just scroll down this page, I don’t have the links hooked………
Balloons and Fire
Balloon Blow Up
Balloon rocket for your room!
Bubble Bomb
COLLAPSING CAN
EGG SUCK
Exploding lunch bag!
Float Soap Bubbles
Film canister rocket!
Go with the flow
Hard and Soft Water
HOMEMADE SLIME
Ocean in a Bottle
Rock candy!
Rubber Bands
Static electricity
A glass of colored liquid into a froth that overflows
VOLCANO!
For more idea’s go here to the following links:
The Science Explorer
ScienceBob.com
Science Experiments You Can Do!
Real Time Experiments!
Quick and Easy Activities
Home Experiments
Do Science! – Science tricks, experiments and activities
Basic science for kids, childrens science projects & experiments
The Collapsing Can
We are so accustomed to the pressure of the air around us that we don’t even notice it. However, the air pressure is large enough to crush a soda can. You can see the air crush a can in this experiment.
For this experiment you will need:
an empty aluminum soft-drink can
a 2- or 3-liter (2- or 3-quart) saucepan
a pair of kitchen tongs
Fill the saucepan with cold water. Put 15 milliliters (1 tablespoon) of water into the empty soft-drink can. Heat the can on the kitchen stove to boil the water. When the water boils, a cloud of condensed vapor will escape from the opening in the can. Allow the water to boil for about 30 seconds. Using the tongs, grasp the can and quickly invert it and dip it into the water in the pan. The can will collapse almost instantaneously.
What caused the can to collapse? When you heated the can you caused the water in it to boil. The vapor from the boiling water pushed the air out of the can. When the can was filled with water vapor, you cooled it suddenly by inverting it is water. Cooling the can caused the water vapor in the can to condense, leaving the can empty. When the can was empty, the pressure of the air outside crushed it.
A can is crushed when the pressure outside is greater than the pressure inside, and the pressure difference is greater than the can is able to withstand. You can crush an open aluminum can with your hand. When you squeeze on the can, the pressure outside becomes greater than the pressure inside. If you squeeze hard enough the can collapses. Usually, the air pressure inside an open can is the same as the pressure outside. However, in this experiment, the air was driven out of the can and replaced by water vapor. When the water vapor condensed, the pressure inside the can became much less than the air pressure outside. Then the air outside crushed the can.
When the water vapor inside the can condensed, the can was empty. You may have expected the water in the pan to fill the can through the hole in the can. Some water from the pan may do this. However, the water cannot flow into the can fast enough to fill the can before the air outside crushes it.
CAUTION: Do not heat the can over high heat or heat the can when it is empty. This may cause the ink on the can to burn or the aluminum to melt.
Static electricity
Static electricity can be a problem whenever the humidity is low. It causes shocks and makes dust stick to surfaces, and it can literally make your hair stand on end. In this experiment, you will see that it also can move things around.
For this experiment you will need:
a nylon comb
a water faucet
Adjust the faucet to produce a small stream of water. The stream should be about 1.5 millimeters (1/16 inch) in diameter.
Run the comb through your hair several times. Slowly bring the teeth of the comb near the stream of water, about 8 to 10 centimeters (3 or 4 inches) below the faucet. When the teeth of the comb are about an inch or less away from the stream, the stream will bend toward the comb.
Move the comb closer to the stream. How does the distance between the stream and the comb affect how much the stream bends?
Run the comb through your hair several more times. Does the comb bend the stream more now?
Change the size of the stream by adjusting the faucet. Does the size of the stream affect how much the stream bends?
If you have other combs, you can try these to see if some bend the stream more than others.
Static electricity is the accumulation of an electrical charge in an object. The electrical charge develops when two objects are rubbed against one another. When the objects are rubbed together, some electrons (charged components of atoms) jump from one object to the other. The object that loses the electrons becomes positively charged, while the object that they jump to becomes negatively charged. The nature of the objects has a large effect on how many electrons move. This determines how large an electrical charge accumulates in the objects. Hair and nylon are particularly good at acquiring charge when they are rubbed together.
A charged object attract small particles, such as dust. The charge in the object causes a complementary charge to develop in something close to it. The complementary charge is attracted to the charged object. If the complementary charge forms on something tiny, such as dust particles, these tiny particles move to the charged object. This is why your television screen becomes dusty faster than the television cabinet. When a television operates, electrons fly from the back to the screen. These electrons cause the screen to become charged. The charge on the screen attracts dust.
The comb attracts the stream of water in the same way. The charge on the comb attracts the molecules of water in the stream. Because the molecules in the stream can be moved easily, the stream bends toward the comb.
When you comb your hair with a nylon comb, both the comb and your hair become charged. The comb and your hair acquire opposite charges. Because the individual hairs acquire the same charge, they repel each other. Perhaps you noticed that after running the nylon comb through your hair, the hairs on your head stood on end. This is a result of your hairs repelling each other because they are charged.
Static electricity is more of a problem when humidity is low. When humidity is high, most surfaces are coated with a thin film of water. When objects coated by a film of water are rubbed together, the water prevents electrons from jumping between the objects.
Hard and Soft Water
Tap water in many parts of the country contains minerals that can interfere with the cleaning ability of detergents. That’s why water softeners are popular in these locations. Water softeners remove these minerals. In this experiment, you will make “hard” water from distilled water, which contains no minerals, and is therefore “soft.” You can then compare the sudsing ability of a detergent in soft and hard water.
For this experiment you will need:
500 milliliters (2 cups) distilled water
5 milliliters (1 teaspoon) epsom salts
2 empty and cleaned 2-liter plastic soft-drink containers, with screw caps
several drops of liquid dishwashing detergent (not the kind for automatic dishwashers)
Pour 250 milliliters (1 cup) of distilled water into each of the empty soft-drink bottles. Add 5 milliliters (1 teaspoon) of epsom salts to one of the bottles. Swirl the bottle until the epsom salts dissolve. Add several drops of liquid dish detergent to both bottles. Seal the bottles with their caps. Shake both bottles. A large amount of suds will form in the bottle without epsom salts. Far fewer suds will form in the bottle containing the epsom salts.
The suds formed in this experiment are made of tiny bubbles. The bubbles are formed when air is trapped in a film of liquid. The air is trapped when it is shaken into the water. The film of liquid surrounding each bubble is a mixture of water and detergent. The molecules of detergent form a sort of framework that holds the water molecules in place in the film. If there were no detergent, the bubbles would collapse almost as soon as they are formed. You can see what this would look like by repeating the experiment, but leaving out the detergent.
This experiment will not produce suds if detergent for a dishwashing machine is used. (Try it and see.) No suds are formed because automatic dishwasher detergent is formulated so that it does not form suds. Suds create problems in a dishwasher. They interfere with the movements of the washing arms, and they are dicult to rinse o of the dishes.
The minerals that make water hard usually contain calcium and magnesium. In this experiment, you made water hard by adding epsom salt, which is magnesium sulfate. Calcium and magnesium in water interfere with the cleaning action of soap and detergent. They do this by combining with soap or detergent and forming a scum that does not dissolve in water. Because they react with soap and detergent, they remove the soap and detergent, thereby reducing the eectiveness of these cleaning agents. This could be overcome by adding more soap or detergent. However, the scum that is formed can adhere to what is being washed, making it appear dingy.
Water can be softened in a number of ways. An automatic water softener connected to water supply pipes removes magnesium and calcium from water and replaces them with sodium. Sodium does not react with soap or detergents. If you don’t have an automatic water softener, you can still soften laundry water by adding softeners directly to the wash water. These softeners combine with calcium and magnesium, preventing the minerals from forming a soap scum.
