A Book of Experiments

Transcription

~A Book of Experiments~
For use in teaching elementary
School science
Organized to support the Massachusetts Science and
Technology/Engineering Curriculum Frameworks
Compiled by Grade 11 Scientific and Technical Writing Students at
the Massachusetts Academy of Math and Science at WPI
Fall 2009
Table of Contents
Massachusetts Science and Technology/Engineering Curriculum
Framework: Physical Sciences Learning Standards--Grades 3-5
Differentiation between properties of objects (e.g. size, shape, and weight) and
properties of materials (e.g. color, texture, hardness):
Density
Cauldron Bubbles
Making a Lava Lamp
Making a Flinker
Polishing Pennies
Floating Eggs
Compare and contrast solids, liquids, and gases based on the basic properties
of these states of matter:
Balloon Bottle Blow-Up
Can you blow up a balloon with a lemon?
The Rising Hand
The Great Pepper Dispersion
Cloud Dough
Splitting Water
Pouring Water Sideways
Surface Tension
Lifting an Ice Cube
That Which Doth Not Mix
Sink a Dime
Air Takes Up Space
Gravity Free Water
Under Pressure?
Capillary Action
Air Currents: Heat Rises
Air Pressure
Candles and Air Pressure
Humpty Dumpty Had a Great Fall
Oobleck
Cornstarch, Water, and Oobleck
Carbon Dioxide Fire Extinguisher
Shrinking Water Bottle
Identify the basic forms of energy (light, sound, heat, electrical, and magnetic).
Recognize that energy is the ability to cause motion or create change:
Friction
Sliding vs. Rolling Friction
Give examples of how energy can be transferred from one form to another:
Burning Money
Rubber Band Car
Identify and classify objects and materials that conduct electricity and objects
and materials that are insulators of electricity:
Laws of “Attraction”
Electrified Dice
Bending Water
Fun with Static Electricity
Charge for Cheerios
Recognize that magnets have poles that repel and attract each other:
Magical Magnetism
Make an Electromagnet
Floating Paper Clip
Recognize that light travels in a straight line until it strikes an object or travels
from one medium to another, and that light can be reflected, refracted, and
absorbed:
Sky in a Jar
Making a Rainbow
Somewhere over the Rainbow
Miscellaneous Science and Math Activities:
The Water Drop Microscope
Pendulums
Density
Materials

1/8 cup water

1/8 cup vegetable oil

1/8 cup corn syrup

1 clear plastic cup
Procedure

Pour 1/8 cup of corn syrup into the clear plastic cup.

Pour 1/8 cup of water into the same cup.

Pour 1/8 cup of vegetable oil into the cup.

What do you see? Record observations.

Stir the mixture until it appears to be completely mixed.

What happens? Record observations.
The Scientific Explanation
The vegetable oil, water and corn syrup do not mix because the liquids have
different densities. Liquids with different densities do not combine because
one liquid is heavier than another; in this case all three liquids have different
densities. When these liquids are stirred or shaken they separate over a period
of time, with corn syrup on the bottom, water above the corn syrup, and
vegetable oil on the top. The bottom liquid is the heaviest, and the liquid
directly above it is the second heaviest and so on. This means corn syrup is the
heaviest liquid, water is the second heaviest liquid, and vegetable oil is the
third heaviest liquid.
Cauldron Bubbles
Materials:
 ¾ cup water
 ¼ cup olive oil or vegetable oil
 Salt (NaCl)
 1 tall, clear glass or plastic bowl
 Teaspoon
Procedure
 Fill the glass halfway with water.
 Add about an inch of oil in the glass.
 Let all of the oil settle out on top of the water.
 Add some salt in the glass using a teaspoon. Notice what
happens to the salt and the oil.
 Wait until some of the salt on the bottom dissolves and
see what happens.
 See if you can make cauldron bubbles with other
substances like sugar or sand.
Density is how tightly packed matter is in an object. Different
substances have different densities. When water and oil are put in
the same glass, the oil seems to float on top of the water. This is
because oil is less dense that water, so it settles out on top. When a
substance is denser than oil and water, it will settle out on the
bottom of the glass. When you add the salt in the glass, a bubble of
oil is formed around it. Because the salt and the oil put together
are denser than the water, the bubble sinks to the bottom. But,
when the salt dissolves, the bubble of oil floats back up to the top
because it is less dense than the oil again.
Lava Lamp
Materials
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1 Table spoon salt
1 cup water
Tall drinking glass
Procedure
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Take a tall drinking glass and fill it about 2/3 with water.
Pour vegetable oil into the cup until the oil is 1 cm thick.
Fill a table spoon with salt.
Sprinkle the salt into the cup.
What do you see?
Scientific explanation
Density is the measurement of mass and volume. When a
water (higher density) is mixed with oil (lower density), the oil
floats on top. Salt has a density that is higher than either oil or
water, so when salt is added, sinks to the bottom of the glass,
carrying some oil with it. As the salt begins to dissolve in the
water, the oil is released and floats back up to the top of the
glass.
The oil and water didn‟t mix because they have different
polarities. Water has a charge (like a magnet) that attracts other
substances. Oil on the other hand does not have a charge. That
is why when going through water oil looks like little bubbles but
doesn‟t mix with the water.
Making a Flinker
Materials
 styrofoam peanuts
 paperclips of various sizes
 a container of water
Procedure
Work in pairs
Obtain a few Styrofoam peanuts and paper clips
Fill a container with water
Now drop one paper clip and one Styrofoam peanut into the
container
 Which object floats and which object sinks?
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Floats: ________________________ Sinks: ________________________
 Using your Styrofoam peanuts and paperclips brainstorm and
try to create an object that flinks!
Flinker:
A flinker is an object that does not float or sink; it is
suspended midway in the body of water.
(Hint*) you can combine the paper clips with a foam peanut by
unraveling the paper clips and puncturing the peanut.
(Hint*) you may need to squeeze your Styrofoam peanut
occasionally because when it gets extremely soaked through it
works much worse.
Through this experiment the scientific principle of density is
illustrated. The density of water is equal to one, and if an object
has a greater density then water it will sink, and if density is less
than that of water it will float. A flinker will have a density of one
because it is suspended midway in the body of water. This
experiment begins to introduce children to the principle of density.
As children get older, during eighth or ninth grade they will go
deeper into the principle of density and learn that density = mass /
volume.
Polishing Pennies
Materials:

Dishwashing detergent

Distilled white vinegar

Lemon juice

Cola

Distilled water

5 rusted copper pennies

5 small plastic cups or containers

1 disposable plastic spoon

A measuring spoon that measures teaspoons

A measuring cup (measures cups)

A large glass
Procedure

Pour 1 cup of water into the measuring cup and pour it into the
tall glass.

Measure ¼ teaspoon of detergent with the measuring spoon and
pour the liquid into the tall glass, too.

Stir the water and detergent in the glass with the plastic spoon.

Place a penny in each of five small plastic cups.

Pour enough lemon juice, vinegar, detergent solution, water, and
cola to completely submerge a penny into separate cups. Each cup
should have a penny and a different liquid in it.

Let the pennies sit in the liquids for five minutes. What changes in
the cups do you notice?

After the five minutes, remove each penny from the cups with the
plastic spoon, placing each coin on the work surface. Clean the
spoon after each removal.

Dry the pennies with a paper towel and note any removable
substances.

