooled dramatically when it interacted with the cold surface of the glass. The rapidly cooling air couldn’t hold as much water as warm air, and the vapor reverted to its liquid form.

In the atmosphere, warm air cools as it rises, and water vapor condenses around tiny pieces of matter. These drops or crystals of condensed water form clouds.

Other Common Questions About Clouds

Your students’ questions won’t stop at, “How do clouds form?” Clouds have dozens of fascinating qualities that naturally engage a child’s curiosity, so be prepared to answer a barrage of cloud-related questions. Here are three of the most common cloud questions.

1. Why Do Clouds Float?

How do these giant, fluffy objects stay high in the sky? Why don’t they sink down to the ground?

Because clouds come from warm air, they have a higher temperature than the air around them. As long as the cloud is warmer than the atmosphere around it, it will float suspended in the sky.

2. Why Are Clouds White?

Light travels through the air in waves with different lengths, and each color we see has a unique wavelength. The ice crystals or drops of water inside clouds are big enough to scatter the light of all seven colors almost equally, which makes them look white.

But we all know that clouds sometimes get gray and ominous. This is because the light that hits a cloud gets reflected back towards the sun, so the bottom of the cloud — the part we see — looks gray. In rain clouds, the water droplets are larger and scatter even more light, meaning less light makes it out the bottom of the cloud. Because they are denser than normal clouds, rain clouds are consequently darker.

3. How Do Clouds Move?

Clouds are tossed around by the winds high in the atmosphere. The highest cirrus clouds are carried by the zooming jet stream, which makes them move incredibly fast — sometimes over 100 miles per hour. Thunderstorm clouds generally move fast, too, but not that fast. Typically, a storm blows through an area between 30 and 40 miles per hour.

How do clouds float

The Different Types of Clouds

Clouds come in a wide range of shapes and sizes, but every type is highly specialized — just by looking at a cloud, you can tell how high it’s floating and can even predict the weather.

Clouds are broadly categorized into three groups based on height — cirrus, alto and stratus — although there are a few other kinds as well. We’ll break down the categories and examine the different clouds found within each.

1. Cirrus Clouds

Cirrus clouds are the highest clouds, forming above 18,000 feet in the atmosphere. There are three types of cirrus clouds: cirrus, cirrostratus and cirrocumulus.

  • Cirrus: These common high clouds give this category its name. Made up of ice crystals, cirrus clouds look thin and wispy and high winds blow them into long streams. Usually white, cirrus clouds predict pleasant weather, but watch them closely — they often indicate that the weather is going to change in the next 24 hours.
  • Cirrostratus: Thin and sheetlike, cirrostratus clouds often fill the whole sky. A bank of cirrostratus clouds is very thin, and sometimes you can see the moon or sun shining through them. Typically, if you notice cirrostratus clouds, expect a storm in the next 12 to 24 hours.
  • Cirrocumulus: These small, round clouds form long rows high in the sky. Look for cirrocumulus clouds during the cold winter months — if you see them in your sky, you can expect cold but fair weather. However, in tropical areas, cirrocumulus clouds can indicate the approach of a hurricane.

2. Alto Clouds

The “in-between” clouds, alto clouds hover anywhere between 6,500 and 18,000 feet in the air. There are only two types of alto clouds to remember — altostratus and altocumulus.

  • Altostratus: These blue-to-gray clouds typically cover the whole sky, and they are formed from both drops of water and ice crystals. In thinner areas, you might barely see the sun through them. Grab your umbrella if your sky is filled with altostratus — they often form before storms with continuously falling snow or rain.
  • Altocumulus: Gray and puffy, altocumulus form around water droplets instead of ice. Usually, altocumulus clouds huddle together in groups. Watch out if you see them on a hot and humid morning — thunderstorms will probably come in the late afternoon.

3. Stratus Clouds

These are the lowest-hanging types of clouds and form anywhere up to 6,500 feet. Three types of clouds are categorized as stratus clouds — stratus, stratocumulus and nimbostratus.

  • Stratus: This category is named after these gray and uniform clouds. Stratus clouds will often fill the whole sky, and they almost look like fog that hovers just above the ground. Stratus clouds often produce a light drizzle or mist.
  • Stratocumulus: Puffy, low to the ground and very gray, stratocumulus clouds gather in lines. Hints of blue sky peek out between the rows. Although stratocumulus clouds rarely produce precipitation, they can easily grow into rainy nimbostratus clouds.
  • Nimbostratus: These clouds are a dark, broody gray, and are often associated with continuous precipitation, either snow or rain. You won’t get storms out of nimbostratus clouds, though — just light or moderate precipitation.

4. Clouds That Grow Vertically

Both cumulus and cumulonimbus clouds grow vertically, towering high into the sky. But they have a few important distinctions:

  • Cumulus: These are the dreamy shape-shifting clouds, the ones perfect for lying on your back and trying to decide what they look like. Cumulus clouds are fluffy and white, resembling suspended pieces of cotton candy. Known as “fair-weather clouds,” cumulus clouds have a flat base and rounded tops, and they often float along only 3,300 feet above the ground.
  • Cumulonimbus: Giant and ominous, we all know cumulonimbus clouds as the clouds in thunderstorms. Often, high winds flatten out the tops of cumulonimbus clouds, giving these multi-layered clouds a distinct anvil appearance. With cumulonimbus clouds, expect heavy snow, rain, lightning, hail and sometimes tornadoes. These giants can grow up to 50,000 feet tall.

