27 SCIENCE EXPERIMENTS FOR KIDS - SCIENCE - 2025

The scientific experiments are one of the best ways to explain concepts of biology, chemistry or physics to children in a dynamic, practical and interesting. In addition, they can show the usefulness of the subjects that children study.

Although education has traditionally been based on a one-way relationship -the teacher explains and the student receives information-, teaching is more effective when it is dynamic, practical and the student knows the usefulness of what he learns.

We are going to show a list of experiments that you can practice with children. It is always important that you are present as an adult to avoid possible incidents and explain what to do.

Scientific experiments with water

Water is a natural and vital element for human beings. From a very young age, people are in contact with this natural resource.

However, one is rarely aware of the chemical reactions that can occur when this liquid mixes with other substances.

Domestic rainbow

With this experiment we will show how you can create a rainbow at home.

Materials needed for the experiment:

• A glass of water
• A spray bottle
• A piece of paper
• Sunlight

Procedure to follow:

The first thing to do is place a glass of water on a table, chair or window where the sunlight reaches.

Then a sheet of paper should be placed on the floor / ground, just at the point where the sunlight hits, in the path of the line of the glass.

Subsequently, warm water is sprayed in the place where the sun enters. All elements must be aligned. Including the paper that was placed on the floor.

Position the glass and paper in such a way that a rainbow forms.

In this video you can see an example.

Ice fishing

This experiment will show you a little "trick" to lift ice cubes with a rope, using only salt.

Materials needed for the experiment:

• Small paper cup
• Bowl or tray with ice cubes
• 1 glass of water
• Thread, string, or twine about 6 to 8 inches long
• Salt

Procedure to follow:

The first thing to do is fill a cup with water and put it in the refrigerator. The ice cubes that you normally have in the fridge also work.

Once the ice cube is ready, it should be put in the glass with water. This cube will float.

One end of the rope (which would simulate a fishing pole) is placed at the top of the bucket. Sprinkle with salt just at the point where the ice and the rope meet.

You will notice that for a few seconds, the water melts but immediately refreezes.

Wait about 10 seconds and then lift the ice cube very carefully, pulling the string or thread. It will be like catching a frozen fish.

Why does this happen?

What happens in this experiment is that the salt lowers the freezing temperature of the water and, since the ice is already as cold as it can be, it begins to melt.

This melting forms a kind of well on the surface of the ice, which helps to increase the temperature necessary for the freezing point.

The ice then freezes again and the string or thread is trapped inside the ice cube.

Tap water freezes at 32 ° F.

In this video you can see how to do it.

The mirror method

In this experiment the physical principles of reflection and refraction are demonstrated.

When light waves pass through water, a slight bending occurs in the direction of those waves.

And when colliding with the glass of the mirror, there is another deviation that allows the reflection of the colors of the rainbow.

Materials needed for the experiment:

• A small mirror
• A glass of water (in which the mirror can be held)
• A flashlight
• A small room
• A piece of white paper or a white wall

Procedure to follow:

The first thing to do in this case is to place a mirror inside a glass of water.

Then you have to make sure that the room is totally dark.

Now, it is time to turn on a flashlight (or direct the rays of sunlight), and shine the mirror.

A series of mini rainbows will appear on the mirror.

If you place your hand on the base of the glass and direct the light to that point (through the glass with water), the colors of the rainbow will also be seen.

In this video you can see how to do the experiment.

Bends water with static energy

What is demonstrated with this experiment is the operation of static electricity.

The negatively charged particles (electrons) that are naturally in the hair, pass to the comb or the balloon, leaving it with an extra charge of electrons.

In contrast, water is neutral because it has positively and negatively charged particles, but when the object with extra negative charges is brought closer to it, its positive charge reacts and moves the current in that direction.

Materials needed for the experiment:

• A plastic comb (or an inflated balloon)
• A narrow stream of water from a tap
• Dry hair

Procedure to follow:

The first thing to do is open the water tap a little, so that the current that comes out is a few millimeters wide.

Now, the child must slide the comb through the hair at least 10 times

In case a balloon is being used instead of a comb, it should be rubbed from back to front on the hair for a few seconds.