Balloons and Fire
Balloons are rather fragile things. You know that they must be kept away from sharp objects. The also need to be kept away from flames. A fire can weaken the rubber and cause it to burst. However, in this experiment you will find out how you can hold a balloon directly in a flame without breaking the balloon.
For this experiment you will need:
two round balloons, not inflated
several matches
water
Inflate one of the balloons and tie it closed. Place 60 milliliters (* cup) of water in the other balloon, and then inflate it and tie it shut.
Light a match and hold it under the first balloon. Allow the flame to touch the balloon. What happens? The balloon breaks, perhaps even before the flame touches it.
Light another match. Hold it directly under the water in the second balloon. Allow the flame to touch the balloon. What happens with this balloon? The balloon doesn’t break. You may even see a black patch of soot form on the outside of the balloon above the flame.
Why does the balloon with no water break in the flame? The flame heats whatever is placed in it. It heats the rubber of both balloons. The rubber of the balloon without water becomes so hot, that it becomes too weak to resist the pressure of the air inside the balloon.
How does the balloon with water in it resist breaking in the flame? When water inside the balloon is placed in the flame, the water absorbs most of the heat from the flame. Then, the rubber of the balloon does not become very hot. Because the rubber does not become hot, it does not weaken, and the balloon does not break.
Water is a particularly good absorber of heat. It takes a lot of heat to change the temperature of water. It takes ten times as much heat to raise the temperature of 1 gram of water by 1C than it does to raise the temperature of 1 gram of iron by the same amount. This is why it takes so long to bring a teakettle of water to the boil. On the other hand, when water cools, it releases a great deal of heat. This is why areas near oceans or other large bodies of water do not get as cold in winter as areas at the same latitude further inland.
CAUTION: Be careful when handling matches to avoid burning yourself or causing accidental fires.
Float Soap Bubbles
Nearly everyone has enjoyed playing with soap bubbles. These fragile spheres of soap film filled with air are both beautiful and captivating. However, few people have observed them closely or at length, because soap bubbles are fragile and very light. When you blow soap bubbles out of doors, the slightest breeze carries them away. If you blow them indoors in still air, the bubbles soon settle onto a surface and break. However, because they are very light, soap bubbles will float on a gas that is only slightly more dense than the air that fills them. Such a gas is carbon dioxide. When soap bubbles settle into a container of carbon dioxide, the bubbles float on the carbon dioxide and can be examined closely. Under this close examination, soap bubbles reveal many properties that are not otherwise easily seen.
To float soap bubbles, you will need the following materials:
soap bubble solution
a wand for blowing soap bubbles
a large transparent container with an open top (an empty 38-liter [10-gallon] aquarium works nicely)
125 milliliters (* cup) of baking soda (sodium bicarbonate)
250 milliliters (1 cup) vinegar
shallow glass dish to fit inside large container (such as a glass baking dish)
Set the large container on a table away from drafts and where you can easily look through its sides. Place the glass dish inside on the bottom of the large transparent container. Put 125 milliliters (* cup) of baking soda in the glass dish. Pour 250 milliliters (1 cup) of vinegar into the dish with the baking soda. The mixture of soda and vinegar will immediately start to fizz as they react and form carbon dioxide gas. Carbon dioxide is more dense than air and so it will be held in the large container as long as it is not disturbed by drafts of air over the container. Because carbon dioxide is colorless, you cannot see it inside the container. However, you will soon be able to detect its presence with soap bubbles.
After the fizzing in the dish has subsided (about a minute), gently blow several soap bubbles over the opening of the large container, so that they settle into the container. This may take a bit of practice. (Do not blow directly into the container, you will blow the carbon dioxide out of it.) When a soap bubble settles into the container it will not sink to the bottom, as it would in air. Instead, it will float on the surface of the invisible carbon dioxide in the container.
While the bubble is floating on the carbon dioxide in the container, you can observe the soap bubble closely. Note what the bubble looks like. What color is the bubble? Can you see more than one color on the bubble? Do the colors change? Notice the size of the bubble. Does its size change? Observe the position of the bubble. Does it stay at the same level in the container? Does it rise or sink?
When you have finished observing the bubbles, dispose of the mixture in the glass dish by rinsing it down the drain with water.
The colors of a soap bubble come from reflections of the white light that falls on the bubble. White light, such as from the sun or from a light bulb, contains light of all colors. Light has waves, and the length of the wave, from crest to crest, determines the color of the light. When light reflects from a bubble, some of each wave reflects at the outside surface of the soap film. Some light travels through the soap film, and reflects from the inside surface of the film.
Interference between waves occurs whenever waves travel through the same space. Interference occurs when two rocks are tossed near each other into a lake. Circular waves on the surface of the water spread out from where each rock entered the water. Where the crests of two waves meet, interference between the waves causes the motion of the surface of the water to increase. Where a crest and a valley meet, interference reduces the motion of the water’s surface. Similar interference can occur in waves of light.
Waves of light reflected from the inner and outer surfaces of the film of a soap bubble can interfere with each other. Where the crests of the light waves reflected from the inner and outer surfaces of the film meet, the intensity of the light increases. If the crest of a wave reflected from the inner surface meets the valley of a wave from the outer surface, the intensity of the light will be diminished. Whether the crest of a wave meets another crest or a valley is determined by the length of the wave and by the thickness of the film. If the thickness of the film is a multiple of the wavelength of the light, the crests of waves reflected from the inner surface will meet the crests of waves reflected from the outer surfaces. If the thickness of the film is an odd multiple of half the wavelength, the crests of the waves reflected from the inner surface will meet the valleys of the waves reflected from the outer surface. Because the thickness of the film varies and the wavelength of the light determines its color, different areas of the bubble will have different colors. The colors of a film of oil on a wet parking lot are produced in the same way as the colors of a soap bubble.
If your soap bubbles remained floating on the carbon dioxide for more than a minute, you may have noticed that the bubbles were slowly becoming larger. You also may have noticed that the bubbles slowly sank into the container. Both the growth and the sinking of the bubbles is a result of the same process. When you blew the bubble, it was filled with air. When it settled into the container of carbon dioxide, the bubble was surrounded by this gas. The bubble grows because carbon dioxide moves into the bubble (through the soap film) faster than air moves out of the bubble. Carbon dioxide can move through the soap film more quickly than air, because it is more soluble in water than is air. (Water is the major component of the bubble-soap solution.) As the amount of carbon dioxide in the bubble increases, the bubble becomes heavier and sinks lower into the carbon dioxide in which it is floating.
Rubber Bands
Just about everyone has used rubber bands, but few people have taken the time to observe the less obvious properties of these everyday objects. In this activity you will examine the thermal properties of rubber, that is, the behavior of rubber as it relates to heat, a form of energy.
In the first experiment you will attempt to detect heat flow into or out of a rubber band. To do this, you need a rather sensitive heat detector. Fortunately, you have such a detector with you at all times. Surely, you’ve felt the heat of a flame or the cold of an ice cube. Therefore, you know that your skin is sensitive to heat flow. In this experiment, you will detect heat flow using some of your most sensitive skin, that on your forehead or on your lips.
Place your thumbs through the heavy rubber band, one on each end. Without stretching the band, hold it to your forehead or lip. Does the band feel cool or warm or about the same as your skin? Repeat the test several times until you are sure of the result.
Move the rubber band slightly away from your face, so it is not touching your skin. Quickly stretch the band about as far as you can and, holding it in the stretched position, touch it again to your forehead or lip. Does it feel warmer or cooler or about the same as it did when it was relaxed?
Move the stretched rubber band away from you face. Quickly let it relax to its original size and again hold it to your skin. Does it feel warm or cool?
Repeat the stretching and testing, and relaxing and testing several times until you are sure of the results.