5. Other Types of Clouds

Some clouds don’t fit into the normal “cloud” categories. Here are a few of the most common:

  • Mammatus: These are the low hanging bumps that hang below cumulonimbus clouds. If you see a massive cumulonimbus with mammatus clouds, you can expect severe weather.
  • Lenticular: You’ll only see lovely lenticular clouds if you live around mountains. Because of both their extreme heights and the low valleys in between them, mountains redirect winds in wave patterns. These waving winds create soft and smooth lenticular clouds, which look like frisbee discs or even flying saucers.
  • Contrail: Who hasn’t looked in wonder at the long slashes of clouds left in the wake of airplanes? These short-lived clouds are called contrails and form from the condensation expelled by jet airplanes. The hot and humid exhaust of a plane reacts with the cold, low-pressure air around it, creating strings of clouds that stitch across the sky.
  • Fractus: These are the small, ragged fragments of clouds that have been torn from larger clouds. Fractus clouds don’t have a clearly defined base, change constantly, and are usually indicative of strong winds.
  • Fog: When we walk through fog, we experience what it’s like to walk through a cloud. This “cloud-on-the-ground” typically forms when warm southerly winds bring a wave of humid air into an area. The warm air blows over a much colder soil or snow, and it begins to cool from below. If the air can’t absorb any more moisture, the water will condense and create a cloud.

    Clouds come in a wide range of shapes and sizes

Hands-On Lessons

For an engaging look at how clouds form, try one of these two easy experiments — you’re sure to keep your students’ attention. Using experiments is a great way to easily communicate cloud facts to children, and to keep them focused throughout the lesson.

1. Cloud in a Bottle Experiment 

You don’t need many materials to create your very own cloud. Try this experiment to give your students a hands-on demonstration of the steps and ingredients required for clouds to form.


Here are the tools you need to collect:

  • 2-liter clear plastic bottle
  • Warm water
  • Matches


Follow these step-by-step instructions to create a cloud in your classroom.

  1. Pour warm water into the clear plastic bottle until it’s roughly one-third full. Twist on the cap.
  2. Squeeze the bottle tightly around the middle and then release. Have your students note that nothing happens — you still need another ingredient to make a cloud. Note — if the inside of the bottle is obscured by condensation, gently shake the bottle to let the water wash it away.
  3. Carefully, light a match and take the cap off of the bottle. Hold the lit match over the opening.
  4. Quickly, drop the match into the bottle and twist the cap back on.
  5. Once again, slowly squeeze and release the bottle. A cloud will appear when you let go and vanish when you squeeze.


There are three ingredients to cloud formation — water vapor, dust or other particles and a drop in air pressure. The warm water adds water vapor to the air trapped inside the bottle as it evaporates. But if you squeeze and release the bottle at this point, no cloud forms — the air doesn’t yet have any debris particles.

Once you drop in the match, the smoke gives the water vapor something to condense around. Now, when you squeeze and release the bottle, a cloud forms. The final requirement for clouds is a drop in air pressure. When you squeeze the bottle, you dramatically increase the air pressure, and it drops as you release. Viola — a cloud!

2. Cloud in a Jar Experiment

A variation of the cloud in a bottle experiment, this one requires a glass jar and some ice.


Before you begin, gather these supplies:

  • Glass jar
  • Ice
  • Jar lid or plate
  • Matches
  • Warm water


With only a few steps, give your students an up-close look at a cloud.

  1. Pour the hot water into a jar, until it is about halfway filled. Make sure the water is not too hot or that you have warmed the jar ahead of time — pouring hot water into a cold jar could cause the glass to crack!
  2. Twist the lid back on the jar, or cover the opening with a plate. Place some ice on top of the lid or dish.
  3. Let the jar sit for a little while and see that the hot water is creating some steam.
  4. Light a match and allow it to burn for a few moments. Blow out the match, drop it into the jar and quickly cover the opening with the plate of ice.
  5. The “cloud” will be much more visible. Lift the lid and see the cloud fade into the room.


The same principles are at work in this experiment as in the cloud-in-a-bottle process. To form, a cloud needs water vapor, air debris and a change in temperature and pressure. In this experiment, instead of squeezing the bottle, the ice drops the air temperature and pressure inside of the jar and a cloud is born.

Awaken your child's curiosity

Awaken Your Child’s Curiosity

At Science Explorers, we are dedicated to making science fun and engaging for your children. We use interactive and hands-on techniques to foster a kid’s natural wonder and curiosity. Some of our favorite activities include dissection, rocket launches, rubber eggs and tornadoes-in-a-bottle, to just name a few.

Read more about our summer science camps and after-school clubs, and feel free to contact us with any questions. We look forward to learning with you.

What Is Oobleck?

Thursday, August 16th, 2018


Oobleck is a non-Newtonian fluid. If you have no idea what that means, then you are certainly not alone. Most people wouldn’t know a Newtonian fluid if they drank it for lunch every day in the cafeteria.

Let’s put this in more understandable terms. Oobleck is a suspension, or a substance that can mimic the qualities of a solid or a liquid. These materials are also classified as non-Newtonian fluids. A Newtonian fluid has a constant viscosity, such as water or gasoline. As you might guess, the viscosity of a non-Newtonian liquid changes. Examples include silly putty, ketchup and, yes, oobleck.

