balloons full

8/13/2019 Balloons Full

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AIR

Balloons

OBJECTIVES:

Students will be able to:

Explain how balloons are inated

Describe the basic properties

of balloons

CURRICULUM CONNECTIONS

BY GRADE:

Individual curriculum connections

are listed for each activity.

LIST OF ACTIVITIES:

Yeast-Inated Balloons

Fireghting CO2Balloons

Windbag

Balloon Shish Kebab

Ball in the Balloon Gag

Balloon and Cup Attraction

Fireproof Balloon

Balloon-boarding

Balloon Hovercraft

Balloon Popping Relay

NOT JUST A LOT OF HOT AIR!

INTRODUCTION

Most children have played with balloons, but few have thought about the chemical and

physical concepts involved in balloon production and use. In the activities that follow,

students explore balloon properties and their use in demonstrating various scientic concepts.

BACKGROUND

A balloon can be dened as an inatable exible bag lled with a gas, such as helium,

hydrogen, nitrous oxide, oxygen, or air. Modern balloons are made from materials such

as rubber, latex, polychloroprene, metalized plastic or a nylon fabric.

Long before there was something as stretchy as rubber, balloons existed. In the pre-rubber

era, balloons came from animal bladders. A pigs bladder was inated by Galileo in anexperiment to measure the weight of air. Inated animal bladders were used in play by

Indian and Inuit children. Most of the bladders were from sea animals.

The Aztecs are thought to be the very rst people in history to make balloon animals out

of the bowels of cats to be presented to the gods as a sacrice. The bowels were carefully

cleaned, turned inside out, and sewn with a special vegetable thread whose main property

was that it stuck to itself when left to dry in the sun, and this produced an almost airtight seal.

The bowels were then twisted and air was blown into them after each twist.

The rst rubber balloons were made by Professor Michael Faraday in 1824 for use in his

experiments with hydrogen, at the Royal Institution of Great Britain in London. Faraday made

his balloons by cutting two round sheets of raw rubber, called caoutchouc (French word for

rubber), laying them one on top of the other and pressing their edges together. The tackyrubber welded automatically, and the inside of the balloon was rubbed with our to prevent

the opposing surfaces joining together.

Toy balloons were introduced by rubber manufacturer Thomas Hancock the following year

(1825) in the form of a do-it-yourself kit consisting of a bottle of rubber solution and a

condensing syringe.

Vulcanized toy balloons, which were unaffected by changes in temperature, were rst

manufactured by J.G. Ingram of London in 1847 and can be regarded as the prototype

of modern toy balloons.

In 1931, the Tillotson Rubber Company achieved another milestone in balloon technology:they created the rst modern latex balloon made from the sap of a rubber tree. Before that,

the balloon-making process was difcult and dangerous due to the use of solvent-dissolved

rubber, similar to rubber cement. This new balloon, shaped like a cats head with pointed

ears and a whisker-printed face, was also possibly the worlds rst novelty-shaped and

printed balloon.

RESOURCES.SCIENCEWORLD.CA


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The natural rubber latex used today comes from the sap of the rubber tree, Hevea

Brasiliensis, which grows in Malaysia. This sap looks like milk and is exported in large

ocean tanker ships. Once removed from the tree, the sap is called latex. To make thissuitable for balloon production, curing agents, accelerators, oil, color, and water must

be added. Next, the modied latex is put into an open tank, and the balloon mold,

which is in the shape of a balloon, is dipped.

A video on how balloons are made is available in the Resources section.

A SAFETY NOTE:

Some people are violently allergic to latex, particularly people who work in health care,

people with spina bida, and those who have had multiple surgeries.


AIR

Balloons

NOTES


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REFERENCES

Balloon HQ | Balloon Twisting

http://www.balloonhq.com Wikipedia | Balloon Modelling

http://en.wikipedia.org/wiki/Balloon_modelling

Wikipedia | Balloon

http://en.wikipedia.org/wiki/Balloon

Wikipedia | Pig Bladder | Pictures of children playing with inated pig bladders

http://en.wikipedia.org/wiki/Pig_bladder

Balloon History

The Great Balloon Game Book and More Balloon Activities By Arnold E. Grummer.