An object feels cool or cold to you when heat flows from your skin to the object. Conversely, an object feels warm or hot when heat flows from the object into your skin. If the stretched rubber band feels cool, then it absorbs heat from your skin. If it feels warm, then it gives off heat to your skin. If the band feels neither warm nor cool, then there is no detectable heat flow. These three cases can be represented as follows:
Case 1. Relaxed Band + Heat Stretched Band
Case 2. Relaxed Band Stretched Band + Heat
Case 3. Relaxed Band Stretched Band (No Heat)
Which of these three cases best describes what you observed?
There is another way to test which of the three statements is correct. We can see what happens to the length of a rubber band if we heat or cool it.
Hang one end of the rubber band from the wall or ceiling and suspend a weight from the other end of the rubber band. (What you use for a weight will depend on what is available. The weight should be heavy enough to stretch the rubber band, but not so heavy that it is likely to break the band. For example, hang the band over a door knob and suspend a hammer from the band.)
Heat the rubber band with a hair dryer. Start the dryer and, when it has warmed up, turn its heat on the stretched rubber band. Does the stretched rubber band become longer or shorter when it is heated?
Does this observation agree with what you found in the first part of the experiment? Doing an experiment several ways and checking for agreement in the results is an important strategy in science.
When rubber is heated it behaves differently than most familiar materials. Most materials expand when they are heated. Consider the liquid in a thermometer. The thermometer works because the liquid expands when its temperature increases. Similarly, a wire made of metal, such as copper, becomes longer as it gets hotter. The expansion of metals with increasing temperature is the principle behind the functioning of home thermostats and of jumping discs.
Whether a material expands or contracts when it is heated can be ascribed to a property of the material called its entropy. The entropy of a material is a measure of the orderliness of the molecules that make up the material. When the molecules are arranged in an ordered fashion, the entropy of the material is low. When the molecules are in a disordered arrangement, the entropy is high. (An ordered arrangement can be thought of as coins in a wrapper, while a disordered one as coins in a tray.) When a material is heated, its entropy increases because the orderliness of its molecules decreases. This occurs because as a material is heated, its molecules move about more energetically. In materials made up of small, compact molecules, e.g., the liquid in a thermometer, as the molecules move about more, they push their neighboring molecules away. Rubber, on the other hand, contains very large, threadlike molecules. When rubber is heated, the sections of the molecules move about more vigorously. In order for one part of the molecule to move more vigorously as it is heated, it must pull its neighboring parts closer. To visualize this, think of a molecule of the stretched rubber band as a piece of string laid out straight on a table. Heating the stretched rubber band causes segments of the molecules to move more vigorously, which can be represented by wiggling the middle of the string back and forth. As the middle of the string moves, the ends of the string get closer together. In a similar fashion, the molecules of rubber become shorter as the rubber is heated, causing the stretched rubber band to contract
Turn a glass of colored liquid into a froth that overflows
With just a few household chemicals you can turn a glass of colored liquid into a froth that overflows its container.
For this experiment you will need:
15 cm3 (1 tablespoon) of baking soda (sodium bicarbonate)
15 cm3 (1 tablespoon) of laundry detergent
about 180 milliliters (3/4 cup) of water
about 60 milliliters (1/4 cup) of vinegar
several drops of food coloring (optional)
a 400-milliliter (12-ounce) drinking glass
a waterproof (plastic or metal) tray
a teaspoon
Place the drinking glass on the tray. Put 15 cm3 baking soda and 15 cm3 laundry detergent to the glass. Add 180 mL of water and a few drops of optional food coloring. Gently stir the mixture to mix the contents of the glass. To display and observe the fizzing and foaming, quickly pour the vinegar into the glass. The mixture will foam up and over the top of the glass, covering the tray with a froth of tiny bubbles.
To produce a color change when the vinegar is added to the mixture in the glass, you can substitute some red cabbage juice for the optional food coloring. The experiment titled “Exploring Acids and Bases with Red Cabbage” gives instructions on how to prepare some red cabbage juice. With red cabbage juice, the mixture will chage color from blue-green before adding vinegar to red-orange after the vinegar is added. For a different color change, try grape juice.
In this experiment, the fizz is produced by a chemical reaction between baking soda and vinegar. Baking soda and vinegar react, and one of the products of the reaction is carbon dioxide gas. This gas forms bubbles that are surrounded by the liquid. The laundry detergent makes the bubbles last longer, and a foam is produced. The volume of the gas produced and trapped in the foam is much greater than the glass can hold, so some of it spills over the top of the glass.
Baking soda is sodium bicarbonate. Vinegar contains acetic acid dissolved in water. Sodium barcarbonate reacts with most acids. The products of the reaction with vinegar are carbon dioxide gas, sodium acetate, and water.
The reaction of sodium bicarbonate to form carbon dioxide gas is the basis of its use as a levening agent in baking. Cakes are solid foams. The foam is produced when bubbles of carbon dioxide from the reaction of sodium bicarbonate are trapped in the batter. As the cake bakes, the batter dries, and the trapped bubbles of carbon dioxide form the holes in the cake.
Make a balloon rocket for your room!
A Balloon Rocket uses air pressure to move forward. The air is forced out of the balloon quickly which creates thrust to move the rocket forward.
To make a working balloon rocket in your own room, you will need:
1 balloon (round ones will work, but the longer “airship” balloons work best)
1 long piece of kite string (about 10-15 feet long)
1 plastic straw
tape
Here’s what to do:
Tie one end of the string to a chair, door knob, or other support.
Put the other end of the string through the straw.
Pull the string tight and tie it to another support in the room.
Blow up the balloon (but don’t tie it) Pinch the end of the balloon and tape it to the straw. You’re ready for launch.
Let go and watch the rocket fly! You can experiment to figure out how to make the rocket go farther and faster.
HOMEMADE SLIME!
Step 1:
*
Mix together 3/4 cup warm water, 1 cup glue and several drops of green food coloring in the first bowl.
Step 2:
*
In the second bowl, mix together 4 teaspoons borax and 1 1/3 cups warm water.
Step 3:
*
Pour the contents of the first bowl into the second, but don’t stir. Let it sit for 1 minute, then lift the now-congealed slime out of the bowl.
Step 4:
*
Divide slime so that each child has a piece to play with. The glue in slime can make it stick to certain fabrics. To minimize accidents, give each little monster a zip-top bag to store it in.
Tips:
SAFETY NOTE: Since borax is toxic in large doses, be sure to keep the slime away from kids younger than age three.
Rock candy!
THIS EXPERIMENT REQUIRES ADULT HELP
IT DEALS WITH VERY HOT LIQUIDS
BE SMART AND BE SAFE – ONLY DO THIS WITH ADULT HELP
You will need
15cm piece of string
A pencil
A paper clip (or large plastic bead)
1 cup of water
2 cups of sugar
A glass jar
What to do
Tie the 15 cm piece of string to the middle of the pencil.
Tie the paper clip (or bead) onto the end of the string.
Put the pencil across the top of a jar so that the string hangs down the middle of the jar. If it hangs down too far, roll the string around the pencil until the string is not touching the sides or bottom of the jar. The string will act as a seed for the crystal. Any type of jar will do, but canning jars, pint size are especially nice, they will endure the hot temperatures. Tall skinny olive jars are also nice because they don’t use up so much of the liquid.
Now that the string and pencil are ready remove them from the jar and put them aside
Get a helpful adult!
Pour the water into a pan and bring it to boil.
Pour about 1/4 cup of sugar into the boiling water, stirring until it dissolves.
Keep adding more and more sugar, each time stirring it until it dissolves, until no more will dissolve. This will take time and patience and it will take longer for the sugar to dissolve each time.Be sure you don’t give up too soon.
Have your friendly ADULT carefully pour the hot sugar solution into the jars to the top. Then submerge the paper clip and string into the sugar solution. Be sure the string hangs down in the middle of the jar.