Pour the vinegar, lemon juice, water, cola, and detergent down a
sink drain.
Scientific Explanation
The pennies are made from copper, which reacts with the air to form a
thin oxide coating. This is because copper atoms are positive, and the oxygen
atoms in the air possess negative properties. Like magnets, the positive and
negative charges attract each other to form new compounds. The acids in the
cola, lemon juice, and vinegar remove the oxides, but the detergent and water
do not react with the penny surfaces. This explains the occurrence of the
substance that was removed from the penny in the vinegar with the paper
towel.
Floating Eggs
Materials
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

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1 raw egg
1 beaker
1 teaspoon
Bag of salt
Balance (triple beam or electronic)
Procedure
 Take the mass of the beaker.
 Fill the beaker about halfway and record the amount of water
inside (the volume).
 Take the mass of the beaker with the water in it.
 Calculate the mass of the water by subtracting the mass of
the beaker from the mass of the beaker with water.
 Take the mass of the egg.
 Tilt the beaker and gently slide the egg in. Don‟t let the water
splash out!
 Record how much water the egg displaced. This is the volume
of the egg.
 Add one teaspoon of salt at a time to the water. Record
results after adding every spoon of salt. How many teaspoons
of salt does it take before the egg starts floating?
 Take the egg out of the water using the spoon. (Try not to
remove any water)
 Take the mass of the beaker and salt water.
 Calculate the mass of the salt water by subtracting the mass
of the beaker from the mass of the beaker with salt water.
 Calculate the density of the water, egg, and salt water.
Density is calculated with the formula mass/volume. Compare the
densities.
The egg floats on salt water but not on cold water because of
density. Density is the measure of the compactness of a substance
― how closely the atoms of the substance are packed together.
Density is calculated with the formula mass/volume. This experiment
also demonstrates the concept of buoyancy. Buoyancy is the
concept that something with a smaller density will float on a liquid
with a higher density. This experiment demonstrates that salt water
is denser than fresh water because the egg will float in the salt
water but not in the fresh water. This experiment also shows that
items with a smaller density float on items with a higher density.
Balloon Bottle Blow-up
Materials

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
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1 Balloon
About 40 mL of water
1 20 oz. soda bottle
Drinking straw
Vinegar
About 1 teaspoon of baking soda
Procedure
 Stretch out the balloon before beginning so that it will be
easier to blow up the balloon.
 Pour the water and the baking soda into the soda bottle and
stir the mixture with the drinking straw.
 Pour in the vinegar, and quickly stretch the balloon over the
mouth of the bottle.
 Start shaking the bottle right after the balloon is stretched
over the bottle.
 Make sure to time how long it takes for the balloon to blow
up.
 Repeat the entire process again, but do not shake the bottle
and time how long it takes for the balloon to blow up now.
The balloon will inflate. Adding vinegar to the baking soda and
water creates a chemical reaction. The baking soda is a base, and
the vinegar is and acid. When the acid and base come into contact,
they make carbon dioxide. It rises up through the bottle and into
the balloon, filling it with the carbon dioxide. It fills up faster when
you shake the bottle because the vinegar and baking soda are mixed
together more to make more carbon dioxide. You can also use lemon
juice instead of vinegar as an acid.
Can You Blow Up A Balloon
With A Lemon?
Materials
 1 lemon cut into two halves
 A measuring cup
 A balloon
 An empty soda or water bottle
 1 oz. of water (30 mL)
 A teaspoon (5 mL)
 Baking soda
Procedure
 Cut the lemon in half and squeeze as much lemon juice
possible from both halves into the beaker or small
container.
 Hold a balloon at both ends and stretch it back and
forth a few times.
 Carefully pour 1 oz. (30 mL) of water into the empty soda
or water bottle. Make sure it is clean.
 Dissolve 1 teaspoon of baking soda (5 mL) in the bottle.
 Pour in the lemon juice as well and swirl the contents of
the bottle around a few times so that the solutions mix.
 Fit the opening of the stretched balloon over the mouth
of the bottle. What happens?
Baking soda is sodium bicarbonate, a base, and lemon juice is an
acid, which tastes sour. When carbonates and acids are mixed
together, carbon dioxide is produced. This gas is what floats up
into the balloon and makes it expand. This experiment can be
extended by changing the experiment slightly. More baking soda or
more lemon juice can be used to see which produces more carbon
dioxide (which causes the balloon to be bigger). This experiment can
also be tried without using any water and seeing if there are any
effects on the reaction.
The Rising Hand
Materials




Three teaspoons of white vinegar
One medical latex glove
Two teaspoons of baking soda
A glass jar with a wide mouth
Procedure
 Fill the jar with three tablespoons of white vinegar.
 Take out one glove from the box and pour two tea
spoons of baking soda inside.
 Wrap the base of the glove over the mouth of the jar,
making sure that no baking soda falls in just yet.
 When you are ready, take the attached glove and put it
inside the jar. What happens?
When vinegar and baking soda are mixed in a container, they react
violently. The acetic acid in vinegar and the sodium bicarbonate in
baking soda combine and form carbonic acid. However, carbonic
acid is very unstable and can't hold itself together. Thus the acid
falls apart into two compounds: carbon dioxide (the gas you breathe
out) and water. The carbon dioxide produced is heavier than the air
inside the jar so it pushes the air out of the way. Since air is a gas
and is being forced out by carbon dioxide, it advances upward. The
air then pushes up on the glove and viola, the glove rises! After all
gasses break free, the resulting liquid in the jar is a mixture between
water and leftover sodium acetate. The overall reaction is as
follows:
NaHCO3 (aq) + CH3COOH (aq) → CO2 (g) + H2O (l) + CH3COONa (aq)
The Great Pepper Dispersion
Materials:
 1 shallow bowl
 About 3 cups of room temperature water
 Pepper
 1 teaspoon of hand soap
Procedure:
 Pour the water into the shallow bowl so that there is a
liquid layer at least 1 inch deep.
 Sprinkle pepper over the surface of the water so that is
covers the surface evenly.
 Pour the hand soap into the center of the bowl.
 Observe the movement of the pepper to the outer rim of
the bowl.
The Scientific Explanation:
Water has an adhesive quality similar to glue that causes it to
stick to other water molecules and the pepper. The sticky water
molecules on the surface of the bowl form a film on the liquid
surface called water tension. Soap breaks this tension. The
water sticks to the soap rather than the pepper. The water
molecules on the edge of the bowl that have not touched the
soap are still pulling on the pepper. Without an even amount of
molecules pulling on the pepper in each direction, it travels to
the side of the bowl that is pulling the strongest. That is why all
the pepper moves away from the soap. The soap isn‟t pushing the
pepper away. The water molecules on the outer rim of the bowl
are pulling on the pepper harder than the water molecules in the
middle.
Cloud Dough
Materials
 2 cups flour
 1 tablespoon powdered Tempera
 2/3 cup water
 A medium size mixing bowl
 A measuring cup
 A tablespoon
 Optional: Food Coloring
Procedure
 Pour the flour and vegetable oil into the bowl
 Mix the flour with the oil (and color if desired)
 Add directed amount of powdered tempera and mix well
 Slowly add water and simultaneously knead the mixture
well
 If necessary, add more water in small amounts
 Continue kneading the mixture until the dough is soft
and elastic
 Store dough in a refrigerator (in a covered container) if it
needs to be preserved
This experiment is used to demonstrate basic chemistry
principals. It displays how molecules in different compounds mix
together, and how they can form a new compound with an entirely
different consistency. When the vegetable oil is added to the flour
it gives the resulting mixture a more solid consistency. The powered
tempera is added as a reactant to maintain that consistency while
the water is being added. Powdered tempera is made from a mixture
of corn starch, dried and powdered egg yolks, and other chemicals
that are used to absorb liquid. So instead of turning this mixture
into a liquid-like mess, it creates an even more solid form for the
mixture. The end result of this experiment is the creation of a soft,
elastic dough, which is similar in the consistency to that of PlayDough.
Splitting Water
Materials
 A 9 volt battery
 Two regular number 2 pencils
(remove eraser and metal part
on the ends)
 Salt (1 teaspoon)
 Thin cardboard
 Electrical wire
 Small glass (about 1 cup size)
 Water (about ¾ cup)
 Tape
Procedure
 Remove eraser and metal parts from the ends of each
pencil. Sharpen each pencil at both ends.
 Cut the cardboard to fit over glass.
 Push the two pencils into the cardboard, about an inch
apart.
 Dissolve about a teaspoon of salt into the warm water by
stirring and let sit for 3 minutes.
 Using one piece of the electrical wire, connect one end on
the positive side of the battery and the other to the black
graphite (the "lead" of the pencil) at the top of the
sharpened pencil by wrapping it around. Do the same for
the negative side connecting it to the second pencil top. It
is helpful to use tape to help secure the wire to the
batteries, just be sure that the wire is still touching the
battery parts.
 Place the other two ends of the pencil into the salted
water.
 What do you observe happening at the tips of the pencils?
The electricity from the battery is passed through the wire into the
graphite of the pencil, which then transmits the electricity into the
salt water. The electricity then splits each water molecule into its
basic components: two atoms of hydrogen and one atom of oxygen.
There are twice as many bubbles on the pencil attached to the
negative side of the battery because the hydrogen atoms gather
there. Oxygen atoms accumulate on the pencil attached to the
positive side of the battery.
Pouring Water Sideways
Materials