Original Edition Published by Greg Markim, Inc., Appleton, Wisconsin, 1987

ISBN 0-938251-00-7

Yeast-Air Balloon

The Accidental Scientist | Science of Cooking | Yeast-air Balloons

http://www.exploratorium.edu/cooking/bread/activity-yeast.html CO

2Heavier than Air Experiment

Columbia Scientic | Kid Science |search CO2

http://www.columbiascientific.com/kids-science-experiments/

Bernoulli Bag (Windbag)

Steve Spangler Science | Windbag The Bernoulli Bag

http://www.stevespanglerscience.com/experiment/00000062

Bernoullis Principle

U.S. Centennial of Flight Commission | Bernoullis Principle

http://www.centennialofight.gov/essay/Dictionary/bernoulli/DI9.htm

Physics.org | Balloon Kebabs

http://www.physics.org/interact/physics-to-go/balloon-kebabs/index.html

Balloon & Cup Experiment

SFU | Physics Department | Outreach Activities Site | Air Pressure | Gravity Defying Cups

http://www.sfu.ca/physics/outreach/activities/airpressure.htm

Fireproof Balloon

Steve Spangler Science | Experiment | Fire Water Coolest Conductor of Heat

http://www.stevespanglerscience.com/experiment/re-water-coolest-conductor-of-heat

Genuine Ideas | Toy Ideas | Balloon Hovercraft

http://www.genuineideas.com/ToyIdeas/balloonhovercraft.html

OTHER RESOURCES

How Products are Made | Balloon

http://www.madehow.com/Volume-2/Balloon.html

You Tube | Steve Spangler Science | Windbags

http://www.youtube.com/watch?v=UujAMPv3y-A Steve Spangler Science | SearchBalloon Experiments

http://www.stevespanglerscience.com

You Tube | Questacon Science Squad | CD Balloon Hovercraft

http://www.youtube.com/watch?v=Uh2oAlm9P_E

You Tube | How Balloons are Manufactured

http://www.youtube.com/watch?v=y8oWkx1PhUY&feature=related


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5/19

ACTIVITY 1:YEAST INFLATED BALLOONS 510 MINUTES

FOR ASSEMBLY, 2030 MINUTES FOR RESULTS (EXTENSION

ACTIVITIES COULD TAKE 12 CLASSES)

Students use yeast to explore CO2production by living organisms. This is an excellent

opportunity for students to design their own experiments to determine which variables

affect the yeasts ability to produce CO2.

Yeast is a fungal microorganism that feeds on sugar and produces carbon dioxide (CO2)

plus ethanol. As the yeast feeds on the sugar it produces carbon dioxide gas. This process

is known as fermentation.

The trapped CO2accumulates inside the balloon, slowly inating it.

A very similar process happens as bread rises. Carbon dioxide from yeast lls thousands

of balloon-like bubbles in the dough. This is what gives baked bread its airy texture.Since yeast also produces alcohol as it feeds, it is an important ingredient in beer production.

WHAT TO DO

1. Measure the length and circumference of your balloon. Record the results.

2. Place the small end of the funnel into the opening of the balloon.

3. Pour 1 tablespoon of yeast and 1 teaspoon of sugar into the balloon using the funnel.

4. Slowly add the cup of very warm water.

5. Remove the funnel from the balloon and tie it closed.

6. Place the balloon in a warm place.

7. Measure the length and circumference of the balloon

every 15 minutes for an hour. Record the results.

KEY QUESTIONS

What special characteristic of yeast made the balloon inate?

Why was the sugar added?

Why did we need to put the balloon in a warm place?

Would you get the same results if the balloon was untied?

EXTENSIONS

Design an experiment to explore one of the followingquestions. Examples:

Which sugar/food helps the yeast produce the most gas?

Try different foods for the yeast to ferment, e.g. brown

sugar, syrup, honey, candy, salt.

At what temperature is the yeast most active? At what

temperatures is it unable to blow up the balloon?

Try varying the water temperature, using a thermometer

to measure the temperature of the water.

OBJECTIVES:

Determine variables used in an

experiment of their own design.