So that brings us back to the question of what is oobleck exactly? It’s a substance made from a mix of cornstarch and water. It can feel like a solid when you hold it in a ball, but it becomes liquidy when you let your hand go loose. It takes the shape of whatever is holding it.

Oobleck got its name from a book by Dr. Seuss, called Bartholomew and the Oobleck. In it, the oobleck is a mystery substance that falls from the sky.

How to Make Oobleck

If you want to make oobleck for your kids, it’s fairly simple. You combine one part water to 1.5 parts cornstarch. If it seems a little too solid, add a few more drops of water. It should get to the point where it tears apart if you draw a finger quickly down the middle but comes back together quickly. Some people add food coloring to the oobleck to make it more appealing to children.

Here are a few things you can do with your kids to learn more about the liquid vs. solid question:

  • Let the oobleck sit in a glass for a few hours. Observe how the liquid and solid separate — this is because it’s a suspension and not a mixture.
  • Stir the suspension with a spoon. Ask your kids to predict how long it will take before it becomes difficult to move.
  • Take turns hitting the oobleck with your palm. Do you notice how hard it feels? Ask your kids why they think it becomes a solid when pressure is applied.
  • Put the oobleck next to a speaker and turn up the sound. Is it loud enough to make the oobleck become less viscous, as it does when you apply pressure?

Disposing of Your Oobleck

When you and your kids have finished your oobleck play time, be sure to dispose of it responsibly. Don’t put it down your garbage disposal. The thick material could cause a blockage. Instead, toss the oobleck into the trash can. You can always make more for another rainy day lesson.

Find More Fun Experiments for Kids

If your children enjoy learning about oobleck, then they may enjoy other science-related activities as well. Bring them to one of our after-school science clubs or science summer camps. We teach kids about science using fun, relatable projects. It’s the perfect after-school or summer treat for kids ages 4-11. Contact us today to learn more about our offerings.

Teaching Children About Acids and Bases

Tuesday, July 31st, 2018

Children learning about acids and bases

Have you ever tried to teach kids about the fundamentals of acids and bases, only to be met with groans and other bored reactions? We understand that that’s no fun. Maybe you’re excited about the concept and want to make it interesting for the kids, but are struggling to find a way to make such a potentially dry topic come alive.

The key to doing this is by showing your students just how far from dry this topic actually is. The reason they may be uninterested is because they might think of it as an obscure chemical concept that has no effect on them whatsoever. But what if you could prove that the opposite is the same? By showing your kids all the ways in which this concept is active in their everyday lives, you can help spark interest, exploration and excitement.

To help you do just this, we’ve pulled together a few quick tips and ideas for teaching kids about acids and bases. We’ll go over the basic concepts in simple language that’s appropriate for children as well as look at some fun experiments you can do to play with these ideas.

What Are Acids?

You may have heard of the term acid before, and you have likely heard something referred to as acidic. And while you may have a general idea of what these terms mean, it’s helpful to understand what these terms mean on a scientific level.

Think of beverages like lemonade or orange juice. Think of the delicious tangy taste you get when you sip either of these beverages. That tang is the direct result of these beverages’ acidic nature. The reason that these beverages and many other substances are naturally acidic is because they contain lots of hydrogen ions. An ion is a special type of atom or molecule that has an electric charge. A hydrogen ion, then, is one that has a tiny electrical charge.

Every substance in the universe is made up of hundreds and thousands of tiny atoms, molecules and ions. When a large number of those are hydrogen ions, the substance is acidic. In food, that means it will have a sour or tangy taste. Lots of things other than food can be acidic as well, though.

Water molecule

What Are Bases?

Base is a term we rarely use in everyday life, at least in this context, and that means it might be a slightly less familiar concept. One everyday example of a base substance is baking soda, commonly used to bake cakes, cookies and other sweet treats. If you try to taste this, you’ll see that it’s very bitter. If you rub it between your fingers, you’ll find it has a strange, soapy feeling. This is all because baking soda has a basic nature.

Basic substances contain lots of hydroxide ions. These are a different type of molecule with a small electrical charge. In foods, this means they will taste more bitter. Plenty of things other than food can be basic, however.

What Is the pH Scale?

The pH scale is another concept you may have heard of without much reference for what it is and how it works. But while the name might sound intimidating, the idea is actually pretty simple.

Think of the pH scale as a ruler that we can use to measure how acidic or base something is. There are 14 different possible point values on the scale, and each one represents a possible level of acidity or baseness. A substance is acidic if it has a pH level of 0 through 7, where 0 is the most acidic. A substance is basic, then, if it has a pH level of 7 through 14, where 14 is the most basic. If a substance has a pH of exactly 7, it’s neutral. This means it has equal amounts of hydrogen and hydroxide ions. Pure water is a neutral substance.

If an item measures at a 3 on the pH scale, then, we can see that this substance would be quite acidic, although not as acidic as other substances. Something that measures an 8 would be slightly basic.

pH scale

What Is an Indicator?

We mentioned earlier that certain foods are more basic or acidic, and you can tell this by tasting them. Lemonade, for example, is clearly sour and tangy, helping us realize that it must be acidic. Baking soda, on the other hand, is bitter and we can easily recognize that it is more basic.