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A clear plastic drinking cup
Cotton twine
A sink, bucket or other container
A counter top or other surface
Some scotch tape
Optional: A stack of books
Procedure

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
Cut, or have an adult cut a piece of string 3 feet long.
Tape one end of the string to the side of the cup near the top.
Fill the cup with cold water 2/3 of the way full.
Wet the string in the water until it is thoroughly wet.
Pass the string over the cup, resting it on the rim of opposite
side.
Find a place where you can do the experiment. You want some
sort of container to catch the water, and a place to rest the
cup that is about a foot above the ground. One good way to
do this is to use a sink with a counter around it- you can place
the cup on a stack of books, perhaps. This is not necessary,
but it helps to keep your hands steady during the experiment.
Place the cup (and the stack of books) about two feet away
from the sink or bucket where the water will be poured into.
Place the other end of the string in a sink. You may want to
place paper towels between the cup and the sink to catch any
accidental spills.
If you aren‟t using books, lift the cup about a foot off the
ground.
 Hold the string in the sink and pull it tight.
 Very carefully, begin to slowly pour the water out of the cup.
Keep the string tight! Make sure to hold the cup steady and
keep an even trickle of water. This is where the books are
helpful, because you can rest the bottom of the cup on the
books. If you did it right, no water will spill out and hit the
table!
This experiment works because of the “adhesive” and “cohesive”
properties of water. Water has a slight charge to it, and because of
this, it likes to stick to other things that have a charge. Water likes
to stick to other surfaces, which is called adhesion, and also sticks
to other water, which is cohesion. The water the string was wet
with sticks to the string. The water you pour down the string also
will stick to the string and the water in the string. Together, the
attraction between the water and the string and the water and the
water is enough to overcome the gravity that is pulling the water
down.
Surface Tension
Materials

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1 penny
1 eyedropper / pipette
1 foam cup
Concentrated dish soap
spoon
paper towels
tap water
Procedure




Wash the penny with soap & water, then dry.
Fill the cup with tap water.
Fill the eyedropper / pipette from the cup.
Hold the dropper above the penny and steadily add drops
one at a time, counting each drop as it falls.
 Stop adding water when it overflows the edges of the
penny and record the number of drops required.
 Add 1 drop of dish soap to the cup of water and dissolve
by stirring with the spoon.
 Dry off the penny, then repeat steps 3-5 using the new
soapy water solution.
 What do you observe? Does anything different happen
when the soapy water is used instead of regular water?
Water molecules consist of three atoms: 1 oxygen and 2 hydrogen.
However, because the oxygen atoms attract electrons more strongly
than hydrogen atoms do, this causes the hydrogen ends to have a
positive partial charge and the oxygen atom a negative partial
charge. A compound such as water that has these kinds of weak
partial charges is polarized. The molecules act like magnets, sticking
to each other. The weak attractions that cause this are called
hydrogen bonds. When water alone is added to the penny, the water
molecules are attracted to each other, causing surface tension,
which makes the water resist overflowing the edges of the penny.
However, when soap is added, it forms a layer on the surface of the
water that interferes with the intermolecular forces, causing the
water molecules to be attracted to each other less, decreasing
surface tension and thus, the amount of water needed to overflow
the edges.
Lifting an Ice Cube
Materials




Plastic Cup
Water
Table salt (NaCl)
A piece of string (about one ft. long)
Procedure
 Fill your cup about ¾ full with cold tap water.
 Stir until the salt dissolves.
 Place the middle of the string over the ice cube. Press the
string onto the ice cube so that the string stays on top of
the ice cube.
 Pour enough salt onto the point where the string touches
the ice cube so that the string is covered in a coat of salt
(about three pinches)
 Wait about 20 seconds.
 Lift the string. What happens?
Water turns into ice at a temperature of 32°F or 0°C; however,
salt causes water to have a lower freezing point. So, when salt is
sprinkled onto the ice cube, it melts some of the ice. The liquid
(water) left on top of the ice cube is still close to 0°C. As the salt
fully dissolves into the water in the cup, the water on top of the ice
starts to refreeze. As it refreezes, the string also gets frozen onto
the ice cube.
That which doth not mix
Materials
 Plastic cup
 Olive Oil
 Cold water
Procedure
 Pour the olive oil into the plastic cup so that the cup is
nearly half filled.
 Pour the cold water on top of the olive oil until it almost
reaches the top of the cup.
 Swirl the cup in a circular way and let it sit for ten minutes.
 Empty the plastic cup into the drain of a sink and throw
out the cup.
 What do you observe? Do the two liquids mix? What
happens as the two liquids are left to sit?
There are two reasons why olive oil and water do not mix. First, oil is
lighter than water, so when the heavier water is poured in it pushes
the oil up. This is because water has a higher density. Second, water
molecules tend to attract each other because they are charged.
Olive oil molecules are not charged at all, so the water will try to
stick together as much as possible.
Sink-a-Dime
Materials:
 Two identical drinking glasses
 One dime
 Large tub filled with big enough water to submerge both glass
cups on their sides at the same time
 Towel (for any spills)
Procedure:
 Fill the large tub with water
 Submerge both glass cups in the tub
 Press the rims of the cups together
 While keeping the rims together, take out the glasses and set
them the towel, with one glass resting freely on top of the
other
 Gently tap the top cup to slide it off of the bottom cup until
there is a space big enough to slide the dime into the bottom
cup
 Insert the dime into the bottom cup
Scientific Explanation
The water in the top glass didn‟t spill out all over the table because
water has a certain property called surface tension. Surface
Tension is the name given to the cohesion between molecules of a
liquid at its surface. Cohesion is the attraction of molecules of a
liquid to other molecules of the same liquid. The molecules in a
volume of water pull on the other molecules of water closest to
them, keeping them grouped together. The molecules on the
surface pull on each other, creating something like a sac that keeps
all of the molecules together. The bond angle, angle at which atoms
are bonded together in a molecule, of water is special and creates
strong cohesion between water molecules. It also creates strong
surface tension. It is strong enough to hold all the water in the glass
cup without it spilling out.
There are many other experiments demonstrating surface tension.
One of them includes counting the drops of water that may be
dropped on the top of a coin before the water spills over.
Air Takes Up Space
Materials





