Student Reports #2

Winter 2004

Donna Caspio

Plastics Breakthrough

Time: 15-20min

# Materials needed

• Water
• Paper towels (if needed)
• Zip-closing plastic bags
• Pencils/pens

# Experiment

1. Fill the plastic bag about ¾ full of water and close the bag tightly
2. Hold the bag over the sink or outside. (WARNING: if pencil tip is sharp handle with care and adult supervision)
3. Push the point of the pencil through one side of the plastic bag and into the water.  Did any of the water spill?
4. Look closely at the plastic bag around the pencil.  How would you describe the way the plastic bag fits around the pencil?
5. Do you think the pencil can go all the way through the water and out the other side of the bag without any water spilling? Slowly push the pencil all the way through the other side of the bag! Did any water spill now?

What’s is happening?

The flexibility and moldability of plastics allows them to cling to surfaces and fit tightly around or inside many different shapes.  Some plastics have carbon fibers in them which makes them lightweight and stronger than steel!  These plastics are used in racing bicycles, tennis racquets, and even airplane bodies.

1.      Can you think of any special uses for this type of plastic?

2.      What products do you think could be made from this plastic so that the contents will not leak even if it is punctured?

Reference: “The Best of WonderScience” p. 192

# Salt Volcano – Miniature “Lava Lite”

Strategy: in pairs or small groups

Time: 10 – 15 min.

Overview:

Density is a measurement of how much a given volume of something weighs.  Things that are less dense than water will float in water; and, things that are denser than water will sink.  In this particular activity, students will learn about Lava Lite.  The “lava” in a Lava Lite doesn’t mix with the liquid that surrounds it.  When it’s cool, the “lava” becomes a little be denser than the liquid surrounding it.  When it rests on the bottom of the Lite, the light bulb in the lamp will warm it up.  As it warms up, the lava slowly expands.  Finally, when it’s warm enough, the lava becomes less dense than the liquid and thus rising up to the top to float.  When it’s at the top, it cools down and sinks again.  The cycle will continue to repeat.

Purpose:

Students will gain a better understanding about density, why certain objects float or sink.

Materials:

• A glass jar or plastic drinking cups
• Vegetable oil
• Salt
• Water
• Food coloring (optional)

Procedure:

1. Pour about 3 inches of water into the cup.
2. Pour about 1/3 cup of vegetable oil into the cup.
3. Add one drop of food coloring to the cup.
4. Shake/sprinkle some salt on top of the oil while you count slowly to 5.
5. You may add more salt to keep the action going for as long as you want.

1.       When you poured the vegetable oil into the cup and as everything settles, is the oil on top of the water or underneath it?

1. What happened when you added one drop of food coloring into the cup?  Was the drop in the oil or in the water?  Does the color spread?
2. After you sprinkled the salt, what happened to the food coloring?  And the salt?

------------

1. Why does the oil float on the water?
2. What happens when salt is poured on the oil?
3. How does a Lava Lite work?

Conclusion:

In the following activity, students will have learned that oil floats on water because it is lighter than water.  Thus, water is denser than oil.  They will also learn that salt is heavier than water.  Therefore, when they poured salt on the oil, it sank to the bottom of the cup, carrying a blob of oil with it.  As the salt started to dissolve, it released the oil, which then floated back up to the top of the water.

Brandi Soto

BERNOULLI EFFECT

Area of Science: Physics

Strategy: In pairs

Time: 15-20mins

# Overview

Ever wonder what helps an airplane fly? Airplanes use the air moving over the wings to help five them lift. This is called the Bernoulli Effect.

# Purpose

To teach the students how the Bernoulli Effect is used.

Paper

Scissors

Transparent tape

Ping-pong Balls

Ruler

# Procedure

1. Using the ruler, measure and cut out strips of paper about 2 inches wide and 6 inches.
2. Hold the shortest end just under your mouth, and blow over the paper. What happened? What do you think will happen if you change the size of the paper? Do you think the shape of the strip of paper is important? Try experimenting! Do you think the experiment will always work?

Swinging Ping-Pong Balls

1. Use the ruler and scissors to measure and cut two thin pieces of string 12 inches long.
2. Take a piece of string and tape one end of the string to a ping-pong ball.
3. Tape the other end of the string to the ruler.
4. Take the other piece of string and another ping-pong ball and repeat steps 2 and 3. The ping-pong balls should be hanging about one inch apart on the ruler.
5. Hold the ruler up so the balls hang freely.
6. What do you think will happen if you blow in between the two balls?

# What is happening

Most people are surprised when the paper strips actually rise up! This is because of the air you blow is moving faster that the air underneath near the bottom of the paper. This means there is more pressure underneath the paper than on top.