Now, the comb or balloon should be gently approached towards the water stream (without touching it).

You will see how the water bends to reach the comb or balloon.

In this video you can see how to do it.

Without gravity

This experiment will show that it is possible to modify the force of gravity, because the pressure of the air outside a glass is greater than the pressure of the water inside it.

The extra air pressure holds the cardboard in place and the water in the glass.

Materials needed for the experiment:

• A glass of water (overflowing)
• A piece of cardboard

Procedure to follow:

The cardboard should be placed over the mouth of the glass. It is important that no air bubbles get between the water and the cardboard.

Now, the glass is turned upside down. This is done over a sink or a place where it doesn't matter if a little water gets spilled.

Once the glass is turned over, the cardboard is no longer supported by hand.

You will see with amazement that the cardboard does not fall and the water does not spill. There is no gravity!

You can see how to do it in this video.

Recreation of a cloud

It will be shown how a rain cloud is formed with drops of water that result from the collision of cold air with water vapor that has risen after the evaporation of terrestrial bodies of water.

When those clouds accumulate a lot of water, the water returns to the ground as rain.

Materials needed for the experiment:

• 1 jug
• Tap water
• Shaving foam
• Blue food coloring
• Glass dropper

Procedure to follow:

The procedure to follow is to fill the jug with running water. With the shaving cream, a kind of cloud is spread over the surface of the water.

You have to wait a few minutes for the foam to settle and then add a few drops of the blue food coloring.

The foam will start to drip the colorant onto the water, creating a rain effect.

You can see how to do it here.

Walking water

The phenomenon that occurs in the transport of water and nutrients within flowers and plants will be shown.

This happens as a result of capillary action, which is the name given to the process by which a liquid moves through a conduit.

This can also be an opportunity to talk to children about primary and secondary colors.

Materials needed for the experiment:

• 2 paper towels
• 3 transparent glasses
• Yellow and blue food coloring.

Procedure to follow:

All three glasses should be aligned together. In the first glass, you should add water with plenty of blue coloring.

The next glass is left empty and the last one in the row is filled with water and the yellow food coloring is added to it.

It is time to fold the paper towels and place them in the mouth of the glasses; one end is placed in the glass with blue water and the other end is dropped into the empty glass that was placed in the middle.

The operation is repeated in the glass of yellow water; one end of the towel inside and the other end in the empty glass.

In about 30 minutes, the water will pass through the paper towels into the empty glass, and after 2 hours, the middle glass will have a green liquid.

In this video you can see how to do it.

Dry ice bubble

In this experiment it will be shown that carbon dioxide (CO2) in its solid form is dry ice.

When dry ice reaches temperatures above -56.4 ° C (-69.5 ° F), it turns into a gas. It never goes through a liquid state. This is the phenomenon called sublimation.

Putting dry ice in contact with water speeds up the sublimation process and produces clouds of fog.

Materials needed for the experiment:

• Water
• A large bowl with a lip around the top
• A strip of cloth
• Liquid dish soap
• Dry ice (this requires an adult to take safety measures)

Procedure to follow:

Dry ice is placed in a container and a little water is added to it. At this point the scene may resemble that of a Disney movie about witches making a concoction.

Prepare some soapy mixture, adding a little liquid dish soap with water.

Now the piece of cloth is soaked in the soapy mixture and passed around the edge of the container. Then it is passed over the entire top in such a way that bubbles form on the dry ice.

The bubble will start to grow.

In this video you can see it.

Musical water

In this experiment we will show how to create sound waves that travel through water. In the glass with more water the lowest tone will be produced, while in the one with less water the highest tone will be produced.

Materials needed for the experiment:

• 5 or more glasses (glass bottles also work)
• Water
• Wooden stick or pencil

Procedure to follow:

The glasses or jars are lined up in such a way that a row of glasses is formed. To these, water is added in different amounts so that the former has very little water and the latter is full.

With the pencil or another wooden bar, the edge of the glass is struck with less water and then the operation is repeated on the edge of the glass with more water.

Different tones of the sound will be noticed. If done in a specific order, you can get a musical melody.

See how to do it in this video.