Allow the jar to cool and put it someplace where it will not be disturbed.
Now just wait. The sugar crystals will grow for the next few weeks. When you mixed the water and sugar you made a SUPER SATURATED SOLUTION. This means that the water could only hold the sugar if both were very hot. As the water cools the sugar “comes out” of the solution back into sugar crystals on your string. The string and paper clip act as a “seed” that they start to grow on. With some luck and patience you will have a tasty scientific treat! Enjoy!
HOME-MADE VOLCANO!
To make an erupting volcano you will need:
A volcano – Talk to an art teacher about making a volcano out of paper mache or plaster. If you’re in a hurry to make your volcano, use a mound of dirt outside.
A container that 35mm film comes in.
Red and yellow food coloring (optional)
Vinegar
Liquid dish washing soap
What to do:
Go outside
Put the film canister into the volcano at the top
Add two spoonfuls of baking soda
Add about a spoonful of soap
Add about 3 drops of the red and yellow food coloring
Now for the eruption!:
Add about an ounce of the vinegar into the container and watch what happens.
A VOLCANO is produced over thousands of years as heat a pressure build up. That aspect of a volcano is very difficult to recreate in a home experiment. However this volcano will give you an idea of what it might look like when a volcano erupts flowing lava. This is a classic experiment in which a CHEMICAL reaction can create the appearance of a PHYSICAL volcano eruption. You should look at pictures of volcanos to be familiar with the different types. (A SHIELD volcano, for example is the most common kind of volcano, and yet few people know about them) The reaction will bubble up and flow down the side like a real volcano (only much faster!) Look for videos of volcanos erupting and be sure that you understand how heat and pressure work to really make volcanos erupt. Have fun!
The exploding lunch bag!
A whole new way to use sandwich bags!
You will need:
One small zip-lock bag – small freezer bags work best.
Baking soda
Warm water
Vinegar
Measuring cup
A tissue
What to do:
1. Go outside – or at least do this in the kitchen sink.
2. Put 1/4 cup of pretty warm water into the bag.
3. Add 1/2 cup of vinegar to the water in the bag.
3. Put 3 teaspoons of baking soda into the middle of the tissue
4. Wrap the the baking soda up in the tissue by folding the tissue around it.
5. You will have to work fast now – partially zip the bag closed but leave enough space to add the baking soda packet. Put the tissue with the baking soda into the bag and quickly zip the bag completely closed.
6. Put the bag in the sink or down on the ground (outside) and step back. The bag will start to expand, and expand, and if all goes well…POP!
Cool huh? Nothing like a little chemistry to to add fun to a boring afternoon. What happens inside the bag is actually pretty interesting – the baking soda and the vinegar eventually mix (the tissue buys you some time to zip the bag shut) When they do mix, you create an ACID-BASE reaction and the two chemicals work together to create a gas, (carbon dioxide – the stuff we breathe out) well it turns out gasses need a lot of room and the carbon dioxide starts to fill the bag, and keeps filling the bag until the bag can no longer hold it any more and, POP! Be sure to clean up well and recycle those plastic bags…have fun!
Build a film canister rocket!
Build and launch a rocket that goes 10 feet in the air!
You will need:
One 35mm plastic film canister (the container most 35mm film comes in)
The lid that come with the 35mm film canister
One antacid tablet (such as Alka-Seltzer – Get this from your parents)
water
What to do:
1. Go outside.
2. Remove the lid from the film canister and put one antacid tablet in the container.
3. Add a teaspoon of water to the container.
3. Do the next 2 steps quickly – put the cap on and make sure that is on tightly
4. Quickly put the canister on the ground CAP SIDE DOWN and STEP BACK at least 2 meters.
5. About 10 seconds later, you will hear a POP! and the film canister will launch into the air!
6. If it does not launch, wait at least 30 second before examining the canister. Usually the cap is not on tight enough.
TIP – The white plastic film canisters usually work better than the black canisters with the gray tops.
SO HOW DOES IT WORK?
When you add the water it starts to dissolve the alkaselzer tablet. This creates a gas call carbon dioxide. It also creates pressure inside the film canister. As more gas is made, more pressure builds up until the cap it blasted down and
The Collapsing Can
We are so accustomed to the pressure of the air around us that we don’t even notice it. However, the air pressure is large enough to crush a soda can. You can see the air crush a can in this experiment.
For this experiment you will need:
an empty aluminum soft-drink can
a 2- or 3-liter (2- or 3-quart) saucepan
a pair of kitchen tongs
Fill the saucepan with cold water. Put 15 milliliters (1 tablespoon) of water into the empty soft-drink can. Heat the can on the kitchen stove to boil the water. When the water boils, a cloud of condensed vapor will escape from the opening in the can. Allow the water to boil for about 30 seconds. Using the tongs, grasp the can and quickly invert it and dip it into the water in the pan. The can will collapse almost instantaneously.
What caused the can to collapse? When you heated the can you caused the water in it to boil. The vapor from the boiling water pushed the air out of the can. When the can was filled with water vapor, you cooled it suddenly by inverting it is water. Cooling the can caused the water vapor in the can to condense, leaving the can empty. When the can was empty, the pressure of the air outside crushed it.
A can is crushed when the pressure outside is greater than the pressure inside, and the pressure difference is greater than the can is able to withstand. You can crush an open aluminum can with your hand. When you squeeze on the can, the pressure outside becomes greater than the pressure inside. If you squeeze hard enough the can collapses. Usually, the air pressure inside an open can is the same as the pressure outside. However, in this experiment, the air was driven out of the can and replaced by water vapor. When the water vapor condensed, the pressure inside the can became much less than the air pressure outside. Then the air outside crushed the can.
When the water vapor inside the can condensed, the can was empty. You may have expected the water in the pan to fill the can through the hole in the can. Some water from the pan may do this. However, the water cannot flow into the can fast enough to fill the can before the air outside crushes it.
CAUTION: Do not heat the can over high heat or heat the can when it is empty. This may cause the ink on the can to burn or the aluminum to melt.
Static electricity
Static electricity can be a problem whenever the humidity is low. It causes shocks and makes dust stick to surfaces, and it can literally make your hair stand on end. In this experiment, you will see that it also can move things around.
For this experiment you will need:
a nylon comb
a water faucet
Adjust the faucet to produce a small stream of water. The stream should be about 1.5 millimeters (1/16 inch) in diameter.
Run the comb through your hair several times. Slowly bring the teeth of the comb near the stream of water, about 8 to 10 centimeters (3 or 4 inches) below the faucet. When the teeth of the comb are about an inch or less away from the stream, the stream will bend toward the comb.
Move the comb closer to the stream. How does the distance between the stream and the comb affect how much the stream bends?
Run the comb through your hair several more times. Does the comb bend the stream more now?
Change the size of the stream by adjusting the faucet. Does the size of the stream affect how much the stream bends?
If you have other combs, you can try these to see if some bend the stream more than others.
Static electricity is the accumulation of an electrical charge in an object. The electrical charge develops when two objects are rubbed against one another. When the objects are rubbed together, some electrons (charged components of atoms) jump from one object to the other. The object that loses the electrons becomes positively charged, while the object that they jump to becomes negatively charged. The nature of the objects has a large effect on how many electrons move. This determines how large an electrical charge accumulates in the objects. Hair and nylon are particularly good at acquiring charge when they are rubbed together.
A charged object attract small particles, such as dust. The charge in the object causes a complementary charge to develop in something close to it. The complementary charge is attracted to the charged object. If the complementary charge forms on something tiny, such as dust particles, these tiny particles move to the charged object. This is why your television screen becomes dusty faster than the television cabinet. When a television operates, electrons fly from the back to the screen. These electrons cause the screen to become charged. The charge on the screen attracts dust.