What about things that aren’t food, though? After all, plenty of different substances throughout nature have either an acidic or basic nature. Logically, we can’t go around tasting all of these different things to tell where they fall on the pH scale. So how do we test them?

We use an indicator to compare acids and bases. An indicator is a special type of substance that tells us whether the item in question is more acidic or basic. Believe it or not, there are a few naturally occurring indicators that we can use to determine the pH of a substance. Litmus and turmeric are great examples of natural indicators.

Out of all of those natural indicators, the one we use most frequently in a classroom setting is litmus. This is a type of material that comes from lichens, which are plants that grow along walls, trees or rocks. Litmus has a naturally purple color, but it can change its color. When it comes into contact with an acidic substance, it turns red. When a basic solution touches it, it will turn blue. Because of this unique property, litmus is a handy indicator. When we use it today, we most often use it in the form of small sheets known as litmus papers.

Where Do We Find Acids and Bases in Nature?

While acids and bases might sound like obscure chemistry terms that we would never encounter except in a lab, this isn’t true. Acids and bases are all around us in daily life. Lots of plants have leaves, stems, roots and flowers that are either acidic or basic. Plenty of fruits are acidic or basic, and even ordinary things like soda and milk fall somewhere on the pH scale.

Even inside our bodies, there are lots of acidic and basic substances. There are acids in our stomach that help with digestion, and our muscles produce acid when we exercise. Our pancreas is basic and helps in the digestion process as well. All these different acids and bases work together in our bodies to keep things running smoothly.

Acids vs. Bases Experiments for Kids

Because acids and bases pop up all over the place in nature, as well as in plenty of human-made settings, what are some fun and interesting ways to play with these ideas? As it turns out, there are plenty. Try a few of these experiments to get everyone interested in the ideas of acids and bases.

1. The Red Cabbage pH Test

Red cabbage is a great natural indicator and is perfect for use in classroom experiments. To get this test started, slice some red cabbage, put it in a pot with some water and let it simmer for 30 minutes or so. Strain the liquid out, set it aside and then you’re all ready to get started.

Grab a couple of small rectangles of white paper. Index cards are a great choice, but you can also cut out regular pieces of scrap paper. Soak them in the red cabbage water and let them dry.

Take a white paper plate or a thick sheet or white paper and drip a few drops of your cabbage water onto this surface. Take an acid, such as lemon juice, and a base, such as baking soda, and add a small amount into different sections of your cabbage water samples. The water will change color as a result and will look like magic in the process. With a solid explanation of bases and acids under their belts, kids will enjoy watching the colors change in response to the different liquids.

Another way to use this cabbage water is to pour a few inches of it in two separate glasses. Add water to these glasses as well, until they’re about two-thirds of the way full. Finally, add a base to one glass and an acid to the other and watch the entire glassful of liquid change colors.

Once your homemade litmus papers are dry, cut them into smaller strips. Now the kids can perform their very own litmus tests with all kinds of different materials and substances. Pull different things out of the fridge and let the kids use the papers to test them. Some good things to try include pickle brine, apple juice and soda. Before you dip the papers into the substances, ask the kids to guess whether an item will be acidic or basic, and make a game out of it. Show them how to record their predictions, along with whether or not they were correct.

Of course, if red cabbage is unavailable or if you’d rather not go through the process of creating your own litmus papers, you can simply buy prepared litmus papers in many different stores. These pre-made papers will work in exactly the same way and can be used to perform the same tests.

Red cabbage

2. The Copper Coin Experiment

Do you have any tarnished copper coins lying around? If so, they can make a great experiment.

For this to work, you’ll want to take a few different cups and pour a small amount of a liquid solution into each cup. Try a few different solutions that you know to be acidic, and a few others that you know to be basic. Then, all you have to do is drop the copper coins into the solution. You can lay them flat in the bottom of the cup, although the results will be more striking if you can stand the coin on end so that only half gets soaked in the liquid.

The acids will dissolve the tarnish that has collected on the copper coins, restoring them to their original shiny selves.

3. The Raw Egg Experiment

Another great experiment to try involves a raw egg. While this one is fun to do and fun to watch, the kids might also enjoy making predictions with this one and trying to guess what will happen.

For this experiment, keep things simple. Take a raw egg and submerge it in a bath of vinegar. Ask the kids what they think will happen. As you might be able to guess, the highly acidic vinegar breaks down the shell and effectively turns it into an acid-cooked soft-boiled egg. It will even bounce if you drop it carefully.

4. The Jet-Powered Boat

This experiment works best in a bathtub, a large sink or even a blow-up pool in the backyard. To get started, take a regular plastic water bottle and drill a hole straight through the cap. Thread a thin straw through this hole and use some modeling clay to help you hold this straw in place and plug the gaps around it. When you eventually submerge the bottle in your pool, this clay will also help weigh that end of the bottle down and keep it underwater.

Fill the water bottle with a solution of half water and half vinegar. Be careful not to fill the bottle all the way, and instead leave a space of empty air near the top. When your bath or pool is filled, set the experiment in motion by adding about half a teaspoon of baking soda to the bottle. Immediately cap the bottle and cover the end of the straw with your finger before placing the bottle in the pool and letting go.