Scientific experiments with balloons

Technically speaking, a balloon is nothing more than a container made of a flexible material such as aluminized plastic or rubber. It is normally filled with air but can also be filled with helium.

It is usually used, at least in the West, as the decorative element of the holidays. It also makes a fun toy for children.

Here are some experiments that can be done with balloons that add a more scientific touch to their use.

More space for air

This experiment will show how as the air inside the balloon heats up, it begins to expand in response to the separation that arises between the molecules as they begin to move faster.

This means that the hot air needs more space.

Materials needed for the experiment:

• Empty bottle
• Balloon
• Container with warm water

Procedure to follow:

The balloon should be placed over the mouth of the empty bottle.

This bottle should be placed inside the container with hot water. Let it rest for a few minutes and you will see how the balloon begins to expand.

See in this video how to do it.

Propulsion balloon

This experiment will show that if vinegar and baking soda are combined, a gas is produced that creates a pressure strong enough to blow up a balloon.

Materials needed for the experiment:

• 1 empty plastic bottle
• ½ cup vinegar
• Sodium bicarbonate
• Teaspoon
• Recycling paper
• Permanent marker
• 1 balloon
• 1 scissors
• 1 glue stick

Procedure to follow:

On the clean side of the recycling paper, draw a shirt to stick to the front of the bottle that the 1/2 cup of vinegar will be poured into.

With the permanent marker, draw a face on the balloon and with a small spoon, pour the baking soda into it.

It is time to stretch the neck of the balloon around the neck of the bottle. You have to make sure that the baking soda stays inside the balloon.

Once the balloon is secured in the bottle, the baking soda is dropped into the vinegar.

The balloon (and the face that was drawn on it) will grow.

You can see in this video how to do it.

Experiment with baking soda

Sodium bicarbonate is a type of salt that is formed from carbonic acid. It contains a hydrogen atom that can be replaced by a metal.

Normally, its domestic uses are related to helping in the preparation of fluffy cakes or eliminating heartburn when it is consumed diluted in water (in minimal doses).

It is also used in the preparation of grains (such as beans, for example), to prevent gas in people with irritable bowel.

But here are some experiments that reveal its chemical properties.

Volcano experiment

What you see in this experiment is the chemical reaction between an acid (vinegar) and an alkaline (bicarbonate of soda). They try to neutralize each other.

During such a reaction, carbon dioxide is released, which is a gas. Along with the water and soap, that explains the bubbles.

Materials needed for the experiment:

• 2 tablespoons of baking soda
• 1 tablespoon of liquid soap
• a few drops of red food coloring
• 30 ml of vinegar
• 1 bottle of water

Procedure to follow:

In a cone-shaped container or small prop volcano, add food coloring, soap, water, and baking soda.

All this is mixed and before adding the vinegar, it is set back.

Now you can pour the vinegar and enjoy the artificial volcanic eruption that has just been created.

You can see how to do it in this video.

Magnet experiments

A magnet is a material or body that possesses magnetic force thanks to which it can attract other magnets and ferromagnetic metals.

The magnet can be natural or artificial. The latter can have their magnetism for a determined or indefinite time.

These elements have multiple uses; as a component of electronic equipment or devices, in the magnetic strips that credit and debit cards have, as part of home decoration (in the ornaments that are usually placed in the fridge), etc.

Here are some simple experiments in which children can discover the strength of these objects.

The compass

It will be shown that the earth functions as a huge magnet that attracts all metals to its north pole.

Materials needed for the experiment:

• Water
• 1 bowl, glass or container
• 1 measure
• 2 small pieces of paper or cork
• 2 needle magnets

Procedure to follow:

The first thing to do is float a small sheet of paper in a container or glass of water.

On that piece of paper or cork, you need to put a needle magnet.

Now, you must repeat the operation with the second needle magnet.

The two needles must point in the same direction. Then the earth's magnetism will make the magnet point north.

To be sure, find a reference point that allows you to locate north (your shadow may do the trick), and identify the remaining magnet-needle pointing north.

See in this video how to do it.

Air experiments

Air is the mixture of gases that is in the Earth's atmosphere and that allows human life. Although it is not seen, it is vital for human survival and development.

For years, man has investigated its properties and the forces that affect it to take advantage of it in different fields of industry.