The comb attracts the stream of water in the same way. The charge on the comb attracts the molecules of water in the stream. Because the molecules in the stream can be moved easily, the stream bends toward the comb.
When you comb your hair with a nylon comb, both the comb and your hair become charged. The comb and your hair acquire opposite charges. Because the individual hairs acquire the same charge, they repel each other. Perhaps you noticed that after running the nylon comb through your hair, the hairs on your head stood on end. This is a result of your hairs repelling each other because they are charged.
Static electricity is more of a problem when humidity is low. When humidity is high, most surfaces are coated with a thin film of water. When objects coated by a film of water are rubbed together, the water prevents electrons from jumping between the objects.
Hard and Soft Water
Tap water in many parts of the country contains minerals that can interfere with the cleaning ability of detergents. That’s why water softeners are popular in these locations. Water softeners remove these minerals. In this experiment, you will make “hard” water from distilled water, which contains no minerals, and is therefore “soft.” You can then compare the sudsing ability of a detergent in soft and hard water.
For this experiment you will need:
500 milliliters (2 cups) distilled water
5 milliliters (1 teaspoon) epsom salts
2 empty and cleaned 2-liter plastic soft-drink containers, with screw caps
several drops of liquid dishwashing detergent (not the kind for automatic dishwashers)
Pour 250 milliliters (1 cup) of distilled water into each of the empty soft-drink bottles. Add 5 milliliters (1 teaspoon) of epsom salts to one of the bottles. Swirl the bottle until the epsom salts dissolve. Add several drops of liquid dish detergent to both bottles. Seal the bottles with their caps. Shake both bottles. A large amount of suds will form in the bottle without epsom salts. Far fewer suds will form in the bottle containing the epsom salts.
The suds formed in this experiment are made of tiny bubbles. The bubbles are formed when air is trapped in a film of liquid. The air is trapped when it is shaken into the water. The film of liquid surrounding each bubble is a mixture of water and detergent. The molecules of detergent form a sort of framework that holds the water molecules in place in the film. If there were no detergent, the bubbles would collapse almost as soon as they are formed. You can see what this would look like by repeating the experiment, but leaving out the detergent.
This experiment will not produce suds if detergent for a dishwashing machine is used. (Try it and see.) No suds are formed because automatic dishwasher detergent is formulated so that it does not form suds. Suds create problems in a dishwasher. They interfere with the movements of the washing arms, and they are dicult to rinse o of the dishes.
The minerals that make water hard usually contain calcium and magnesium. In this experiment, you made water hard by adding epsom salt, which is magnesium sulfate. Calcium and magnesium in water interfere with the cleaning action of soap and detergent. They do this by combining with soap or detergent and forming a scum that does not dissolve in water. Because they react with soap and detergent, they remove the soap and detergent, thereby reducing the eectiveness of these cleaning agents. This could be overcome by adding more soap or detergent. However, the scum that is formed can adhere to what is being washed, making it appear dingy.
Water can be softened in a number of ways. An automatic water softener connected to water supply pipes removes magnesium and calcium from water and replaces them with sodium. Sodium does not react with soap or detergents. If you don’t have an automatic water softener, you can still soften laundry water by adding softeners directly to the wash water. These softeners combine with calcium and magnesium, preventing the minerals from forming a soap scum.
Balloons and Fire
Balloons are rather fragile things. You know that they must be kept away from sharp objects. The also need to be kept away from flames. A fire can weaken the rubber and cause it to burst. However, in this experiment you will find out how you can hold a balloon directly in a flame without breaking the balloon.
For this experiment you will need:
two round balloons, not inflated
several matches
water
Inflate one of the balloons and tie it closed. Place 60 milliliters (* cup) of water in the other balloon, and then inflate it and tie it shut.
Light a match and hold it under the first balloon. Allow the flame to touch the balloon. What happens? The balloon breaks, perhaps even before the flame touches it.
Light another match. Hold it directly under the water in the second balloon. Allow the flame to touch the balloon. What happens with this balloon? The balloon doesn’t break. You may even see a black patch of soot form on the outside of the balloon above the flame.
Why does the balloon with no water break in the flame? The flame heats whatever is placed in it. It heats the rubber of both balloons. The rubber of the balloon without water becomes so hot, that it becomes too weak to resist the pressure of the air inside the balloon.
How does the balloon with water in it resist breaking in the flame? When water inside the balloon is placed in the flame, the water absorbs most of the heat from the flame. Then, the rubber of the balloon does not become very hot. Because the rubber does not become hot, it does not weaken, and the balloon does not break.
Water is a particularly good absorber of heat. It takes a lot of heat to change the temperature of water. It takes ten times as much heat to raise the temperature of 1 gram of water by 1C than it does to raise the temperature of 1 gram of iron by the same amount. This is why it takes so long to bring a teakettle of water to the boil. On the other hand, when water cools, it releases a great deal of heat. This is why areas near oceans or other large bodies of water do not get as cold in winter as areas at the same latitude further inland.
CAUTION: Be careful when handling matches to avoid burning yourself or causing accidental fires.
Float Soap Bubbles
Nearly everyone has enjoyed playing with soap bubbles. These fragile spheres of soap film filled with air are both beautiful and captivating. However, few people have observed them closely or at length, because soap bubbles are fragile and very light. When you blow soap bubbles out of doors, the slightest breeze carries them away. If you blow them indoors in still air, the bubbles soon settle onto a surface and break. However, because they are very light, soap bubbles will float on a gas that is only slightly more dense than the air that fills them. Such a gas is carbon dioxide. When soap bubbles settle into a container of carbon dioxide, the bubbles float on the carbon dioxide and can be examined closely. Under this close examination, soap bubbles reveal many properties that are not otherwise easily seen.
To float soap bubbles, you will need the following materials:
soap bubble solution
a wand for blowing soap bubbles
a large transparent container with an open top (an empty 38-liter [10-gallon] aquarium works nicely)
125 milliliters (* cup) of baking soda (sodium bicarbonate)
250 milliliters (1 cup) vinegar
shallow glass dish to fit inside large container (such as a glass baking dish)
Set the large container on a table away from drafts and where you can easily look through its sides. Place the glass dish inside on the bottom of the large transparent container. Put 125 milliliters (* cup) of baking soda in the glass dish. Pour 250 milliliters (1 cup) of vinegar into the dish with the baking soda. The mixture of soda and vinegar will immediately start to fizz as they react and form carbon dioxide gas. Carbon dioxide is more dense than air and so it will be held in the large container as long as it is not disturbed by drafts of air over the container. Because carbon dioxide is colorless, you cannot see it inside the container. However, you will soon be able to detect its presence with soap bubbles.
After the fizzing in the dish has subsided (about a minute), gently blow several soap bubbles over the opening of the large container, so that they settle into the container. This may take a bit of practice. (Do not blow directly into the container, you will blow the carbon dioxide out of it.) When a soap bubble settles into the container it will not sink to the bottom, as it would in air. Instead, it will float on the surface of the invisible carbon dioxide in the container.
While the bubble is floating on the carbon dioxide in the container, you can observe the soap bubble closely. Note what the bubble looks like. What color is the bubble? Can you see more than one color on the bubble? Do the colors change? Notice the size of the bubble. Does its size change? Observe the position of the bubble. Does it stay at the same level in the container? Does it rise or sink?
When you have finished observing the bubbles, dispose of the mixture in the glass dish by rinsing it down the drain with water.
The colors of a soap bubble come from reflections of the white light that falls on the bubble. White light, such as from the sun or from a light bulb, contains light of all colors. Light has waves, and the length of the wave, from crest to crest, determines the color of the light. When light reflects from a bubble, some of each wave reflects at the outside surface of the soap film. Some light travels through the soap film, and reflects from the inside surface of the film.