paper towels
1 medium sized clear plastic bowl/container
1 tissue
1 clear glass
1 ping pong ball
Procedure
 Fill the clear plastic container/bowl almost to the brim with
water.
 Place the ping pong ball into the clear glass.
 Overturn the glass with the ping pong ball in side of it onto the
water.
 Press the glass downwards a few inches. What do you notice
about the ping pong ball? What do you think is inside the glass?
 Remove the glass and ping pong ball from the container.
 Dry the glass thoroughly with a paper towel.
 Crumple up the tissue and put it into the bottom of the glass so
it stays.
 Overturn the glass into the water-filled container.
 Press the glass downwards a few inches into the water, making
sure that the tissue is still lodged within the glass.
 Remove the glass from the water, and keep it turned over as
you dry the outside of the glass with a paper towel.
 Carefully take out the tissue. What do you notice about it?
What does this tell you about what was inside the submerged
glass?
Air, just like any other form of matter, takes up space. We can see how
air maintains space when we observe how the insides of containers
behave when submerged in water; for example, when an upside down
glass that has air in it is pushed under water, the inside of the glass
doesn‟t fill up with liquid. This is because the air that is already in the
container when it is turned over stays inside of the container and pushes
against the water that is trying to get in. This is called air pressure, and it
comes from air molecules taking up space.
Gravity-free Water
Materials