Create a hypothesis.

Describe one of the byproducts

of respiration.

Describe the properties of gases


BY GRADE:

1. Life Science

2. Physical Science

5. Life Science

5. Processes of Science

6. Life Science



MATERIALS:

Per pair of students:

1 tbsp (15 ml) dried yeast

(not fast-acting)

1 teaspoon (5 ml) sugar

1 cup (250 ml) very warm water

(105115F or 4146C)

funnel

balloon

measuring tape (exible kind)

spot near a heat source

(like a radiator or a sunny window)

EXPLORATION


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6/19

ACTIVITY 2:FIREFIGHTING CO2BALLOONS 1015 MINUTES

In this demonstration, students witness carbon dioxide being produced by a reaction between

two common household chemicals. They then use one of the physical properties of carbon

dioxide to extinguish a ame with what looks like magic.

Mixing vinegar (acid) and baking soda (base) creates a chemical reaction. When the two

combine they create carbon dioxide (CO2) gas. When baking soda is mixed with an acid

such as chocolate, yogurt, buttermilk or honey in mufns or a cake, the same type of

chemical reaction occurs. The released bubbles of CO2uff up the batter.

When the reaction takes place inside a closed balloon, the CO2pushes against the walls

of the balloon, causing it to expand. This serves as evidence that a gas is being produced

inside the balloon.

CO2

is heavier than air. When released from the balloon into a glass, it will collect at the

bottom. If this CO2is poured over the ame, it pushes the lighter air out of the way.

The ame needs the oxygen in the air to burn, so the carbon dioxide puts out the ame.

One type of re extinguisher uses carbon dioxide. It pushes oxygen out of the way, putting

out the re. This type of extinguisher leaves no mess behind, as opposed to chemical-,

water-, and foam-based extinguishers. Carbon dioxide extinguishers are used in theatres,

computer rooms, or other sensitive telecommunication areas.

If you wait too long to pour the carbon dioxide gas on the ame, the demonstration will not

work. One of the properties of gas is that it will diffuse evenly in the space that surrounds it.

This is why we do not live in a layer of CO2where the life expectancy would be 2.5 minutes!

WHAT TO DO

Part 1: Producing the carbon dioxide gas1. Place the plastic pop bottle/conical ask on the table.

2. Carefully pour the vinegar into the bottle.

3. Open up the mouth of the balloon (put the rst

two ngers or thumbs on each hand inside the

mouth of the balloon and stretch).

4. Ask a student to spoon the baking soda into the balloon.

5. Without spilling any of the baking soda, stretch

the mouth of the balloon over the neck of the bottle.

6. Turn the balloon upright so that the baking soda insidethe balloon pours into the bottle with the vinegar.

7. Swirl the bottle a little to mix the contents.

8. The mixture will zz and produce bubbles, lling the

balloon with carbon dioxide.

9. Do not dismantle the balloon and bottle.

OBJECTIVES:


Describe the effects of

an acid/base reaction

Compare the relative weights

of two gases

Describe the properties of gases

Describe the elements required

for a ame to burn


BY GRADE:

2. Physical Science


7. Physical Science


MATERIALS:

Part 1: Producing the CO2

1 teaspoon (5 ml) baking soda

cup (60 ml) vinegar

1 litre plastic pop bottle

or conical (Erlenmeyer) ask

1 balloon

Part 2: Extinguishing the CO2

CO2-lled balloon-bottle

contraption from Part 1

1 balloon

2 tall glasses

candle with candle holder

matches or lighter

DEMO


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Part 2: Extinguishing a ame with carbon dioxide gas

1. Light the candle.

2. Ask a student to blow up the second balloon, trapping the air by pinching the neck of the

balloon. Do not tie the balloon

3. Ask the student to empty the air-lled balloon contents into one of the glasses by opening

the balloon above it.

4. Ask the student to pour the air from the glass onto the candle. Nothing should happen.

5. Remove the CO2-lled balloon from its bottle, keeping the CO

2trapped by pinching the neck

of the balloon. Do not tie the balloon.

6. Carefully empty the contents of the CO2balloon into the second glass.

Pour the CO2onto the candle. The ame should go out!