The acid of the vinegar and base of the baking soda will violently react with one another, fizzing and creating “jet fuel” that will shoot out the end of the straw and propel the boat across the pool.

Child looking into microscope

Keep Your Kids Interested in Science

Did your kids enjoy learning about these fascinating ideas? Did their eyes light up as they watched these concepts come to life in front of them in the form of exciting experiments? If so, it’s important to nurture and encourage these interests.

If any of your science adventures have sparked a kid’s interest in science, consider enrolling them in a science summer camp or an after-school science club. Both of these are great ways to allow kids to continue exploring these interests and learning new and exciting concepts in the company of their peers.

If you live in the Pennsylvania, New Jersey, Delaware or Maryland area, our Science Explorer camps are week-long events in the summer that are held at schools, museums, libraries and other educational settings near you. If summer has already ended, however, there’s no need to worry. We also offer after-school programs for kids in grade one through five, although this will vary from school to school.

Visit our information pages to learn more about our summer programs and after-school clubs. If you have any questions, don’t hesitate to contact us. We’ll help you find a program that will be the best fit for your young science explorer!

Create Your Own Lava Lamp

Friday, July 6th, 2018

Lava lamps are the epitome of 1970s cool. You may have had one in your own room growing up as a kind of throwback to the era of disco and bell bottoms. But did you ever think about the science behind the lava lamp?

It gets the pretty colors and bubbles from the reaction between the water and oil. Oil has a lower density than water, allowing it to sit on top of the water. The density of the coloring in the lava lamp is higher, which is why it sinks to the bottom and mixes with the water while the oil moves up.

Give your kids a groovy science lesson by working together to make your own lava lamp. While this won’t have the light portion and won’t get plugged in, it will still make a beautiful illustration of how oil and water interact.

Lava lamp

Supplies to Make Your Lava Lamp

You will need the following materials:

  • Empty plastic water bottle, label removed
  • Food coloring
  • Water
  • Cooking oil
  • Alka-Seltzer tablet

Make Your Own Lava Lamp

Fill the bottle two-thirds full of oil. Then add water until there’s around an inch remaining at the top. Watch what happens to the water with your kids. It will sink slowly beneath the oil layer, creating lots of bubbles. When the bubbles have stopped, dribble a couple drops of food coloring into the bottle.

Again, it may take a few minutes for the food coloring to work its way to the bottom. As you wait, break the Alka-Seltzer tablet up into four pieces. When the food coloring has settled, drop one piece of the tablet at a time into the lava lamp. It will spark a small eruption of water and color in the lamp. Wait until the fizzing has stopped, then continue to drop in a piece at a time.

You can put the top on the lava lamp when you are done and turn it upside down to enjoy the oil-water separation again. You can also pop off the top anytime and add more Alka-Seltzer tablets.

How Lava Lamps Work

The Alka-Seltzer produces gas, which is lighter than either the water or oil, so it rises to the top along with a bit of water that comes along for the ride. When the bubbles pop, the water sinks back to the bottom because it has a higher density than the oil. A few variations of the experiment you may want to try to get your kids thinking about how the lamps work include:

  • Sprinkling salt into the lamp
  • Adding an entire Alka-Seltzer tablet at once
  • Putting the top on the bottle after adding a piece of tablet

Find More Fun Activities Like Making Lava Lamps for Kids

If your child can’t get enough of cool science experiments like this one, perhaps it’s time to sign up for a course with Science Explorers. At our science summer camps and after-school science clubs, we do activities that bring science to life for kids ages 4-11. If you live in Maryland, Delaware, New Jersey or Pennsylvania, contact us today to learn more.


Learning About Surface Tension: Color Changing Milk

Friday, June 8th, 2018

Milk surface tension

What is surface tension? It’s the tension in a liquid’s surface film, which takes up the least amount of space possible because of the fluid’s elasticity. The cohesion of liquid molecules keeps the surface of liquid placid and still. The particles in the liquid will adhere to each other more tightly than other things, hence creating the tension.

Of course, trying to explain surface tension to kids in a language they can understand is a much greater challenge. It’s easier to have them do an experiment that demonstrates the principles of surface tension and shows them how it can change. We’ve picked one that involves an everyday beverage your kids will see in an entirely new and exciting way.

The result of this experiment? Tie-dye milk. It’s really pretty cool.

Materials for the Color-Changing Milk Experiment

You will need the following materials to make color-changing milk:

  • Whole or two-percent milk
  • Q-tips
  • Dish soap
  • Food coloring, four shades
  • Small dish

How to Perform the Color-Changing Milk Experiment

Pour some milk into the dish. Add four drops of food coloring — one of each color — to the middle of the milk, spacing them out enough so that they do not touch each other.

Ask your child what they think will happen when you add the cotton swab to the milk. Have them state their prediction out loud. Then submerge the end of the Q-tip in the center of the milk, near where you put the color dots. Avoid stirring. You just want to touch the milk. Note what happens to the colors and the milk.

Remove the cotton swab. Dip the tip of the other side gently into the dish soap. Once again, ask your child to predict what will happen when you touch the center of the milk the second time. Do they think the colors will react the same? Or will they do something different?

Submerge the soap-covered Q-tip into the center of the milk, and keep it there for up to 20 seconds. Note how the colors seem to explode. Talk to your child about what looks different this time versus the first time you stuck the cotton swab in the milk.