1
1
1
1
glass cup
sink
index card (4” x6” )
shallow, clear glass or plastic bowl (not metal)
Procedure
1. Place the index card on top of the cup and flip it upside down.
2. What happens to the index card when it is flipped?
3. Filled the cup with water so that the water is at the brim. This
should be done at a sink because the water can spill while it is
being filled.
4. Place the index card over the top of the cup.
5. Press down on the card so it is touching the water in every part
of the index card.
6. Flip the cup upside down again.
7. What happened to the water? Why did the water not come out
of the cup and spill on the floor?
The water is held in the cup the second time because of air
pressure. The force of air pressure is shared through every part of
the air and pushes out in every direction. It pushes back against any
force, but we normally can‟t feel this. The weight of the water is
low enough so that the water is held up by the air
Under Pressure?
Materials
 1 plastic 1 liter soda bottle
 1 fun size snickers candy bar in wrapper
 About 1 liter of non-carbonated water
Procedure
 Remove the label and top of the bottle
 Fill the bottle with water until it reaches the top of the bottle.
 Push the snickers bar through the opening of the bottle. This
will be a tight fit, but it is possible.
 Tightly screw the bottle cap on.
 Squeeze the sides of the bottle.
 What happens to the snickers bar? What happens to the
wrapper of the snickers bar?
The physics of this experiment are based on the science used by
Cartesian divers. The snickers bar has a small amount of air in the
wrapper which causes it to be neutrally buoyant. This means that it
barely floats below the surface of the water and therefore the
snickers represents the diver. When pressure is applied on the sides
of the bottle, the water is able to evenly carry this pressure to the
diver. This causes the air within the wrapper to compress, resulting
in a higher density and less buoyancy. The diver proceeds to sink.
Capillary Action
Materials
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Tap water (hot and cold)
4 cups plastic 10 ounce cups
2 Paper towel sheets
Stop watch or timer
Procedure
 Fill one plastic cup with 8 ounces of cold water. Place an
empty cup ½ inch away.
 Fill another cup with 8 ounces of hot water. Place the other
empty cup ½ inch away.
 Roll each paper towel sheet separately into rope-like wicks.
 Place one end of a rolled paper towel into the cold water and
the other end into the empty cup.
 Place one end of the other rolled paper towel into the hot
water and the other end into the second empty cup.
 Time the two cups to see which transfers water into the
empty cup the fastest. What did you notice?
The water transfers between the two cups because of pores in the
paper towels. Theses air holes are called capillaries. When the pores
fill with water, the fluid progresses through the wick until gravity
can overcome the intermolecular forces of the water molecules.
The hot water travels faster than the cold water because heat
causes the kinetic energy of the water molecules to increase,
speeding them up. If left for an extended period of time, the water
in both cups will transfer into the empty ones until equilibrium is
reached (the level will be the same in all four cups).
Air Currents: Heat Rises
Materials
 votive candle
 matches
 tall plastic cylinder (one open end)
Procedure
 Set a votive candle on a flat table top and light it.
 Place a clear plastic tube with a small hole in the top over the
candle and wait 15 seconds. Notice how the flame has gotten
smaller.
 Lift the tube a little so that one side of the bottom is still
touching the table. Notice how the flame grows.
We know that fire needs oxygen in order to stay lit. With that,
you might think that the small hole in the top of the tube provides
an inlet of oxygen to feed the flame and sustain it; however, this
assumption neglects one key factor which is the point of this
experiment. Heat rises. Why? The difference between hot air and
cooler air is the amount of energy the atoms have. Hot air
molecules have more energy (making them hot) and the more energy
the atoms have, the faster they move around thus taking up more
space even though there‟s the same amount of atoms. This makes it
less dense and lower densities “float” on top of higher densities.
Now that we know why heat rises, we can understand that the
rising heat from the candle in the cylinder of this experiment flows
through the hole in the top. This air current prevents enough air
from entering into the tube through the hole. This means that the
flame will only stay lit until the oxygen in the tube runs out and then
it will go out. Lifting the tube allowed air to flow up into the tube,
rather than fighting through the small hole and it fed the flame to
make it grow again.
Air Pressure
Materials
 1 potato
 2 straws
Procedure
 Take the straw and make sure that the top hole that will not
be injected into the potato is not covered.
 Insert the other end of the straw into the potato. Can it be
inserted into the potato?
 Remove the first straw from the potato and take the second
straw. Take the second straw and this time make sure that
the top is covered.
 Inject this straw into the potato. Can this straw go through
the surface of the potato?
 Remove this straw from the potato.
Air pressure is the main factor that affects this experiment. When
trying to insert the first straw into the potato (when the hole is not
covered), it will not go into the potato. This is because the air
molecules freely pass through the straw and do not put pressure on
the potato. The straw alone is unable to break through the surface
of the potato. When the hole is covered on the straw, the air
molecules inside are compressed, increasing the pressure. This
increase in pressure puts more pressure on the potato when trying
to insert it into the potato. The pressure keeps building up until
eventually the straw has to go through the surface of the potato
due to an overload in pressure.
Candles and Air Pressure
Materials
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Pan
Water
3 birthday candles
Aluminum foil
Clear glass cup
Matches
Procedure
Fill pan with just enough water to cover the bottom.
Mold aluminum foil holder for candle.
Place candle and holder in the pan with the water.
Light the candle.
Place glass upside down over candle.
Observe the changing water levels within the glass.
Once water is absorbed measure height of water within the
glass.
 Repeat step 2-7 twice adding an additional candle each time.
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Fire needs oxygen to burn. When the candle is covered with
the glass, it is no longer receiving that required oxygen. This creates
a lower concentration of pressure inside of the cup. The pressure
outside the cup can then push the water up. The dying candle flame
is also responsible because it cools the air. Hot air expands and cold
air contracts. If the air contracts, there will be more space in the
cup that the water can consequently fill.
Humpty Dumpty Had a Great
Fall…
Materials
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1 hard-boiled egg
small piece of scrap paper
matches
glass milk bottle
Procedure
 Peel the egg.
 Light a small piece of paper with a match and drop the paper
into the milk bottle.
 Place the peeled egg on top of the bottle and watch what
happens.
Air molecules move farther apart when they are heated and
this causes air to expand. While the fire is burning in the bottle
without the egg on top, air is allowed to expand and escape. When
the egg is placed on top, it traps the expanded air. Air condenses
when it cools. As the air condenses, space needs to be filled inside
the bottle and so a vacuum is created. The egg is pulled into the
vacuum and falls into the bottle.
Oobleck
Materials
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1 sheet of newspaper
1 gallon-sized Ziploc bag
1/4 cup water
1 plastic spoon
1/3 cup cornstarch
1 magnifying glass (optional)
Procedure
Spread the newspaper out so that you don‟t make a mess!
Take the 1/3 cup of cornstarch and put it into the Ziploc bag
Now add the 1/4 cup of water and add it to the Ziploc bag
Take the spoon and mix the cornstarch-water mixture until it
becomes gooey.
 Close the Ziploc bag.
 Take your fist and punch the Ziploc bag with the solution.
Don‟t hurt yourself! Use a magnifying glass…what do you see?
Is this a solid or a liquid?
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 Take your finger and jab it (without hurting yourself!) into the
solution. What do you see (use a magnifying glass)? Is this a
solid or a liquid?
 Take your finger and dip it slowly into the Ziploc bag solution.
What do you see (use a magnifying glass)? Is this a solid or a
liquid?
The substance that it formed is sometimes called a „so-quid‟
because it displays properties of both solids and liquids. Oobleck is
actually a special type of liquid in which all parts of the substance
are not flowing at an equal rate. Because the viscosity of the liquid
is different, it sometimes has qualities of being a solid and liquid.
Oobleck
Materials
 1 ½ cups cornstarch
 1 cup warm water
 Shallow Plastic container
Procedure
 To create the oobleck, mix the cornstarch and the warm
water, in the plastic container, until all the cornstarch has
dissolved in the water.
 Punch the oobleck and record what happens. Does your fist
sink into the oobleck at all?
 Next, put your hand on top of the oobleck and allow it to sink
in, then try to take your hand out of the oobleck quickly. Why
do you think you are able to sink into it this time?
 Using your finger, cut a line in the oobleck. Look through a
magnifying glass as the oobleck re-forms itself.
 What did the oobleck look like when you initially cut it?
 How did that shape change as the oobleck returned to its
previous shape?
 Roll the oobleck into a ball. Can you make it into a round
shape?
 Hold the ball in your hands for a little while. What happens to
the shape?
As you saw from the experiment, oobleck acts like a solid when you
work with it quickly, and acts like a liquid when you work slowly.
The reason for this is because of the molecules that make up
cornstarch. Molecules are the building blocks of most substances
and are too tiny to see with your eyes or even a magnifying glass.
The molecules in the cornstarch are starches called amylose. The
amylose is made of long chains of atoms, which are even smaller
than molecules. When you mix the cornstarch with the water, the
amylose molecules get all mixed up in the water. When you put
pressure on the water quickly, the molecules get all tangled up and
don‟t let your hand through. When you put pressure on the oobleck
slowly, the amylose molecules are able to move away and let your
hand through. This makes the oobleck feel more like a solid.
Cornstarch, Water, and
Oobleck
materials
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Measuring cup (1/2 & 1 cup)
Cornstarch (2 cups)
Water (1/2 cup)
Large container or mixing bowl
Spoon
3 Plastic baggies (re-sealable)
Procedure
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Pour 2 cups of cornstarch into the mixing container.
Pour ½ cup of water into the mixing container.
Stir mixture with a spoon until it is a consistent fluid.
Scoop the putty into three separate baggies.
Seal the baggies shut.
Pass out the baggies.
Oobleck is a perfect example of a non-newtonian fluid. NonNewtonian fluids are thicker in some areas and thinner in others.
Oobleck is made up of long chains of atoms. These chains are called
polymers. Although the polymers are able to slide past each other, it
takes a long time for them to do so. If the oobleck is left alone, it will
flow like a liquid. However, if it is hit, the polymer chains will become
tangled, and the oobleck will appear to be solid.
CO2 Fire Extinguisher
Materials:
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1 liter volume glass bowl
3 tbsp baking soda
Two tea light candles
Matches (or a lighter)
1/8 cup white vinegar
Paper Towels
Procedure:
 Pour the 3 tbsp of baking soda into the bottom of the bowl.
 Shake the bowl in a clockwise motion to evenly distribute the
baking soda across the bottom.
 Place the two candles, wick side up into the bowl as close to
the center as possible.
 Light the two candles and wait for about 10 seconds.
 Pour the vinegar into the bowl (not onto the candles, just the
baking soda)
 Observe what happens to the flames.
The Scientific Explanation:
Reacting baking soda and vinegar (commonly used in “volcano”
type experiments) produces the CO2 , or (carbon dioxide) gas. This
gas is heavier than air, and therefore it sinks to the bottom of the
bowl, replacing the oxygen that once occupied that space. This new
CO2 gas puts out the flame because flames need oxygen to burn –
oxygen that was displaced by the CO2.
Shrinking Water Bottle
Materials
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1 empty .5 liter water bottle
1/2 cup of water
thermometer
any water heating device
Procedure
 Heat up the half-cup of water until it reaches a temperature
of 152 degrees Fahrenheit (67 degrees Celsius), so that the
water starts to steam. Be careful when handling the hot
water; you may need an adult to help you.
 Allow the water to cool if it is too hot to handle, and then
pour it into the empty bottle.
 Allow steam to collect in the bottle for 10 seconds.
 Unscrew the cap for a couple of seconds to let out the steam,
and then quickly replace the cap.
 Allow the water inside the bottle to cool for ten minutes.
 Observe the bottle as it cools and record anything you notice
about the bottle‟s shape.
If you have ever seen party balloons left out overnight, you may
notice that the balloons are smaller in the morning. You may even
notice the balloons becoming larger during the day. When
substances are warmed, the particles in those substances expand,
and take up more space. As the objects cool the particles take up
less space. This experiment shows a similar situation using a water
bottle. When you release the steam from the bottle, there is less air
inside the bottle, and the particles are just moving around quickly
enough to keep the bottle full. As the water cools, the air inside
the bottle takes up less space, and the plastic contracts. If you
were to reheat the bottle, it would regain its original shape.
Friction !
Materials
 2 large telephone books such as Yellowbooks
Procedure
 Work in pairs.
 Put the Yellowbooks next to each other.
 Layer the pages of one Yellowbook into the second
Yellowbook one page apart.
 Continue layering as many pages as possible (200 pages would
be enough to overcome the pulling power of 2 children).
 Lift the Yellowbooks and try to pull them apart.
 Did the Yellowbooks give in?
Friction is a force that does not allow an object, which
touches another object, to move freely. Friction between the pages
does not allow the books to be pulled apart. The more pages are
interlocked, the greater the area of contact between the
Yellowbooks. If all the pages were put on top of each other one
page apart, it would take over 8000 lb of force to pull them apart,
which is equal to 2 tanks pulling with full force. If only a couple of
pages were put together, friction would be much less, allowing the
pages to be pulled apart.
Sliding Vs. Rolling Friction
Materials
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Spring Scale (measures force)
Reading Book (about 3 pds)
White Lined Paper
8 Thick Markers
Masking Tape
Plastic Ruler
Scissors
Pencil
String
Procedure
 Gather the materials for the experiment (small reading book,
string, duck tape, scissors, spring force scale, pencil, paper, 8
thick markers and ruler) on a table.
 Make a chart on the piece of paper with the pencil. Make two
columns with “Sliding” as one title and “Rolling” as another
title. Each column should have two rows (title -> data).
 Lay book face down on the table.
 Measure a 4 inch piece of string with a ruler and then cut the
piece of string with scissors.
 Measure a 1 inch piece of duck tape with a ruler and then cut
the piece of tape off with scissors.
 Tape 4 inch piece of string to the book so the edge of the
string is a half of an inch away from the edge of the book.
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The rest of the 3 and half inches of string should be hanging
off the edge of the book.
Make a small loop on the edge of the string hanging off the
book with a standard knot.
Hook the bottom hook of the spring scale to the knot of
string.
Pull gently on the top part of the spring scale as you pull the
book across the table.
As you are sliding the book across the table, read the amount
of force (in Newtons (N)) on the spring scale. This is the
amount of force necessary to slide the book across the table.
Record the force in the data column under “Sliding”.
Now complete the same procedure but with the 8 markers
spaced evenly under the book
As you roll the book on the markers read the amount of force
(in Newtons (N)) on the spring scale. This is the amount of
force necessary to role the book across the table.
Record the force in the data column under “Rolling”.
Compare and Conclude: Which method of moving the book
took less force?
Generalize: For any object, is it easier to slide or role the
object across a flat surface?
The focus of this experiment is on the advantages of rolling an
object rather than sliding an object. To get an object moving a
force is needed. At the same time, friction is pointing in the
opposite direction of the motion direction/force of the object.
Friction is the resisting force to the motion of the object.
This project focuses on kinetic friction and the force it takes to
keep the object in motion. The more kinetic friction the more
force needed to keep an object moving. Rolling an object is easier
than sliding an object because there is less force required to roll an
object than slide an object. This is because there is less kinetic
friction involved with wheels and rollers than sliding surface to
surface. Not as much force is needed to keep the object mo
Burning Money
WARNING: Burning U.S. currency is against the law. The bills used in this experiment should not sustain damage if the procedure is done
correctly, but proceed at your own risk.
Materials
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2 disposable aluminum pie pans
A small bottle of isopropyl (rubbing) alcohol
Measuring spoons or cups
A small candle
Matches
Metal tongs
U.S. $1 bill (other denominations or “linen” paper will also work)
Procedure
(Note that this is made for teachers to give as a demonstration; it is
not safe for students to conduct)
 Prepare a solution of 50% isopropyl alcohol and 50% water,
keeping in mind that the alcohol from the bottle is likely to be
partially diluted with water already. You will only need enough
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solution to cover the bottom of one pie tin to conduct
multiple demonstrations.
Set the pie tins up side by side with the alcohol solution in one
of them and the candle in the other.
Place the dollar bill flat in the alcohol solution and let it soak
until saturated; this should not take more than 15 seconds.
While the bill is soaking, put the candle in the center of the
empty pie tin and use the matches to light it (be wary of
setting the alcohol solution on fire).
After the bill is soaked, use the tongs to pick up the bill and
hold it over the alcohol solution for a few seconds to let the
excess solution drip off.
When the bill has mostly stopped dripping, swing it carefully
over to the candle and touch a corner to the flame.
The flames will grow rapidly and burn for a couple seconds
once ignited, then quickly subside. Take care to ensure that
the flames completely extinguish. It will take around 5 seconds
from lighting the flames until they should extinguish, any
longer and the bill itself is probably on fire and should be
extinguished.
The reaction of the alcohol and oxygen in this experiment is a
combustion reaction represented by the following equation:
C2H5OH + 4 O2 -> 2 CO2 + 3 H2O + energy
The alcohol has a high vapor pressure relative to water and thus
moves towards the top of the solution, effectively coating the
water, which is in turn coating the bill. When the alcohol combusts,
the heat energy it releases is not enough to evaporate the water.
The bill is insulated from the heat by the water and does not reach
a high enough temperature to combust. When all of the alcohol has
combusted, the waterlogged bill is unharmed.
In simple terms, the water coats the bill and insulates it from the
alcohol. Since water does not burn, the money will not either even
though the alcohol around it will. The flames you see are the
alcohol burning, not the money.
Rubber Band Car
Materials
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Corrugated cardboard
4 CDs
4 ¼ inch washers
2 wooden skewers
Poster putty
Rubber band
Scissors
Ruler
Procedure
 Cut a five inch by six inch rectangle from the cardboard.
 Cut a notch 2 inches wide and 1 1/2 inches deep in one of the 5
inch sides of the foam board rectangle. This notched end will
be the front of the rubber band car.
 Slide a wooden skewer through the cardboard near front of
the car. Slide another wooden skewer was slid through the
back of the car. Make sure that the skewers are parallel to the
front edge of the car and stick out approximately the same
distance on either side of the car.
 Twist the skewers around until they are able to rotate freely.
 Hold a washer to the center of a CD and slide them onto the
end of a skewer. Leave a little room between the CD and the
cardboard.
 Use poster putty to hold the washer to the CD and to secure
the whole wheel to the axle.
 Glue or tape a rubber band to the cardboard a little bit behind
the notch. Stretch the other end of the rubber band over the
front axle and the twist the wheels until the rubber band is
tight (but not too tight – you don‟t want it to snap).
 Place the car on the ground and release the wheels.
 Watch the car move forward!
Potential energy is stored energy, while kinetic energy is motion. As
you wind the rubber band around the wheels, potential energy is
stored in the rubber band. When the rubber band is released and
unwinds, the stored potential energy is converted to kinetic energy
and the car is propelled forward.
Laws of “Attraction”
Materials
 A plastic comb or ruler
 A faucet with running water
 A test subject with hair (it can be yourself!)
Procedure
 First, go to a sink and turn the cold knob until a slow and
steady stream of water is pouring out.
 Then, take the plastic ruler and run it through your hair
twenty to thirty times
 Now, making sure not to touch the ruler to anything, slowly
move the edge of the ruler, which is farthest from your hand,
towards the running water that is near the bottom of the sink.
 Watch as the water starts to bend toward the ruler! Why do
you think that works?
Well, everything that you see around you is made of lots and lots of
tiny little things called atoms. Each of these atoms has protons,
which are positively charged, and electrons, which are negatively
charged. When the atoms of an object have more electrons, then
the object also has a negative charge. When the atoms have more
protons, then the object is positively charged. Things that have
opposite charges are attracted to each other. When you run the
ruler through your hair, it makes some of the electrons in your hair
“jump” to the ruler. That causes the ruler have more electrons,
which means it has a negative charge. Water is made of groups of
two hydrogen atoms and an oxygen atom which have combined to
make molecules. Each water molecule has a positively charged side
near the hydrogen and a negatively charged side near the oxygen.
The positive sides of the water molecules are attracted to
negatively charged things, like the ruler. Because of this attraction,
the water bends when the ruler moves closer to it.
Electrified Dice
Materials
 Glass sheet, about 8 inches by 10 inches
 Two thick books
 Five foam cubes, the size of dice
 Felt-tip pen or permanent marker
 Piece of wool
Procedure
 Place two books on the table, about 8 inches apart
 Place the glass sheet between the pages of the book so that it
is about 1in above the table
 Draw dots on the foam cubes using a felt tip pen or permanent
marker in order to make them look like dice
 Place the “dice” underneath the glass
 Rub a piece of wool back and forth on the surface of the glass
 Notice the movement of the dice even after you stop rubbing
the glass
When you rub the wool on the glass, you are generating what is
called static electricity. This causes a charge to build up on the
glass. The foam dice don‟t have a charge, but they are still
attracted to the charged glass. This attraction causes the dice to
have an excited state, which makes them move around. Even after
you stop rubbing the wool over the glass, the charge stays for some
time.
Bending Water
Materials
 Latex balloon
 Faucet with running tap water
 Stop watch or a clock with the seconds hand
 A volunteer with long hair
Procedure
 Blow up the latex balloon
 Using a volunteer from class, rub the balloon in his/her hair for
about 45 seconds. Make sure the balloon doesn‟t touch
anything except the hand it is held in
 Turn on a faucet so tap water is running in a thin stream
 Bring the side of the balloon that was rubbed in hair close to
the water and watch as the water bends towards the balloon
 Does the water bend more if the balloon is closer or farther
away from the water? What if the stream of water is thicker?
What if the balloon was never rubbed in hair?
 Always make sure to check for latex allergies before bring a
latex balloon into class. If there is a latex allergy, a hard plastic
comb can be used instead.
Some objects, such as magnets, have a charge. This means that
they attract other charged objects, such as other magnets. This
explains why if you put two magnets near each other, they will pull
together. Water molecules are like magnets. They are attracted to
each other. This explains why water forms droplets. Balloons are
not normally charged, so if you bring a balloon that wasn‟t rubbed in
hair near water, nothing happens.
Hair has the potential to charge a balloon. When you rubbed
the balloon in your classmate‟s hair, the balloon became charged
just like a magnet or a molecule of water. When the charged balloon
was held near the water, the water and balloon were attracted to
each other. Because you were holding on the balloon, it wasn‟t able
to pull towards the water, but the water was easily pulled towards
the balloon.
Fun with Static Electricity
Materials
1 tissue
1 Piece of printer paper
a pair of scissors
a ruler
any one of the following materials: cotton cloth, wool cloth,
nylon cloth, animal fur, human hair
 a clock/watch/timer
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Procedure
 Cut 3 squares out of the tissue. One .5 by .5 inch, one 1 by 1
inch, and one 2 by 2 inch.
 Now, cut 3 square of the same size out of the piece of printer
paper.
 Place the squares onto a dry surface. Make sure that they are
at least one inch apart.
 Rub the comb against the cloth/fur/hair for 10 seconds.
 Immediately touch the comb to the .5 by .5 inch tissue square
and lift the comb into the air. Record how many seconds that
the tissue remains in the air.
 Rub the comb against the cloth/fur/hair for another 10
seconds.
 Now, touch the comb to the 1 by 1 inch tissue and lift the
comb. Record how many seconds that the tissue remains in the
air.
 Repeat this process with the 2 by 2 inch tissue square and the
various sized printer paper squares.
 What effects did the size and type of paper have on the time
that the paper squares remained in the air?
All objects are made up of tiny particles called atoms. In each atom,
there are even smaller particles called protons and electron. Atoms
of different objects can exchange electrons, which causes a change
in the balance of protons and electrons. An object that has more
protons than electrons has a positive charge, and an object that has
more electrons than neutrons has a negative charge, and n object
that has an equal number of protons and electrons it has a no
charge and is called neutral. Objects with like charges repel each
other, objects with opposite charges repel each other, and an
object with any charge will attract an object with no charge
(neutral). In this experiment, the comb was given a charge when it
was rubbed with another material (whether it was positive or
negative depends on the material that the comb was rubbed
against). When the comb was charged, it is said to have static (not
moving) electricity because the comb had electricity from the
charging, but the electricity was not allowed to flow because the
comb is an insulator (an object that does not allow the flow of
electricity). Because the comb was charged and the paper was
neutral, the comb was able to pick up the paper through electrical
attraction.
Charge for Cheerios!
Materials