Unfortunately, it is also a natural resource that is being negatively affected by pollution.

In this section you will see some simple experiments that demonstrate the presence and power of air.

The magic ball

In this case, the interaction between the force of the air flow from the dryer and the force of gravity that pushes the ball towards the ground is observed.

The tension between the two forces keeps the ball in the middle and seems to float.

Materials needed for the experiment:

• 1 small ball (like ping pong ball)
• 1 hair dryer

Procedure to follow:

In this simple experiment, it is enough to turn on the hair dryer and direct the air stream upwards, trying not to be hot air.

In the path of that airflow, the ball must be released.

The child will see with amazement how the ball floats.

See in this video how to do it.

The submarine

In this experiment air pressure operates.

When the straw or straw is thrown into the bottle, the air inside makes it float, but when you squeeze it, the interior space compresses and increases the pressure on the straw, sinking it into the water.

When the pressure on the bottle is released, which the child stops squeezing, the air pressure on the straw decreases, it fills with air again and it can float.

Materials needed for the experiment:

• 1 empty soda bottle without the label
• 1 stick of play dough or some clay
• 1 straw or straw
• Water

Procedure to follow:

It begins by cutting a straw to which plasticine is placed at one end, in such a way that that hole is covered.

At the opposite end, a ring of play dough is placed to surround or hug the straw. The goal is to put weight on that end of the straw.

Now three-quarters of water is added to the bottle and it is capped.

The children can then squeeze the bottle to watch the straw sink and release it, so that it returns to the surface of the water to sway. This operation can be repeated as many times as you want.

See in this video how to do it.

Plant experiments

Paint the flowers

Materials needed for the experiment:

• 3 cups with water
• 3 artificial colors
• 3 white flowers

Procedure to follow:

Several drops of the same color should be added to each cup with water, so that each cup has a different color from the other.

The stem of each flower is cut and immersed in the cup of water that has just been colored.

The children will notice that the flowers absorb the water through their stem and progressively change the color of their petals and leaves.

Why does this happen?

This experiment shows the transport function of the stem in plants, and how the nutrients (in this case replaced by colored water) travel through the plants to promote their growth and development.

See in this video how to do it.

The little plant grows, grows

Materials needed for the experiment:

• Ruler or tape measure
• Cucumber, sunflower and basil seeds
• Three pots (can be more if you have enough space and different seeds)
• land
• Water
• Paper
• Pencil or pen

Procedure to follow:

To begin with, soil must be added to the pots. Then the seeds should be placed there (for each pot, a type of plant).

The pots should be located in a space where they receive sunlight.

After a reasonable time, it should be verified which of the pots already has germinated seeds.

Once the first stem emerges, the measurement begins. For this, a ruler or a tape measure is used and the name of the plant, the date and the height are noted.

This operation is repeated every week.

After three weeks, you will begin to notice that each plant has a different growth rate.

Likewise, it will be verified that each type of plant can reach a specific height.

It is an experiment that requires patience so creativity is necessary to encourage children to persevere in measurement.

Perhaps a photoshoot with your favorite plant will help keep it interesting.

Egg experiments

Egg float

Materials needed for the experiment:

• 1 egg
• Water
• 6 tablespoons of salt
• 1 tall glass

Procedure to follow:

The glass should be half filled with water. Then the 6 tablespoons of salt should be added.

Now, add plain water until the glass is almost full.

It's time to put the egg in the water and see what happens. If the plain water was not mixed abruptly with the salt water, the egg will tend to float on the surface of the salt water, about halfway up the glass.

Why does this happen?

In this experiment density is demonstrated.

Salt water has a higher density than ordinary water.

The denser a liquid is, the more likely an object is to float in it.

See in this video how to do it.

Dissolving the shell of an egg

Materials needed for the experiment:

• 1 egg
• A little white vinegar
• 1 thick glass jar with lid (and wide mouth)

Materials needed for the experiment:

Put the egg in the glass jar. For a child, it may be easier to do this by turning the jar slightly so that the egg slides into it.

Now, you can add the vinegar, ensuring that there is enough to cover the egg.

The egg may float, but it will only be for a moment because then it sinks.