Change the Experiment to See Different Things

Pull the tip of the swab out of the milk and dab it into the dish soap once more. Then put it back in the milk. This time move it around to touch other colors. Watch the colors after you remove the Q-tip. Are they still moving?

Ask your kids what they think would happen if you did the experiment with a different liquid. Would they see the same effect with, say, water as they did with milk? Why or why not? Get a dish of water and see if their hypothesis holds up. You can carry out the same experiment several times using different liquids.

Talk to your kids about the concept of surface tension and how you saw it on display with the milk. Milk and water both have surface tension, but milk has fat that allows this experiment to play out. The food coloring is not as dense as the milk, and so it does not mix until it comes into contact with the soap, which breaks the fat in the milk down.

Enjoy More Surface Tension Experiments for Kids

Do your children love learning about science through experiments like this one? Bring them to our science summer camps and after-school science clubs, where they can have more fun exploring concepts like surface tension. Contact us to learn more about our activities in PA, NJ, MD and DE.

Rubber Egg Experiment for Kids

Tuesday, May 22nd, 2018

Rubber Egg Experiment

Have you ever heard of a naked egg experiment?  It’s a trick involving dissolving eggshells — one of those fun kitchen experiments that feels almost absurd to call a lesson. Everyone will want to take part in this cool activity.

Why do a rubber egg experiment? It’s a great way to teach kids about the different parts of an egg, what their functions are, and how a chemical reaction works. So gather your supplies and get ready for a scientific exploration everyone in the family will find fascinating.

Supplies for the Rubber Egg Experiment

You will need to gather:

  • One egg
  • Vinegar
  • One jar or glass

How to Begin the Rubber Egg Experiment

Before you start, ask your kids to write down their predictions for what will happen to the egg. Give them a few prompts if they have difficulty. Do they think it will change color? What will it feel like? Will it change shape?

Place the egg in the jar. Add enough vinegar so that the egg is completely submerged. Your kids may ooh and ahh over the bubbles that arise during this step.

After 24 hours, dump the first batch of vinegar and cover the egg with new vinegar. Let it sit for six more days. As the days pass, your kids will note how the shell dissolves, hence the nickname “naked egg” experiment.

Remove the egg from the vinegar. While it has not been cooked, it will take on a rubbery feeling from the vinegar. It will also have a thin brown slime on it, the remnants of the shell. You can gently slough or rinse it off.

Exploring the Rubber Egg

Now comes the fun part. Gather a few tools to help you with your scientific investigation, such as a flashlight and a magnifying glass. Let your kids handle the egg. Ask them how it feels. Is it soft? Hard? How is this similar to or different than a hard-boiled egg? Encourage them to turn it over and look at every part. You may even let them bounce it gently on the kitchen counter — just don’t do it too hard, or the egg will explode.

Take your flashlight and shine it on the egg. Can you see the yolk? What does it look like? Roll the egg gently back and forth as you shine the light on the egg. Can you see the yolk moving?

Use the magnifying glass to explore the different parts of the egg. What do you see? Ask your kids what they think each piece is and what its function is within the egg.

Breaking the Egg

When you have finished looking over every nook and cranny of the egg, you can let your children break it open. This can be messy, so you may want to do it over the sink or in a bowl. Let them poke a hole in the egg. They can see how much pressure it takes to break it open and play with the membrane after it comes off. Just make sure to have them wash their hands when they’re done.

Discover other fun home experiments with kids by sending them to our after-school science clubs or science summer camps. We do loads of activities designed to teach them about science while they have a good time. Our programs in Maryland, New Jersey, Delaware and Pennsylvania are geared to kids ages 4-11. Get in touch today to learn more about Science Explorers.

Tornado in a Bottle Experiment

Thursday, April 5th, 2018

Tornadoes are violent winds that create a funnel underneath a storm system. As the winds rotate, they often pick up speed, and eventually, they form what is called a funnel cloud — a column of water droplets, dust and other debris with a tapered shape extending from the base of a thunderstorm.

This is a pretty weighty concept to explain to kids, though. It’s much easier to simply let kids observe a tornado, seeing how the winds move and what happens when it starts to die down.

Of course, it’s not safe to take your kids to see a real tornado, so how about the next-best thing? Make a tornado in a bottle. This experiment allows children to mimic the patterns of this weather occurrence without facing any of the dangers a real tornado brings.

Materials for Tornado in a Bottle

To perform this experiment, you will need:

  • A plastic or glass bottle with a narrow top and a cap, such as a clean soda or iced tea bottle
  • Water
  • Funnel
  • Dish soap
  • Glitter

How to Perform the Tornado in a Bottle Experiment

Add water to the bottle until it is filled up to about two inches from the top. Add two squirts of dish soap. Finish it off with a pinch of glitter. Screw the top back onto the bottle.

Turn the bottle upside down. Grasping it by the neck, twirl it in a circular pattern as fast as you can. Stop after about 20 seconds and hold the bottle. You will see a swirling funnel of glitter that looks like a tornado. Have your child watch as it continues to spin in the direction you were moving the bottle.

It may take a couple of tries to get the tornado to function correctly. Once it does, explain to your child why this is happening to help them understand the forces at play with a real tornado.

What Makes the Water Spin?