To see a video demo: http://www.columbiascientic.com/kids-science-experiments/

kids-science-experiment-to-show-co2-is-heavier-than-air

KEY QUESTIONS

The balloon expands when CO2is added to it. Why doesnt the bottle expand like the balloon?

If CO2is heavier than air, predict what will happen if the CO

2trapped in the balloon is poured

onto the air in the glass.

Some re extinguishers use CO2to put out res. Why are these more effective than just

blowing air onto on a re?

EXTENSIONS

What could you use instead of vinegar to create a similar reaction? Test your hypothesis.

Is a balloon blown up by a person heavier or lighter than a balloon blown up by a balloon

pump? Test it, and compare both these balloons to a balloon blown up using the baking soda

vinegar reaction.


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NOTES


8/19

ACTIVITY 3:WINDBAG 1015 MINUTES

INTRODUCTION

Students discover the fastest way to inate a windbag using Bernoullis Principle. Bernoullis

Principle states that as the speed of air increases, its pressure decreases. When you blow a big

breath near (but not on) the opening of the bag, you increase the speed of the air molecules

and create an area of low air pressure. The surrounding high-pressure air rushes in to ll in the

low-pressure area you created (winds will blow from high to low). As a result, a large quantity

of air from the atmosphere is drawn into the bag at the same time as you blow into the bag.

If you blow with your mouth right on the opening, the only air going into the bag is the air from

your lungs. You need a lot more breaths to ll the bag this way.

WHAT TO DO

1. If using a windbag, tie a knot at one end. Ask the class how many breaths it will take to blowup the bag.

2. Choose a volunteer to blow up the bag (depending on the size of the person, it may take

anywhere from 10 to 50 breaths of air). Get the class to count the breaths out loud.

3. Let all of the air out of the bag and tell the class that you can blow up the bag in one breath.

4. Ask the student volunteer to gently hold the closed end of the bag.

5. Hold the open end of the bag approximately 25 cm (10 inches) away from your mouth.

6. Using only one breath, blow as hard as you can into the bag. Remember to stay about 25 cm

away from the bag when you blow.

7. Quickly seal the bag with your hand so that none of the air escapes.

8. Without explicitly pointing out how you did it differently from your volunteer, ask another

student to repeat what you just did.

KEY QUESTIONS

What was the difference between how the two bags were blown up?

Using Bernoullis Principle, where does the extra air that goes into the balloon come from

when your teacher blew into the bag?

How does putting your mouth further from the opening make a difference?

EXTENSIONS

How would reghters use this principle to force smoke out of a building using high-poweredfans? Fireghters use Bernoullis Principle to quickly and efciently force smoke out of a

building. Instead of placing the fans up against the doorway or window, a small space is left

between the opening and the fan in order to force a greater amount of air into the building.

Fireghters call this Positive Air Flow.

Other activities illustrating Bernoullis Principle can be found in Science Worlds Air Teacher

Resources Module.

Check out the Dyson Air Multiplier fan. Can Bernoullis Principle help explain why it works?

http://www.dyson.com/technology/airmultiplier.asp

OBJECTIVES:


Describe the characteristics of air

Explain how air pressure works

Discuss how air pressure affects

our daily lives


BY GRADE:

2. Physical Science

2. Earth and Space Science4. Earth and Space Science

6. Earth and Space Science

MATERIALS:

an ofcial wind bag (long plastic

bag in the shape of a tube,

8 ft x 10.5 that can be purchased

on the Steve Spangler Science website

for approximately 5$ - the demo is

impressive due to the size of the bag)

OR

an extra-large garbage bag with theopen end scrunched to make a smaller

opening

OR

a Diaper Genie rell bag (available at

most department stores)

DEMO


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9/19

ACTIVITY 4:BALLOON SHISH KEBAB 10 MINUTES

INTRODUCTION

Students discover a cool characteristic of polymers that contributes to a balloons elasticity.

When a sharp skewer stick is placed through the tie and the nubbin (end opposite of the tie),

the balloon does not pop. The balloons rubber consists of many long chains of molecules

called polymers, linked together like noodles stuck to each other in a plate of cooked

spaghetti. These links can be stretched and compressed, giving the balloon its elasticity.