scissors
thread
10-20 Cheerios or other doughnut-shaped cereal
balloon
sweater
tape
Procedure
 Measure and cut a twelve-inch piece of thread and tie one
end of it through a piece of cereal.
 Tape the other end of the string to a table so that it does not
hang near any other objects
 Blow up a balloon and rub it against a sweater for one or two
minutes to produce static electricity around the balloon.
 Lift the balloon and slowly move it towards the piece of cereal
that is hanging off the side of the table. Watch the piece of
cereal. Does it move towards the balloon?
 Hold the balloon in place until the piece of cereal moves away
from the balloon on its own.
 Move the balloon near t he piece of cereal once again and
observe the piece of cereal. It moves away from the balloon
this time, right?
The transfer of electrons, or negatively charged particles, takes
place within a small electrical current, which produces a very small
electric shock. When you generate static electricity between the
sweater and the balloon an electric shock is produced and
electrons are transferred from the sweater to the balloon. This
transfer of electrons results in the balloon having a greater number
of electrons than it previously had, giving it a new negative charge.
When you move the balloon towards the piece of cereal, electrons
are once again transferred to the cereal, which is why it is
immediately attracted to the balloon. However, once the piece of
cereal gains a certain number of electrons it then has the same
charge as the balloon and the two objects repel each other.
Magical Magnetism
Materials