Interference between waves occurs whenever waves travel through the same space. Interference occurs when two rocks are tossed near each other into a lake. Circular waves on the surface of the water spread out from where each rock entered the water. Where the crests of two waves meet, interference between the waves causes the motion of the surface of the water to increase. Where a crest and a valley meet, interference reduces the motion of the water’s surface. Similar interference can occur in waves of light.
Waves of light reflected from the inner and outer surfaces of the film of a soap bubble can interfere with each other. Where the crests of the light waves reflected from the inner and outer surfaces of the film meet, the intensity of the light increases. If the crest of a wave reflected from the inner surface meets the valley of a wave from the outer surface, the intensity of the light will be diminished. Whether the crest of a wave meets another crest or a valley is determined by the length of the wave and by the thickness of the film. If the thickness of the film is a multiple of the wavelength of the light, the crests of waves reflected from the inner surface will meet the crests of waves reflected from the outer surfaces. If the thickness of the film is an odd multiple of half the wavelength, the crests of the waves reflected from the inner surface will meet the valleys of the waves reflected from the outer surface. Because the thickness of the film varies and the wavelength of the light determines its color, different areas of the bubble will have different colors. The colors of a film of oil on a wet parking lot are produced in the same way as the colors of a soap bubble.
If your soap bubbles remained floating on the carbon dioxide for more than a minute, you may have noticed that the bubbles were slowly becoming larger. You also may have noticed that the bubbles slowly sank into the container. Both the growth and the sinking of the bubbles is a result of the same process. When you blew the bubble, it was filled with air. When it settled into the container of carbon dioxide, the bubble was surrounded by this gas. The bubble grows because carbon dioxide moves into the bubble (through the soap film) faster than air moves out of the bubble. Carbon dioxide can move through the soap film more quickly than air, because it is more soluble in water than is air. (Water is the major component of the bubble-soap solution.) As the amount of carbon dioxide in the bubble increases, the bubble becomes heavier and sinks lower into the carbon dioxide in which it is floating.
Rubber Bands
Just about everyone has used rubber bands, but few people have taken the time to observe the less obvious properties of these everyday objects. In this activity you will examine the thermal properties of rubber, that is, the behavior of rubber as it relates to heat, a form of energy.
In the first experiment you will attempt to detect heat flow into or out of a rubber band. To do this, you need a rather sensitive heat detector. Fortunately, you have such a detector with you at all times. Surely, you’ve felt the heat of a flame or the cold of an ice cube. Therefore, you know that your skin is sensitive to heat flow. In this experiment, you will detect heat flow using some of your most sensitive skin, that on your forehead or on your lips.
Place your thumbs through the heavy rubber band, one on each end. Without stretching the band, hold it to your forehead or lip. Does the band feel cool or warm or about the same as your skin? Repeat the test several times until you are sure of the result.
Move the rubber band slightly away from your face, so it is not touching your skin. Quickly stretch the band about as far as you can and, holding it in the stretched position, touch it again to your forehead or lip. Does it feel warmer or cooler or about the same as it did when it was relaxed?
Move the stretched rubber band away from you face. Quickly let it relax to its original size and again hold it to your skin. Does it feel warm or cool?
Repeat the stretching and testing, and relaxing and testing several times until you are sure of the results.
An object feels cool or cold to you when heat flows from your skin to the object. Conversely, an object feels warm or hot when heat flows from the object into your skin. If the stretched rubber band feels cool, then it absorbs heat from your skin. If it feels warm, then it gives off heat to your skin. If the band feels neither warm nor cool, then there is no detectable heat flow. These three cases can be represented as follows:
Case 1. Relaxed Band + Heat Stretched Band
Case 2. Relaxed Band Stretched Band + Heat
Case 3. Relaxed Band Stretched Band (No Heat)
Which of these three cases best describes what you observed?
There is another way to test which of the three statements is correct. We can see what happens to the length of a rubber band if we heat or cool it.
Hang one end of the rubber band from the wall or ceiling and suspend a weight from the other end of the rubber band. (What you use for a weight will depend on what is available. The weight should be heavy enough to stretch the rubber band, but not so heavy that it is likely to break the band. For example, hang the band over a door knob and suspend a hammer from the band.)
Heat the rubber band with a hair dryer. Start the dryer and, when it has warmed up, turn its heat on the stretched rubber band. Does the stretched rubber band become longer or shorter when it is heated?
Does this observation agree with what you found in the first part of the experiment? Doing an experiment several ways and checking for agreement in the results is an important strategy in science.
When rubber is heated it behaves differently than most familiar materials. Most materials expand when they are heated. Consider the liquid in a thermometer. The thermometer works because the liquid expands when its temperature increases. Similarly, a wire made of metal, such as copper, becomes longer as it gets hotter. The expansion of metals with increasing temperature is the principle behind the functioning of home thermostats and of jumping discs.
Whether a material expands or contracts when it is heated can be ascribed to a property of the material called its entropy. The entropy of a material is a measure of the orderliness of the molecules that make up the material. When the molecules are arranged in an ordered fashion, the entropy of the material is low. When the molecules are in a disordered arrangement, the entropy is high. (An ordered arrangement can be thought of as coins in a wrapper, while a disordered one as coins in a tray.) When a material is heated, its entropy increases because the orderliness of its molecules decreases. This occurs because as a material is heated, its molecules move about more energetically. In materials made up of small, compact molecules, e.g., the liquid in a thermometer, as the molecules move about more, they push their neighboring molecules away. Rubber, on the other hand, contains very large, threadlike molecules. When rubber is heated, the sections of the molecules move about more vigorously. In order for one part of the molecule to move more vigorously as it is heated, it must pull its neighboring parts closer. To visualize this, think of a molecule of the stretched rubber band as a piece of string laid out straight on a table. Heating the stretched rubber band causes segments of the molecules to move more vigorously, which can be represented by wiggling the middle of the string back and forth. As the middle of the string moves, the ends of the string get closer together. In a similar fashion, the molecules of rubber become shorter as the rubber is heated, causing the stretched rubber band to contract
Turn a glass of colored liquid into a froth that overflows
With just a few household chemicals you can turn a glass of colored liquid into a froth that overflows its container.
For this experiment you will need:
15 cm3 (1 tablespoon) of baking soda (sodium bicarbonate)
15 cm3 (1 tablespoon) of laundry detergent
about 180 milliliters (3/4 cup) of water
about 60 milliliters (1/4 cup) of vinegar
several drops of food coloring (optional)
a 400-milliliter (12-ounce) drinking glass
a waterproof (plastic or metal) tray
a teaspoon
Place the drinking glass on the tray. Put 15 cm3 baking soda and 15 cm3 laundry detergent to the glass. Add 180 mL of water and a few drops of optional food coloring. Gently stir the mixture to mix the contents of the glass. To display and observe the fizzing and foaming, quickly pour the vinegar into the glass. The mixture will foam up and over the top of the glass, covering the tray with a froth of tiny bubbles.
To produce a color change when the vinegar is added to the mixture in the glass, you can substitute some red cabbage juice for the optional food coloring. The experiment titled “Exploring Acids and Bases with Red Cabbage” gives instructions on how to prepare some red cabbage juice. With red cabbage juice, the mixture will chage color from blue-green before adding vinegar to red-orange after the vinegar is added. For a different color change, try grape juice.
In this experiment, the fizz is produced by a chemical reaction between baking soda and vinegar. Baking soda and vinegar react, and one of the products of the reaction is carbon dioxide gas. This gas forms bubbles that are surrounded by the liquid. The laundry detergent makes the bubbles last longer, and a foam is produced. The volume of the gas produced and trapped in the foam is much greater than the glass can hold, so some of it spills over the top of the glass.