In a minute or two, tiny bubbles of carbon dioxide will appear in the eggshell. The jar should be covered and allowed to stand for a week.

Vinegar can be replaced in that time.

After this time, a layer of foam will most likely form on the surface.

It will be seen that the egg has increased a little in size and that its brown color begins to pale.

It is time to remove the egg from the vinegar.

At this point, only a little peel remains that can be cleaned with a gentle rub. If this does not happen, it must be soaked longer in vinegar.

Why does this happen?

In this process, the phenomenon of cellular osmosis is evidenced in which a liquid passes through a semi-permeable cell membrane.

The calcium bicarbonate in the eggshell dissolves in the acidic medium of vinegar. However, vinegar is a mild acid that does not dissolve it immediately without doing so very slowly.

In the process, the calcium bicarbonate is transformed into calcium acetate.

Watch it in this video.

Food experiments

The potato and the arrow

Materials needed for the experiment:

• Several straws or rigid plastic straws
• 1 raw potato

Procedure to follow:

To start this experiment, it is necessary to do a test first: hold the cigarette without covering the hole at its upper end and throw it towards the potato as if trying to stab it.

It will be a useless effort because the potato cannot be penetrated. And in case it is achieved, it will be only by a few millimeters.

Now, it's time for the real experiment:

You try to do the same with the potato, but this time you cover the hole at the top of the straw with your thumb.

This time you should drill a larger space in the potato.

Why does this happen?

What happens is that by covering the hole in the cigarette, the air inside it is compressed and this serves as an impulse to reach the potato with more force.

A force that manages to penetrate the skin of the potato and its pulp.

See in this video how to do the experiment.

Orange float

Materials needed for the experiment:

• 1 orange
• 1 deep bowl
• Water

Procedure to follow:

You need to start by pouring the water into the container. Then the orange is thrown into the water.

The next part of the experiment is to do the same, but the second time it should be done after peeling the orange peel.

What this experiment reveals is that the orange has air in its peel, which contributes to increasing the density of the water as it floats on its surface.

By peeling the orange, however, the density of the orange increases and the denser material sinks into the water.

See in this video how to do the experiment.

Milk art

Materials needed for the experiment:

• A bowl
• ½ cup of milk
• Dish soap
• Cotton swab (cutex or swab)
• Various food coloring

Procedure to follow:

The milk is poured into the bowl and wait a few minutes for it to settle and the surface of the milk to stabilize.

Add drops of different colored food coloring to different spots in the milk.

Dampen one end of the swab with some of the soap and dab over the colored drops.

You will see how fun figures are formed and you can enjoy works of art.

It should be noted that this milk will not be suitable for consumption after this experiment.

Why does this happen?

This reaction is due to the fact that the milk has a high fat content and the liquid from the colorants floats on the fat.

The dish soap cuts the bonds in the fats and separates them, and the color that was added makes that separation more visible.

There are variations of this experiment when the temperature of the milk is changed and when different types of milk are used.

Another thing that can be done is to add pepper to the milk before touching its surface with the swab dipped in soap.

Watch this video how to do it.

Magnetic Cereal

Materials needed for the experiment:

• Cereal
• Neodymium magnet
• 1 transparent bottle
• Water

Procedure to follow:

You have to fill the bottle with water up to a third and add the cereal. The bottle is capped and shaken vigorously.

The cereal is left "soaking" overnight in such a way that it softens and breaks.

When the cereal is completely wet and in smaller pieces, the magnet is placed on the outside of the bottle, ensuring that there is more liquid at the point where the magnet is.

The bottle is then turned so that the water is not directly under the magnet.

Little by little, remove the magnet and you will see the iron pieces stuck to the bottle.

Why does this happen?

There is some iron content in cereals, and when it is broken into smaller pieces or soaked in water, that content is more exposed.

The magnet will attract those metallic traces with its magnetism.

See in this video how to do it.

Lava lamp

Materials needed for the experiment:

• Water
• A clear plastic bottle
• Vegetable oil
• Food coloring
• Alka seltzer

Procedure to follow:

The plastic bottle is filled with water until it is a quarter full. A funnel can help you do this without spilling a lot of liquid.