60-70 paperclips
1 bar magnet
1 horseshoe magnet
1 circular magnet
1 inch piece of magnetic tape
Procedure
Lay the paper clips out on the table.
Hold the bar magnet above the table.
Hold paperclips against the magnet until the paper clip stays.
Put more paperclips on the magnet until no more paperclips will
stay.
 Take the paperclips off of the magnet.
 Count the number of paperclips and write it down.
 Then, repeat steps 1-7 for the other magnets.




Light fro ht
Magnets have two poles, north and south. North poles repel north
poles and attract towards south poles. South poles repel south
poles and attract north poles. Magnets produce a magnetic field
that extends out from the north pole and curves back towards the
south pole. Within its magnetic field, a magnet can affect other
materials. For example it can hold paper clips when they are within
the magnetic field.
As a further experiment hold a magnet under a piece of paper and
pour iron filings on the paper. The filings will be pushed into a
pattern. The pattern the filings are in shows the edge of the
magnet‟s magnetic field.
Make an Electromagnet
Materials






An iron nail, preferably 6” or longer
A spool of insulated wire
Scotch tape
Wire strippers
AA battery
Paper clips or other small metal objects
Procedure
 Strip the insulation from the end of the wire, and tape it to
the head end of the nail, keeping some length of wire between
the end of the wire and the nail.
 Begin coiling the wire down the nail. Try to wrap the coils
together as tightly as possible.
 When you get close to the tip of the nail, start coiling the wire
back up the nail (it‟s okay to make coils on top of each other).
Finish coiling when you make 2 or 3 layers of coils.
 Tape the final coil down and cut the wire from the spool.
Make sure you have enough wire to connect both ends to the
battery. Strip the insulation from this end as well.
 Tape the ends of the wire to the ends of the battery. If the
battery starts to get very hot, remove one end from the
battery for a while.
 Move the tip of the nail near the paper clips. They should be
magnetically attracted to the nail.
 Experiment:
a. What happens when you use more layers of coils (4, 5, 6,
or more)?
b. What happens when you use fewer layers of coils (1 or 2)?
c. What happens when you switch which ends are attached
to which ends of the battery?
Magnetism is caused when electrons move. Electrons are spinning in
all objects, but a magnetic field is only created when they spin in the
same direction. When this is the case, the object is called a
permanent magnet. Electromagnets, on the other hand, are formed
by a coil of wire. When electricity travels through the coil, a large
number of electrons are traveling in the same direction, so a
magnetic field is formed. This is the case with this experiment.
Floating Paper clip
Materials