If they are pulled too much, however, the balloon will break.

The rubber at the nubbin and at the tie is looser and less fragile than around the circumference

of the balloon, where the polymers are already stretched to their limit. When the skewer slides

into the loose rubber, the polymers will stretch around the skewer allowing the balloon to stay

inated. A needle through the side of a balloon will cause the rubber to tear and pop easily

since the polymers are already stretched.

WHAT TO DO

Preparation:

1. Sharpen the metal skewer stick with a le. If using a wooden skewer, remove any splinters.

2. Blow up both balloons, to about 75% full (a volunteer student could do this to show that a trick

is not being played on them).

Instructions:

1. Slowly twist the skewer through the side of the rst balloon. The balloon should burst.

2. Slowly twist the skewer through the nubbin (top) and the dark part next to the tie (bottom)

of the second balloon. The balloon should not burst.

Tips:

Gently twist the skewer as it goes in.

Coat the skewer in lubricant (e.g. wiping with an oil-dipped cloth or Vaseline) before inserting

into the balloon.

Use a round balloon so that skewer will t through it.

It may help to blow the balloon up fully and then release some air, leaving it full.

OBJECTIVES:


Explain how a balloons chemical

structure gives it its elasticity


BY GRADE:

2. Physical Science

3. Physical Science

7. Physical Science

MATERIALS:

2 round balloons

sharp skewer

(metal or wooden with no splinters)

lubricant such as oil or Vaseline

(optional)

DEMO


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KEY QUESTIONS

What is the difference in properties between the nubbin and the side of the balloon?

Describe the behaviour of the molecules when the skewer pierced the nubbin and whenit pierced the side of the balloon.

Why are the nubbin and tie ends darker in colour than the rest of the balloon?

EXTENSIONS

What will happen if we pierce a skewer through the nubbin of the balloon and then blow it up.

There is a way to stick a sharp pin or skewer through the side of a balloon without popping it.

Put a small piece of Scotch tape on the side of the balloon and press it down well. Now take

the pin and press it through the tape and into the balloon. The balloon will not burst. The tape

sticks to the rubber in the balloon and will not allow the rubber to stretch to the breaking point

when the pin pierces the balloon. In other words, the tape reinforces the cross links of the

rubber polymers, and the balloon stays together.


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NOTES


11/19

ACTIVITY 5:BALL IN THE BALLOON GAG 10 MINUTES

INTRODUCTION

In this demo, students must brainstorm an explanation for the mysterious behaviour of

a balloon that stays inated without being tied. The answer lies in the force that is exerted

by air inside the balloon.

When a rubber bouncy ball is placed inside of a balloon, the ball falls toward the opening,

acting as a stopper by preventing the air from escaping even if the balloon is not tied.

Since the air pressure inside the balloon is greater than its surroundings, it pushes against

the inner walls of the balloon trying to equalize the low-pressure air around it. The ball

is basically in the way and is pushed against the opening by the air inside the balloon.

In other words, the air molecules in the balloon exert a force on the ball, keeping it in place.

WHAT TO DO

Preparation:

1. Squeeze a rubber bouncy ball into the dark coloured balloon. Do not let the students see you

do this.

Instructions:

1. Blow up the balloon. Do not tie it off.

2. Hold the balloon upright so the ball descends and covers the opening. The balloon should

stay inated. Ask the students to speculate about how this is happening (think, pair, share).

They may guess that something is acting like a stopper.

3. Turn the balloon upside down, with the neck up. The air pressure in the balloon will hold the

ball in place, keeping the balloon from deating. Ask the class to explain what is happening.

4. Tap the balloon so the ball falls down and the air comes out. Show the students the outline

of the ball in the balloon.

KEY QUESTIONS

What could be keeping the balloon from deating?

Now that youve gured out that something is blocking the air from coming out, what should

I do to let the air come out?

Does turning the balloon upside down support your theory?

What is keeping the ball in the opening?

In which direction is the air (in the balloon) pushing?

How do I let the air out?