Baking soda is sodium bicarbonate. Vinegar contains acetic acid dissolved in water. Sodium barcarbonate reacts with most acids. The products of the reaction with vinegar are carbon dioxide gas, sodium acetate, and water.
The reaction of sodium bicarbonate to form carbon dioxide gas is the basis of its use as a levening agent in baking. Cakes are solid foams. The foam is produced when bubbles of carbon dioxide from the reaction of sodium bicarbonate are trapped in the batter. As the cake bakes, the batter dries, and the trapped bubbles of carbon dioxide form the holes in the cake.
Make a balloon rocket for your room!
A Balloon Rocket uses air pressure to move forward. The air is forced out of the balloon quickly which creates thrust to move the rocket forward.
To make a working balloon rocket in your own room, you will need:
1 balloon (round ones will work, but the longer “airship” balloons work best)
1 long piece of kite string (about 10-15 feet long)
1 plastic straw
tape
Here’s what to do:
Tie one end of the string to a chair, door knob, or other support.
Put the other end of the string through the straw.
Pull the string tight and tie it to another support in the room.
Blow up the balloon (but don’t tie it) Pinch the end of the balloon and tape it to the straw. You’re ready for launch.
Let go and watch the rocket fly! You can experiment to figure out how to make the rocket go farther and faster.
HOMEMADE SLIME!
Step 1:
Mix together 3/4 cup warm water, 1 cup glue and several drops of green food coloring in the first bowl.
Step 2:
In the second bowl, mix together 4 teaspoons borax and 1 1/3 cups warm water.
Step 3:
Pour the contents of the first bowl into the second, but don’t stir. Let it sit for 1 minute, then lift the now-congealed slime out of the bowl.
Step 4:
Divide slime so that each child has a piece to play with. The glue in slime can make it stick to certain fabrics. To minimize accidents, give each little monster a zip-top bag to store it in.
Tips:
SAFETY NOTE: Since borax is toxic in large doses, be sure to keep the slime away from kids younger than age three.
Rock candy!
THIS EXPERIMENT REQUIRES ADULT HELP
IT DEALS WITH VERY HOT LIQUIDS
BE SMART AND BE SAFE – ONLY DO THIS WITH ADULT HELP
You will need
15cm piece of string
A pencil
A paper clip (or large plastic bead)
1 cup of water
2 cups of sugar
A glass jar
What to do
Tie the 15 cm piece of string to the middle of the pencil.
Tie the paper clip (or bead) onto the end of the string.
Put the pencil across the top of a jar so that the string hangs down the middle of the jar. If it hangs down too far, roll the string around the pencil until the string is not touching the sides or bottom of the jar. The string will act as a seed for the crystal. Any type of jar will do, but canning jars, pint size are especially nice, they will endure the hot temperatures. Tall skinny olive jars are also nice because they don’t use up so much of the liquid.
Now that the string and pencil are ready remove them from the jar and put them aside
Get a helpful adult!
Pour the water into a pan and bring it to boil.
Pour about 1/4 cup of sugar into the boiling water, stirring until it dissolves.
Keep adding more and more sugar, each time stirring it until it dissolves, until no more will dissolve. This will take time and patience and it will take longer for the sugar to dissolve each time.Be sure you don’t give up too soon.
Have your friendly ADULT carefully pour the hot sugar solution into the jars to the top. Then submerge the paper clip and string into the sugar solution. Be sure the string hangs down in the middle of the jar.
Allow the jar to cool and put it someplace where it will not be disturbed.
Now just wait. The sugar crystals will grow for the next few weeks. When you mixed the water and sugar you made a SUPER SATURATED SOLUTION. This means that the water could only hold the sugar if both were very hot. As the water cools the sugar “comes out” of the solution back into sugar crystals on your string. The string and paper clip act as a “seed” that they start to grow on. With some luck and patience you will have a tasty scientific treat! Enjoy!
HOME-MADE VOLCANO!
To make an erupting volcano you will need:
A volcano – Talk to an art teacher about making a volcano out of paper mache or plaster. If you’re in a hurry to make your volcano, use a mound of dirt outside.
A container that 35mm film comes in.
Red and yellow food coloring (optional)
Vinegar
Liquid dish washing soap
What to do:
Go outside
Put the film canister into the volcano at the top
Add two spoonfuls of baking soda
Add about a spoonful of soap
Add about 3 drops of the red and yellow food coloring
Now for the eruption!:
Add about an ounce of the vinegar into the container and watch what happens.
A VOLCANO is produced over thousands of years as heat a pressure build up. That aspect of a volcano is very difficult to recreate in a home experiment. However this volcano will give you an idea of what it might look like when a volcano erupts flowing lava. This is a classic experiment in which a CHEMICAL reaction can create the appearance of a PHYSICAL volcano eruption. You should look at pictures of volcanos to be familiar with the different types. (A SHIELD volcano, for example is the most common kind of volcano, and yet few people know about them) The reaction will bubble up and flow down the side like a real volcano (only much faster!) Look for videos of volcanos erupting and be sure that you understand how heat and pressure work to really make volcanos erupt. Have fun!
The exploding lunch bag!
A whole new way to use sandwich bags!
You will need:
One small zip-lock bag – small freezer bags work best.
Baking soda
Warm water
Vinegar
Measuring cup
A tissue
What to do:
1. Go outside – or at least do this in the kitchen sink.
2. Put 1/4 cup of pretty warm water into the bag.
3. Add 1/2 cup of vinegar to the water in the bag.
3. Put 3 teaspoons of baking soda into the middle of the tissue
4. Wrap the the baking soda up in the tissue by folding the tissue around it.
5. You will have to work fast now – partially zip the bag closed but leave enough space to add the baking soda packet. Put the tissue with the baking soda into the bag and quickly zip the bag completely closed.
6. Put the bag in the sink or down on the ground (outside) and step back. The bag will start to expand, and expand, and if all goes well…POP!
Cool huh? Nothing like a little chemistry to to add fun to a boring afternoon. What happens inside the bag is actually pretty interesting – the baking soda and the vinegar eventually mix (the tissue buys you some time to zip the bag shut) When they do mix, you create an ACID-BASE reaction and the two chemicals work together to create a gas, (carbon dioxide – the stuff we breathe out) well it turns out gasses need a lot of room and the carbon dioxide starts to fill the bag, and keeps filling the bag until the bag can no longer hold it any more and, POP! Be sure to clean up well and recycle those plastic bags…have fun!
Build a film canister rocket!
Build and launch a rocket that goes 10 feet in the air!
You will need:
One 35mm plastic film canister (the container most 35mm film comes in)
The lid that come with the 35mm film canister
One antacid tablet (such as Alka-Seltzer – Get this from your parents)
water
What to do:
1. Go outside.
2. Remove the lid from the film canister and put one antacid tablet in the container.
3. Add a teaspoon of water to the container.
3. Do the next 2 steps quickly – put the cap on and make sure that is on tightly
4. Quickly put the canister on the ground CAP SIDE DOWN and STEP BACK at least 2 meters.
5. About 10 seconds later, you will hear a POP! and the film canister will launch into the air!
6. If it does not launch, wait at least 30 second before examining the canister. Usually the cap is not on tight enough.
TIP – The white plastic film canisters usually work better than the black canisters with the gray tops.
SO HOW DOES IT WORK?
When you add the water it starts to dissolve the alkaselzer tablet. This creates a gas call carbon dioxide. It also creates pressure inside the film canister. As more gas is made, more pressure builds up until the cap it blasted down and the rocket is blasted up. This is actually how a real rocket works whether it is in outer space or here in the earth’s atmosphere. You can improve the rocket by adding fins and a nose cone that you can make out of paper. If you like this experiment, try the Exploding Lunch Bag. Be safe and have fun!