String
Magnet
Scissors
Paper clip
Scotch tape
Clean glass jar with lid
Procedure:
 Take the scissors and string. Cut a piece of string about the
length of the jar.
 Next, tie the string to the paper clip with a simple knot. The
string and paper clip should now be a little less than the length
of the jar. (It may be necessary to cut off some of the extra
string).
 Take a piece of tape and wrap it around the end of the string.
 Take a second piece and make it double-sided (so both sides
are sticky). Place one side on the bottom of the jar.
 Place the string and paper clip onto the other sticky side of
the tape on the bottom of the jar.
 Take the magnet and tape it to the lid of the jar.
 Now, secure the lid and turn the jar upside down. The string
hangs down near the magnet. Now turn it right side up again
and notice what happens to the string. It will be suspended in
mid-air.
The paper clip, as you saw, looks like it is floating in mid-air.
This is due to the force called magnetism. Objects have a magnetic
field around them. This is an area around an object that is created
by an electric current. The magnet has a magnetic field that
attracts the paper clip. The magnet has both a north and south
pole, which are just the opposite ends of the magnet. If you had a
second magnet, the north pole of that magnet would attract the
south pole of the first magnet, and the south pole of the second
magnet would attract the north pole of the first magnet. Two north
poles would not be attracted to each other. Also, two south poles
would not be attracted to each other. The paper clip does not stick
directly to the magnet only because the string holds it back.
Somewhere Over the Rainbow
Materials:





a small mirror
a piece of white paper or cardboard
water (H2O
a container: a large shallow bowl or pan
a flashlight
Procedure:
 Fill up the pan or bowl with water until the water is about an
inch from the container‟s rim.
 Place the container on a flat surface like a table or the floor.
 Turn off the lights in the room and close the blinds if possible.
 One person should hold the mirror in the water at about a 45o
angle.
 A second person should hold the white paper in front of and
above the container. Another person should turn on the
flashlight and shine it on the mirror in such a way that the
reflection of the light shines onto the piece of paper. Notice
the rainbow that appears on the piece of paper.
Many people have seen a prism. A prism splits light into the colors
of the rainbow. In this experiment, light is passing from the water to
air, which causes its speed and direction to change. This is called
refraction. It causes the colors of the rainbow to become apparent.
Sky in a Jar
Materials






a clear, straight-sided drinking glass or jar
1 cup of water (H2O)
1 teaspoon milk
flashlight
measuring spoons
a darkened room
Procedure
 Fill the glass or jar with 1 cup of water.
 Add 1 teaspoon of milk and stir until the milk and water are
thoroughly mixed.
 Turn off the lights in the room and shut the blinds if possible
or bring the glass and flashlight into another room.
 Hold the flashlight above the surface of the water with the
light shining on the water and observe the water in the glass
from the side. What color is the mixture?Hold the flashlight to
the side of the glass and look through the water directly at
the light. What color do you see now?
 Put the flashlight under the glass and look down into the
water from the top. How did the color change?
The small particles of milk suspended in the water scattered
the light from the flashlight, like the dust particles in the air
scatter sunlight. When the light shines on the top of the glass, the
water looks blue because you see blue light scattered by the milk.
When you look through the water directly at the light, it appears
red because the blue light hits the cup at an angle and has more
water to pass through. This scatters the blue light more, but the
red light travels straight through the water. Blue light has a shorter
wavelength than red light. In the sky, the longer wavelengths pass
right through all particles. The shorter wavelengths, like blue light,
are scattered by the particles and reflected back to earth at all
different angles. When the light is scattered in all different
directions, it can be seen from everyone on earth which makes the
sky look blue.
Making a Rainbow!
Materials





Flashlight with Battery
Small Mirror
White Wall or several sheets of white paper and tape
Water
Container with large base(cereal bowl/baking pan)
Procedure
 Place a container near a white wall (if you are using paper tape
white paper on to the wall.)
 Take the container and you use and fill it with water until it is
three quarters of the way full.
 Take a small mirror and place it in the bowl so some of the mirror
is in water and some of it is not. Make sure the mirror is facing
away from the wall.
 Now shine the flashlight so the light is shining on the part of the
mirror that is out of the water, and the part of the mirror that
is out of the water.
 Now turn off the lights to the room and close the shades
 Observe a rainbow on the wall
 Once you are finished take the mirror out of the bowl and pour
the water out of the bowl into a sink. Also turn the flashlight
off.
A rainbow is normally caused right after there has been a lot
of rain and the sun is out. A rainbow is an arc of light that is
separated into multiple parallel stripes of color. The water droplets
that are still in the air after a rain shower interact with the sun‟s
light rays by bending it and reflecting it. This process makes the
white light rays the sun gives out into a whole spectrum of colors
that is known as a rainbow. The colors of a rainbow are red,
orange, yellow, green, blue, indigo, and violet (in that order).
In this experiment the same science is being replicated to form
a rainbow, and the scientific explanation is the same, except
instead of the sun, the light from a flashlight is being bended and
reflected by the water in the bowl. The rainbow is then shown on
the wall.
The Water Drop Microscope
Materials






Small flashlight, headlamp, or similar
Clear plastic container (ex: a Rubbermaid container)
Thin piece of metal (aluminum, 1 by 5 inches)
Scotch tape
Water
Anything you want to look at under the microscope
Procedure
 Place the lid of your container upside down on the table, turn
on your flashlight, and place your flashlight on top of the lid so
that it is aiming straight upward.
 Enclose the flashlight within the container by lowering the main
body of the container over it and attaching it to the lid
underneath.
 Drill a small (3/16 inch) hole in the piece of aluminum centered
about a ½ inch from the end of the piece.
 Bend the aluminum into a right angle 1½ inches from the end the
hole was drilled near.
 Tape one end of the piece of aluminum to the container so that
the hole on the other end is centered about 1 inch over the top
of the container.
 Place a drop of water in the hole in the aluminum. The drop will
stay there suspended.
Notes


The aluminum may have to be moved up and down or bent up and down to focus the
microscope.
Make sure that the light is not too bright or it might make the object being viewed
look very blurry.
A lens in a microscope works as shown in the image below. They
redirect the light that passes through them into one point, and
when the light passes that point, it spreads out again. The water
drop, when suspended as it is in your water drop microscope, is
pulled downward by gravity into the shape of a lens, but does not
fall out if the hole because it is held there by the surface tension of
the water. Because it is in the same shape as a lens and light can
pass easily through water, the drop works just like a lens does.
Pendulums
Materials






Strings measuring 3, 4, & 5 ft
Box of paper clips
Timer
Open doorway
Yard stick
Masking tape
Procedure
 Mark a line three feet from the doorway.
 Tie loops at both ends of each string and distribute them equally
across the top of doorframe, taping them with the strings
hanging down.
 On each of the bottom loops, place two paperclips.
 Bring one string back to the line and release it, timing the
period. Do this for each of the strings.
 Add two more paperclips and repeat step 4. Continue adding
paperclips and timing the periods until there are eight paperclips
on each string.
 Create a table comparing the weight and period length for each
length string.
 How does weight affect the period? How does length affect
period? If you wanted a longer period, would you change length
or weight and would you add it or subtract it?
Pendulums swing because of gravity. When you release the bob,
gravity pulls it down as far as possible. Then the momentum of the
bob keeps it swinging up the other side. Because all objects fall at
the same rate, the weight of the bob doesn‟t affect the period. But
if the pendulum has a longer string, it can
travel further and takes longer to
complete a period.
Definitions
Bob- the weight at the end of the pendulum
Momentum- the tendency that any moving object has to keep going
unless something stops it
Period- which is the length of time the bob takes to swing back and
forth once

A Book of Experiments

Transcription

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