The water in the bottle is responding to centripetal force, a force that acts on a body moving in a circular motion. The motion is directed toward the center, which is also referred to as the vortex. This is what catches the glitter and makes it move.

Have your child do variations on the experiment, and note whether they make a similar tornado. Have them move the bottle in the opposite direction. Then have them move the bottle up and down. Ask them to predict before they make the movement whether another tornado will form.

Tell your child about other vortexes in nature. Examples include hurricanes and tornadoes that form over rivers, lakes or other bodies of water, which are called waterspouts. See if they can come up with any other places a vortex might occur.

Enjoy Other Weather Experiments for Kids

If your child can’t get enough of the tornado in a bottle, you can also turn them on to other weather experiments. We hold them regularly at our science summer camps and after-school science clubs that take place throughout Pennsylvania, New Jersey, Delaware and Maryland. Contact us to learn more about them.

Space Food

Monday, December 4th, 2017


Have you ever asked yourself, “What do astronauts eat in space?” If so, you’re not alone. When you visit a science center, it’s not unusual to see kids — and some adults — walking around with astronaut ice cream and a few other astronaut foods because they’re curious about what’s eaten in space.

Today, the food astronauts eat in space is remarkably similar to what people eat on Earth, although you won’t find cookies or bread on the menu. That’s because the crumbs from foods like these can float into a spacecraft’s nooks and crannies and damage the ship.

Space Food Facts: A Quick Overview of the Evolution of Space Food

As space voyages started to become longer over the years, scientists were forced to develop food that astronauts would enjoy eating and that had the nutrients necessary to keep them healthy. The first space meals had the consistency of baby food. These meals were packed into tubes that resembled toothpaste tubes. When astronauts were hungry, they simply squeezed their food directly into their mouths.

When astronauts began to complain about their space food, scientists introduced freeze dried foods that could last for long periods of time without having to be refrigerated. To eat these new foods, astronauts would use a water gun to add moisture to their meal packets, and then they’d wait a few minutes before digging in.

During the NASA Apollo missions, astronauts were able to rehydrate their food with hot water for the first time. This made it possible for them to dine on new space foods, including chocolate pudding, soup and pasta.

In the 1970s, NASA unveiled a specially-designed tray that astronauts could use to heat their food. At the same time, refrigerators were installed on vessels such as the Skylab space station. This made it possible for astronauts to eat fresh fruits and vegetables while they were in space.

Since the 1980s, the food astronauts eat in space has closely resembled what we eat on Earth. To ensure astronauts have enough food at all times, spacecraft like the International Space Station receive regular food “shipments” that are delivered by an automated space vessel, such as the ESA’s Automated Transfer Vehicle or the Russian Progress.

Space Food Experiment for Kids

If your children are curious about space food and you’re looking for a space food experiment for kids, consider conducting a space pudding experiment. Here’s what you need:

  • Instant pudding mix
  • Powdered milk
  • Water
  • Zip top bags (quart sized bags work best)
  • Measuring spoons
  • Measuring cup

To make space pudding, give one zip top bag to each child who wants to make a yummy snack. Put one tablespoon plus two teaspoons of the instant pudding mix into each bag. Then, put one tablespoon plus two teaspoons of powdered milk into every bag. Pour a little less than 1/2-cup of water into each bag and seal the tops.

Tell the kids to start agitating the contents of their bags by squeezing and squishing them to mix the ingredients together. Once the pudding sets up, snip one corner on each bag and let the kids enjoy some homemade space pudding!

Space Academy Camp

At Science Explorers, we want kids to fall in love with science, which is why we offer fun-filled after-school clubs and summer camps for them to participate in. Our Space Academy Camp is one of our most popular summer camps because it introduces youngsters to the countless wonders of space.

To learn more about our camps and clubs or to sign your child up for one of our programs, contact us today.

We offer our camps and clubs to children ages 4 – 11 across parts of Pennsylvania, New Jersey, Delaware, Maryland, New York and Virginia.

Make Your Own Rock Candy

Monday, October 16th, 2017

Rock candy

*Please note parental participation is required for this experiment due to working with scalding liquids.

Can a single science experiment be alliterative, fun and yummy all at the same time? When it comes to making your own rock candy, the answer is absolutely!

Involving words like “solutes,” “solvents,” “sedimentation,” “solutions” and “supersaturated,” talking about making rock candy obviously fits the bill for being alliterative. It also requires the involvement of both adults and children, so making rock candy is a fun activity for all ages.

And since the final product has “candy” in its name, making rock candy is sure to produce a tasty treat at the end of the experiment.

What You’ll Need

To pull off a rock candy experiment for kids, you’ll need to gather a few supplies. Here’s what you’ll need to get together ahead of your experiment:

  • Three cups of granulated sugar
  • One large glass container
  • One smaller glass container
  • One pencil
  • Wax paper
  • One cup of water
  • One heavy spoon
  • Paper towels
  • String (clean, preferably new)
  • Food coloring (optional)

Since you’ll need a heat source for your rock candy science experiment to work, it’s wise to set up shop in your kitchen near your stovetop or microwave.