Go with the flow:
A clear plastic bottle or jar with a tight-fitting, screw-on cap or lid (a clear plastic water bottle works great)
Liquid hand soap that has glycol stearate in it (The brand we used is Colgate-Palmolive’s Softsoap, but any brand of liquid soap with glycol stearate — not glycol distearate — will work; check the ingredients on the label.
**Water
**Food coloring
**Clear tape
**Fill the bottle or jar about 1/4 full with liquid soap. Add a drop or two of food coloring. The coloring will make the swirls easier to see.
**Turn on your faucet so you have just a trickle of water. Use that to fill up the rest of the bottle. (If you run the water too hard, you’ll get foam.) Make sure that the water fills the bottle all the way to the very top.
**Screw the cap on the bottle. Turn the bottle upside-down a few times to mix the soap and water. If you get foam, take the cap off and trickle some more water into the bottle. The foam will run over the edge. Recap the bottle tightly.
**Dry the bottle and the cap, then wrap clear tape around it so the bottle won’t leak.
**Twirl the bottle slowly. What do you see? What happens when you stop twirling the bottle? What happens if you spin it quickly?
**Try shaking the bottle up and down or side to side. What different patterns do you see inside the bottle?
**If the liquid inside the bottle looks like it’s all one solid color, just twirl or shake it again to make more patterns. If the cap on the bottle is sealed, Go with the Flow can last for years
(Note: If you find a really pretty plastic bottle or jar, you can give this to someone as a gift!)
Why can I see patterns in the water?
Normally, you can’t see how the water is moving inside a full jar of water. Water that’s moving in one direction looks the same as water that’s moving in another direction. But glycol stearate, the chemical that gives some liquid hand soaps a pearly look, lets you see patterns flow in water.
What kinds of patterns can I see in my jar?
Who cares about these patterns?
When you turn the bottle slowly, you’ll probably see smooth streaks in the water. When layers of water are moving slowly and smoothly past each other, you get this pattern, which scientists call laminar flow.
When you suddenly stop turning the bottle, or when you turn it very fast, you may see lots of swirls and wavy patterns. When one layer of water moves rapidly past another layer of water, it causes turbulence, which you see as swirly patterns.
When people design airplanes, cars, boats, golf balls, and other things that move through air or water, they study the patterns blowing air or flowing water makes as the object moves through it. Differences in the flow of air or water can affect how well an airplane flies, how much mileage a car gets per gallon, how fast a boat can go, or how far a golf ball will fly when you smack it with a club.
Ocean in a Bottle
Also referred to as a Pet Wave
What you will need
**rubbing alcohol
**mineral spirits
**food coloring
**water bottle
Fill half of the bottle with rubbing alcohol.
Put two to three drops of food coloring into the bottle and shake.
Fill remainder of the bottle with mineral spirits.
Put top on – Do not Shake.
Hold bottle horizontally until clear, then raise and lower ends to create waves.
EGG SUCK
Make an egg go through an unlikely opening.
Ingredients:
– A peeled hard-boiled egg (extra-large size/grade egg).
– Glass bottle with a wide opening (the opening should be just a little smaller than the width of the egg). Many apple juice bottles work well for this demonstration. Also, make sure the bottle is dry.
– Matches
– An audience to show how cool this trick is.
Warning:
Adult supervision is required. This experiment involves flames.
The Recipe:
1) Place the egg on top of the bottle and show others that it will not fit through the opening.
2) Light two matches and get them burning.
3) Lift the egg from the bottle and drop the burning matches into the bottle. Immediately replace the egg.
4) The egg might jump up and down a little, but don’t touch it…just watch what happens next.
Balloon Blow Up
1 medium-sized round balloon
1 pop bottle
1 tablespoon of baking soda
1/3 cup of vinegar
funnel
Funnel the baking soda into the balloon. Pour vinegar into the bottle. Stretch the balloon opening over the mouth of the bottle and hold to seal the balloon tightly to the bottle. Raise the top of the balloon to spill the baking soda into the bottle.
When the soda mixes with the vinegar, a gas forms and inflates the balloon.
Bubble Bomb
**water
**measuring cup
**zipper-lock plastic sandwich bags
**paper towel
**tablespoon
**baking soda
**vinegar
**Figure out where you want to explode your Bubble Bomb. Sometimes the bags make a mess when they pop, so you may want to experiment outside. If it’s a rainy day, you can explode your Bubble Bombs in the bathtub or sink.
**It’s very important to use a bag without holes. To test the zipper-lock bag, put about half a cup of water into it. Zip it closed and turn it upside down. If no water leaks out, you can use that bag. Unzip it and pour out the water. If the bag leaks, try another one. Keep testing bags until you find one that doesn’t leak.
**Tear a paper towel into a square that measures about 5 inches by 5 inches. Put 1 1/2 tablespoons of baking soda in the center of the square, then fold the square as shown in the picture, with the baking soda inside. This is your “time-release packet.”
**Pour into your plastic bag:
**1/2 cup of vinegar
**1/4 cup of warm water
**Now here’s the tricky part. You need to drop the time-release packet into the vinegar and zip the bag closed before the fizzing gets out of control.
**You can zip the bag halfway closed, then stuff the packet in and zip the bag closed the rest of the way in a hurry. Or you can put the time-release packet into the mouth of the bag and hold it up out of the vinegar by pinching the sides of the bag. Zip the bag closed and then let the packet drop into the vinegar.
**One way or another, get the packet in the vinegar and zip the bag closed.
**Shake the bag a little, put it in the sink or on the ground, and stand back! The bag will puff up dramatically and pop with a bang.
Why does the Bubble Bomb explode?
The bubbles in the Bubble Bomb are filled with carbon dioxide, a gas that forms when the vinegar (an acid) reacts with the baking soda (a base).
If you’ve ever made a cake or baked a loaf of quick bread (the kind that doesn’t use yeast), you’ve already done some experimenting with the bubbles that come from an acid-base reaction. Most cakes and quick breads rise because of bubbles in their batter. Those bubbles, like the ones in your Bubble Bomb, are created by the chemical reaction of an acid and a base.
Take a look at a recipe for quick bread. If the recipe includes baking soda but no baking powder, it will probably also include an ingredient that’s acidic-such as buttermilk, sour milk, or orange juice.
Quick-bread recipes may call for baking powder in addition to or instead of baking soda. Baking powder is made by combining baking soda with an acidic ingredient, such as tartaric acid or calcium acid phosphate. When you add water to baking powder, it will fizz as the acid and base interact. In fact, if you ever run out of baking powder, you can make your own by mixing two teaspoons cream of tartar (it provides the acid), one teaspoon of baking soda (it’s the base), and a half-teaspoon of salt.
Try using a different size of zipper-lock plastic bag. What do you think might happen? Do you think you’ll need to use more baking soda, vinegar, and water to make the bag explode? Try it and see.
In the original experiment, we asked you to use warm water. Try using cold water or hot water. Does changing the temperature change your results? How?
The first time you tried this, you mixed the vinegar with water. Try doing the experiment again with just vinegar. How did this change your experiment?
Instead of using paper towel, make your “time release packet” using a different kind of paper, like toilet paper, tissue paper or notebook paper. What happened?
Any baked goods that rise rely on carbon dioxide bubbles to get the job done. You can make these bubbles either by using yeast or by using the acid-base reaction like you did in the experiment.
Yeast is a one-celled fungus which converts sugar to carbon dioxide gas. Because this process takes a while, bakers use yeast in doughs that they leave alone for several hours.
Another method that cooks use to make something rise is a combination of baking soda and an acidic ingredient, like orange juice or buttermilk. This is the same kind of chemical reaction that took place in your bubble bomb.
Next time someone you know is baking, check the recipe to see if you can figure out what ingredients make the bubbles that make the cake or bread or cookies rise.