EXTENSIONS

When you let go of an inated balloon WITHOUT a ball inside, the elasticity of the balloon

forces the air out and pushes the balloon forward. Use this principle to make balloon-powered

rockets and boats.

Balloon-powered boats (http://www.scienceworld.ca/pdf/TTH/Balloon-powerd%20Boat.pdf).

OBJECTIVES:


Describe the characteristics of air.

Explain how air pressure works.


our daily lives.


BY GRADE:

2. Physical Science

2. Processes of Science2. Earth and Space Science




MATERIALS:

dark coloured balloon (opaque)

bouncy rubber ball

DEMO


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12/19

ACTIVITY 6:BALLOON AND CUP ATTRACTION 10 MINUTES

INTRODUCTION

In this demonstration, students discover that variances in air pressure can be exploited to

create suction.

When the balloon is small, it is curved and takes up a lot of room in the cup. As the balloon

inates, less of the balloon is in the cup, increasing the volume available to the air molecules

trapped inside the cup. This reduces the air pressure inside the cup since the air molecules

now have more space to move around. Meanwhile, the higher pressure air outside the cup

pushes the cup into the balloon. In other words, the suction is really the pressure of the air

outside the cup pushing the cup into the balloon and causing it to stick there.

A great visual is to introduce the idea of a push of war (instead of a tug of war). The (higher)

pressure of the air outside the cup pushes the cup into the balloon harder than the (lower)

pressure inside the cup pushes out.

WHAT TO DO

1. Blow up the balloon so that it is the size of a

grapefruit or softball.

2. Place the cup upside down on the upper side

of the balloon.

3. Continue blowing up the balloon.

4. Pinch the neck of the balloon and ask the students

what would happen if you turned the balloon over.

5. Rotate the balloon, without letting any air escape,

so that the cup is on the bottom.

6. The cup will stay attached to the balloon.

Tip:

Squeeze the sides of the cup as you attach it (forces some air out to create better suction)

KEY QUESTIONS

What is in the cup?

Can any more air get into the cup?

Whats happening to the volume of the space inside the cup?

Explain with arrows how the difference in pressure causes the cup to stick to the balloon.

Hint: air always ows from a high (pressure) area to low (pressure) area.

EXTENSIONS

How big does the balloon have to be to make the cup stick?

How many cups can stick on one balloon?

Try this experiment with a coffee mug or a cup with water in it. Try to dislodge the cup with

your nger.

OBJECTIVES:


Describe the characteristics of air.

Explain how air pressure works.


our daily lives.

Describe how air pressure

explains suction.


BY GRADE:

2. Physical Science





MATERIALS:

a balloon

a plastic cup

DEMO


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13/19

ACTIVITY 7:FIREPROOF BALLOON 10 MINUTES

INTRODUCTION

Students defy logic by putting ame to a balloon without popping it, thanks to the ability

of water to conduct heat.

Water has a high heat capacity. In other words, it takes a lot of heat and energy to change the

temperature of water by 1C. The high heat capacity of water is due to the fact that it takes a lot

of energy to separate water molecules (the bonds are very strong). Water has a heat capacity

about four times that of air. This means that it takes about four times as much heat to raise

the temperature of a balloon full of water than it would a similar sized balloon lled with air.

As the water-lled balloon is put on the ame, the heat of the ame is easily absorbed through

the balloon and into the water. The water directly above the hot spot rises, cools, and sinks

again, carrying away the heat from the hot spot (this cycle is called a convection current).

In other words, the thin rubber surface that is being heated is cooled by the comparativelylarge volume of water above it. This cooling process continues until either all of the water

in the balloon becomes too hot, or until a far more concentrated source of heat, such as a

blowtorch, is applied to one small area on the balloon.

When an air-lled balloon is placed in a ame, it bursts. Air is a relatively poor conductor of

heat away from the thin layer of rubber. As a result, the rubber overheats and the molecular

bonds holding the rubber polymers together are broken.

WHAT TO DO

1. Blow up a balloon and tie it off.

2. Light a candle and place it in the middle of the table so the students can see.

3. Put on your safety glasses.

4. Hold the balloon 3050 cm over the top of the ame and slowly move the balloon closer

and closer to the ame until it pops. Note: The ame does not need to touch the balloon

before the heat melts the latex and it bursts.