How to Make Rock Candy

Once you’ve gotten the ingredients and tools necessary to make rock candy together, call your kids into the kitchen because it’s time to get started! Here are the steps you and your children should follow to make rock candy successfully:

  • Pour three cups of granulated sugar into your glass container.
  • Add one cup of water to the sugar and stir. The chemistry already begins at this point of the experiment. Instruct your kids to watch the water as it makes its way through the sugar. Explain that the sugar is a solute, the water is a solvent and that together, they’re forming a solution. You can also talk about how the solution is thick or viscous because there’s significantly more sugar than water in the container.
  • Once it’s stirred thoroughly, the solution must be heated until it boils. You can use a microwave or your stove to warm up the solution. Reminder: It’s advisable for an adult to handle this step to prevent any little ones from getting burned.
  • When the solution is returned to a heat-safe counter or tabletop, stir it again and let the kids see how heat has changed the mixture.
  • Heat the mixture for another two minutes without letting it boil over, and then stir it again. Point out that the solution is now less thick than it was prior to you heating it up.
  • If you’re using food coloring, add some to your solution. Be sure the color of the mixture is pretty dark to produce the best end result.
  • Pour the solution into the smaller glass container.
  • Tie a piece of string to the middle of your pencil and cut the string so that it’s two-thirds the length of your small glass container. It’s important to use clean string, which is why it’s advisable to use new.
  • As your child holds the pencil, have him or her lower the string into the solution until the string is soaked through.
  • Once the string is fully soaked, lay the pencil and string on wax paper so they make what looks like a cross (i.e. the string should be perpendicular to the pencil).
  • Let the solution cool down and let the string dry out.
  • When your solution reaches room temperature and your string is completely dry, suspend the string in the solution by laying the pencil over the top of your container so it can work as an anchor.
  • Cover the top of your container with some paper towels and put it in a location where it can stay put for about a week.
  • Take a look at your solution from time to time and see the crystals that have formed along the sides and bottom of your container and your string.
  • At the end of the week, use the pencil to remove the crystal-covered string from the solution.
  • Enjoy your rock candy!

The Science Behind Rock Candy

When you heated and stirred your sugar and water solution, you made what’s called a “supersaturated solution,” which had way more solutes than your solvent could dissolve at room temperature. Since you heated the solution, the water was able to dissolve the sugar faster because water molecules move quicker when they’re heated. As your solution cooled, the solutes remained in your mixture even though your supersaturated solution contained more sugar than the liquid could reasonably handle.

Over time, the sugar solutes fell out of your solution as particles or precipitate. As they did, they connected with other particles to form a crystal, which is your rock candy.

After-School Science Clubs

If your children enjoyed making rock candy, they’ll love the fun experiments we do every day during our after-school science clubs. Our educational clubs are open to children ages 4 – 11 across parts of Pennsylvania, New Jersey, Delaware, Maryland, New York and Virginia.

Disappearing Messages!

Tuesday, August 15th, 2017

It’s almost a rite of passage. At some time in every childhood, you absolutely must experiment with disappearing ink. Many a secret message has been written and delivered using this time-honored method of communication.

What kids who write these notes may not realize is they’re also participating in a scientific experiment. It’s true — whether your children are pretending to be a secret agent or a spy, they are actually becoming a part of the scientific process, benefitting from something called oxidization that keeps their messages hidden until they fall into the right hands.

Of course, what your kids care about is the “magic” that allows them to write and deliver these messages so effectively. The best part is, you don’t need to buy a secret agent kit or go to spy school to help them make disappearing messages. They can do it with just a few things you have sitting around the house, such as lemons and light bulbs.

How Oxidation Works

First, a quick primer on how the “magic” works. In oxidation, a compound borrows electrons from another compound. In most, though not all, of these reactions, oxygen is one of the compounds. This is because oxygen easily combines with other elements. It pulls in electrons from their atoms, transforming an oxygen atom into an ion.

We see the results of this reaction, though you can’t actually see the electron exchange happening unless you have a powerful microscope. One of the most obvious examples is rust. When you see rust, it means oxygen has been taking electrons from iron. This corrosion forms on iron or steel as a result of oxidation.

For the lemon used in the following experiment, the juice oxidizes when it’s heated. You could also substitute other substances for this experiment, such as vinegar or milk, which will react in a similar way.

Make Your Own Disappearing Messages

Here’s a simple way to let your kids make their own disappearing ink messages.


  • Lemon
  • Lamp or other light bulb
  • Water
  • Paper
  • Paint brush or cotton ball

Cut the lemon in half. Fill a bowl with a few drops of water, and squeeze the juice of a lemon into the bowl. Mix them together with a fork or coffee stirrer.

Dip the cotton ball or paint brush into the lemon juice-water mix. Use it to write on the paper. When you’ve finished your note, allow the paper to dry. It should be white and carry no hint of what you’ve written.

When you want to reveal your message, put the paper directly beneath a lamp or another light bulb. Be careful not to hold it so close that it might burn. The letters will be revealed on the page as the paper warms up.

Science Fun for Everyone

The best part about the experiment is that it illustrates what can be a difficult point to explain. That’s the fun of scientific experimentation. When you do something, instead of just talking about it, it helps kids visualize the process. This can often spark new interests in kids. They see something happening that they hadn’t expected, such as an everyday substance like lemon juice producing a secret message, and they get excited to learn more.

If your child is interested in other experiments like this, you can always check out our list of summer science camps and after school science clubs available to children ages 4-11 in PA, NJ, DE & MD.