Now, the bottle is finished filling with vegetable oil.

The mixture is allowed to stand for a few minutes until both liquids separate.

Little by little, about twelve drops of the food coloring are added. The color of that dye can be any.

The food coloring will mix with the water and turn into a liquid in the “scientist kid's” favorite color.

Now, the Alka-Seltzer tablet (5 or 6) is cut into pieces, and one of those pieces is thrown into the bottle with the mixture.

The effervescence will turn the bottle into a lava lamp.

Why does this happen?

Water and oil don't mix very well. In fact, due to its density, the oil stays at the top of the bottle.

The dye goes straight to the bottom and mixes with the water. The Alka-Seltzer releases bubbles of carbon dioxide.

These bubbles rise to the top loaded with colored water. The reaction ends when the gas reaches the surface and releases the water from the bubble.

Every time an Alka-Seltzer tablet is added to the bottle, the same reaction will be seen. And shaking the bottle back and forth will prolong the reaction time.

See in this video how to do the experiment.

Experiments with different materials

Miniature rockets with tea bag

Materials needed for the experiment:

• A tea bag
• A lighter
• A fire resistant tray
• A garbage bag

Procedure to follow:

One end of the tea bag is cut off and its contents emptied. With the freshly cut bag, a cylinder is formed and placed on the tray.

Now, and with the help and supervision of an adult, the upper part of the tea bag is lit. It should take off.

Why does this happen?

This happens because the flow of hot air blows the small mass of the tea bag away.

See in this video how to do it.

Liquid layers

• Some juice
• Vegetable oil
• Alcohol
• A transparent container

Procedure to follow:

The container is taken and the juice is poured. On top of the juice, the vegetable oil is added little by little but in such a way that it slides along the walls of the container.

Now, it is time to gently pour the alcohol. Alcohol can be pure or colored.

It will be seen that the liquids are separated into three layers.

Why does this happen?

This happens because the substances in this experiment have different densities. The result can be more aesthetic if the liquids are colored separately.

Watch this video how to do it.

Tornado in a bottle

• Two transparent bottles
• A tube
• Some water

Procedure to follow:

The water is poured into one of the bottles and connected to the other through the nozzle with the tube (it can be a pvc or plastic tube).

The liquid is spun in the bottle located at the top. As the liquid begins to drain into the other bottle, a vortex is generated.

Why does this happen?

This happens because as the water circulates downwards, the air is forced to go upwards.

This process generates a spiral tornado.

If you want to add a different touch, you can add glitter, food coloring or lamp oil.

You can see a variant of this experiment in this video.

Overweight gummy bears

Materials needed for the experiment:

• A bag of gummy bears
• 4 glasses
• A teaspoon of salt
• One teaspoon of baking soda.
• Measuring tape
• Kitchen weight
• Pencil and paper (to take note of physical changes during the experiment).

Procedure to follow:

You have to take the glasses and add 50 milliliters of water to each of them.

One, it is left alone with water; vinegar is added to another; to another add the teaspoon of salt; and to the fourth, add the teaspoon of baking soda.

Now, each teddy bear is measured and weighed and that data is noted, identifying it very well so that it can be detected if a change occurs or not.

Then, each bear is placed in a different glass and there they are left to soak overnight.

At dawn, the bears are removed from the glasses and left to dry.

Now, each bear is measured and weighed a second time and the data is compared.

Why does this happen?

Here, too, the phenomenon of osmosis is noted.

Check it out in this video.

Tightrope forks

Materials needed for the experiment:

• Two forks.
• A toothpick
• A long glass.
• A lighter.

Procedure to follow:

You must start by coupling the two forks.

Then, the stick is passed through the first hole of one of the forks and is removed through the second hole of the other as if it were a tissue.

Now, put the forks with the stick interlaced to the edge of the glass. That is, the toothpick will rest on the edge of the glass, while supporting the weight of the forks in a delicate balance.

It is time to light a fire at the end of the toothpick that is towards the inside of the glass (with supervision and help from an adult).

The fire will consume the toothpick, but the forks will balance.

Why does this happen?

This is the balance provided by the location of the center of mass.

In this case, the center of gravity is below the fulcrum.

Watch this video how to do it.