5. Add about 60 ml of water to the second balloon and then blow it up to the same size as the

rst balloon.

6. As before, slowly lower the balloon over the candle ame. The balloon will not pop. You can

let the ame touch the balloon and it will still not pop. It will leave a sooty mark on the bottom

of the balloon.

KEY QUESTIONS

Predict what will happen when I bring the balloon with air to the ame.

For the balloon with water inside, what could happen (possible answers: the balloon will burst;

the balloon will take more time to burst; the balloon will take less time to burst; the balloon

will never burst.)

Why does the balloon with water in it not burst?

What did you notice about where the ame touched the balloon?

OBJECTIVES:


Describe the relationship between

waters heat capacity and thermal

heating or cooling


BY GRADE:

2. Physical Science



7. Physical Science

MATERIALS:

a pair of safety glasses

2 round balloons

matches or lighter

a candle with candleholder

60 ml of water

DEMO


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14/19

EXTENSIONS

How does this relate to oceans and the temperature inland vs. by a coast? How would changing

the amount of liquid in the balloon affect the results? Boil water in a paper cup over a Bunsen burner.

Make predictions regarding the heat capacity of water versus other liquids (e.g. honey or

shampoo). Which will heat up faster? Do not test any ammable liquids (e.g. alcohols or lighter

uid) or liquids that produce noxious fumes.


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NOTES


15/19

ACTIVITY 8:BALLOON-BOARDING 15 MINUTES

INTRODUCTION

This demo uses the concept of weight distribution over a large area to carry students

on balloons.

When a person puts his whole weight on one balloon, all of the pressure from that person is

concentrated on one small area of the balloon, which results in the balloon bursting. When the

persons weight is distributed over several balloons, the balloons do not burst because the

pressure is spread over a large area. As a result, each balloon only supports a small fraction

of the weight.

This trick only works if the balloons are not fully inated. If this demonstration is done with

fully inated balloons, the rubber is already stretched out and is less elastic. Balloons that

are only partially blown up still have the ability to stretch.

This demonstration is similar to asking a volunteer to lie on a bed of nails, a common

exhibit found in science centres. If the volunteer were to sit on one nail, it would be extremely

painful. But if the weight is distributed over hundreds of nails, there is very little pressure on

each individual nail, rendering the experience quite comfortable. The difculty is when the

person is in the process of lying down or getting up, since her weight is distributed on fewer

nails, resulting in more pressure being exerted on each nail. Some science centres install

handrails on either side for the volunteer to lie down and get up safely. Others have a

mechanized system, whereby the volunteer lies down on a table with holes and the nails

all rise at the same time, lifting the volunteer.

WHAT TO DO

Preparation:

1. Blow up the balloons, but not fully (75%). It can help to blow the balloons up completelyand then let air out until theyre at 75% full.

Instructions:

1. Spread the towel out on the oor.

2. Ask for two volunteers. Place all of the balloons on the towel. Help the volunteers place

the board on top of the balloons.

3. Position one volunteer at either side to stabilize the board.

4. Invite another student volunteer to step onto the board. Remind him not to jump or bounce.

5. Continue adding students until the balloons start bursting.

OBJECTIVES:


Describe the concept of weight

and force distribution


BY GRADE:

K. Physical Science

3. Physical Science

5. Physical Science

MATERIALS:

a wooden board or door, or upside

down table

a large towel

1014 inated balloons (about 75%

inated, not fully blown up)

DEMO


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Balloons

NOTES


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KEY QUESTIONS

How many people can stand on the board without the balloons bursting?

Why did we use partially inated balloons? What is happening to the balloons under the board?

Why did the teacher say not to jump onto the board?

If one student stands on one balloon, it will burst. How does putting a board over several

balloons increase the balloons ability to carry weight?

EXTENSIONS

Try reducing the number and/or placement of the balloons.

Try fully inated balloons.

What would happen if the board wasnt there? Could a student lie over the balloons without

bursting them?

The bed of nails circus trick also relies on the principle of spreading the weight of the person

lying on the nails. This can be shown with an experiment using a balloon and a small scale

model of a bed of nails: http://www.stevespanglerscience.com/experiment/bed-of-nails1.

CONCENTRATED PRESSURE DIFFUSED PRESSURE


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Balloons

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ACTIVITY 9:BALLOON HOVERCRAFT 30 MINUTES

INTRODUCTION

Students explore Newtons third law of motion (for every action there is an equal and

opposite reaction) by building a hovercraft.

The small hole in the centre of the CD forces air escaping from the balloon downwards.

This creates an opposite force upwards which lifts the hovercraft off the ground, explained

by Newtons third law of motion. The CD spreads out this force evenly along the bottom of

the hovercraft.

Having a thin layer of air helps also helps the hovercraft move by reducing the amount of

friction between the CD and the ground.

WHAT TO DO

Preparation:

1. If using glue guns, set up four hot glue gun stations around the classroom. This ensures that

the mess will be contained!

Instructions:

1. Hand out a CD, a sport drink cap, and a balloon to each student.

2. Glue the bottom of the sport drink cap to the shiny side of the CD, making sure that the hole

in the cap and CD are aligned. Hold for a few seconds or until the glue is dry.

3. Put the balloon over the top of the sport drink cap.

4. Blow up the balloon through the CD.

5. Pinch or twist the neck of the balloon to prevent the air escaping.

6. Place the hovercraft on the ground and let go of the balloon.

TOPICS:

Newtons third law of motion

Properties of air

Forces

OBJECTIVES:


Describe Newtons third law

of motion and its applications

Describe the effect of friction

on movement


BY GRADE:

1. Physical Science (force and motion,

force and friction)

2. Physical Science (properties of

matter, gas)

5. Physical Science (forces and

simple machines)

MATERIALS:

4 hot glue guns and glue sticks,or duct tape

For each student:

CD

sport drink cap (with pop-out nozzle)

balloon

MAKE + TAKE


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Step 1

Step 2

Step 3


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KEY QUESTIONS

When the balloon is released, where will the air go up, down, or to the sides?

What would be the opposite and equal reaction, according to Newtons third law?

EXTENSIONS

Drag the hovercraft along the ground with the balloon deated. Blow up the balloon and

do the same thing. Why is it easier to move when the balloon is inated? Less friction.

How can you alter your hovercraft to make it go faster? Slower? (Bigger/smaller balloon).

Design an experiment to test your theory.


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Balloons

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ACTIVITY 10:BALLOON POPPING RELAY 20 MINUTES

INTRODUCTION

In this relay race, students discover the strength of chemical bonds by trying to out-pop the

other teams.

A balloons rubber consists of many long chains of molecules called polymers. The chains are

linked together like noodles stuck to each other in a plate of cooked spaghetti. These links

can be stretched and compressed, giving the balloon its elasticity. If they are pulled too much,

however, the balloon will break.

WHAT TO DO

Preparation:

1. Blow up enough balloons for each student playing the game.

2. Divide the balloons equally into 4 bags or bins.

3. This is a relay race. Divide class into 4 groups and have the groups line up across the eld

from their balloon bags

4. At the start signal, the rst students of each line must race to their bag and pull out one

balloon.

5. The students must pop their balloon as quickly as possible by sitting on it, stepping on it,

or by other means.

6. When they have popped their balloon they must race back and tag the next person on

their team.

7. The rst team to have all their balloons popped wins!

8. Be sure to clean up and dispose of the broken balloons carefully. Balloon rubber is harmful

to wildlife.

KEY QUESTIONS

What was the most effective way of popping your balloon?

Why does jumping on the balloon have a more immediate effect than stepping on a balloon?

What chemical property of balloons make them expand when you step on them?

OBJECTIVES:


Explain how a balloons chemical

structure gives it its elasticity


BY GRADE:

K. Physical Science

1. Physical Science

7. Physical Science

MATERIALS:

balloons (one per student and

a few extra)

a balloon pump

4 large bins or bags

eld or gym

GAME

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Balloons

NOTES

balloons full

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