The same thing happens with the ping-pong balls. When you blow in between the two balls, the fast-moving air helps pull the balls closer together. The air traveling over the curved surfaces of the balls is faster, and therefore has less pressure than the air on the outside of the balls. Both balls move to where there is less pressure, so they move toward the middle and get closer together. The air pressure on the outsides does not increase, by the pressure in the middle decreases, making the balls swing toward each other.

Sound Pitches

Julie Halferty

Purpose: This experiment will give insight to how frequency affects the pitch of sound.

Materials needed: Soda cans (preferably one per person), and pencils.

Activity:

1)      Ask each student to bring a can of soda to school prior to the demonstration.

2)      Give a brief lesson on how the pitch of a sound acts by how rapidly the object giving off sounds vibrates.

3)      Divide the students into groups with their cans.

4)      Either have them poor out a certain amount, or drink a certain amount of the soda.  Each student should have a different amount of liquid left in their can after this procedure.

5)      Next let the students play with the different pitches of sounds by tapping their pencils on the sides of the cans.  This will create different pitches and they should therefore start figuring out which ones are higher and which ones are lower.

6)      Lastly, have the students arrange their cans from highest to lowest pitches.  You could even ask each table to come up with a little tune, and award prizes for the best sounding song.

Explanation:

• Sound is produced by the vibrating can, and the amount of liquid in each can affects the rate of vibration
• The cans with more liquid vibrate slower, which produces lower-pitched sounds.
• The cans with less liquid vibrate faster, which produces high-pitched sounds.

Mixing Colors

Mancilla

Materials: pencil

scissors

white cardboard or heavy white paper

crayons or markers

ruler

a small bowl or a large cup (3 - 4 inch, or 7 - 10 cm diameter rim)

a paper cup

Procedure:

1. Use the bowl to trace a circle onto a piece of white cardboard and cut it out. With the ruler, divide it into six approximately equal sections.

2. Color the six sections with the colors of the spectrum as shown. Try to color as smoothly and evenly as possible.

Green, blue, purple, red, orange, yellow

3. Poke a hole through the middle of the circle and push the pencil part of the way through.

4. Poke a hole in the bottom of the paper cup, a little bit larger than the diameter of the pencil. Turn the cup upside down on a piece of paper, and put the pencil through so the point rests on the paper on a table. Adjust the color wheel's position on the pencil so that it is about 1/2 inch (1 - 2 cm) above the cup.

5. Spin the pencil quickly and observe the color wheel. Adjust as necessary so that the pencil and wheel spin easily.

Conclusion:

The colors on the wheel are the main colors in white light. When the wheel spins fast enough, the colors all appear to blend together, and the wheel looks white. Try experimenting with different color combinations.

ON THE REBOUND
Lauren Vosburg

Topic
Patterns (height of drop/ball's bounce)
Key Question
How does the ball's bounce compare with the height of the drop?
Focus
*Students will discover a pattern relating the height from which a ball is dropped to the height of its bounce.
*Mathematics is the study of many kinds of patterns, including numbers and shapes and operations on them.
*Sometimes patterns are studied because they help to explain how the world works or how to solve practical problems, sometimes because they are interesting in themselves.
*Measurements are always likely to give slightly different numbers, even if what is being measured stays the same.
*Graphical display of numbers may make it possible to spot patterns that are not otherwise obvious, such as comparative size and trends.

Materials for each group:
Plastic golf ball
Normal golf ball
meter stick
small pieces of paper
Graph paper

Background Information
Students intuitively know that the ball will drop to the ground. The force of gravity is pulling the ball toward the Earth. Students also intuitively know that the higher the drop, the higher the bounce; the lower the drop, the lower the bounce. The attention here is on the pattern formed from the data.  We want students to get excited about finding patterns. There is a relationship, a pattern between the height of the drop and the height of the bounce for a particular ball striking a particular surface. With the kind of data being gathered, a line graph is often used to show the results. However, a bar graph is more under­standable for younger students. If they compare the differences in bounce heights on a bar graph, students should find they form fairly consistent increments. They can then use this incremental distance to predict the bounce height for a drop from 120 centimeters.
Measurement is never exact. A measurement can always be taken to another, more precise decimal place. Measuring a ball in motion is even more difficult. Students should realize that their measurements are approximate.

Instructions
1. Divide the class into groups of two.
2. To test the bounce, hold the meter stick vertically or tape it to a wall or pole. Hold the ball so its bottom is even with the designated height and let it drop; do not throw or push. By standardizing the way the ball is handled, a variable is being controlled.
3. To measure the bounce, find the distance from the surface to the bottom of the ball at the height of its bounce.
4. Use a concrete surface if possible.
5. Although the graph starts with zero and rises to 100, more accurate measurements are likely if students conduct the tests in reverse order, starting with the 100-centimeter drop.
6. Students should conduct several trials at each height because it requires practice to read a measurement when an object is in motion. When they are getting fairly consistent readings, they are ready to record the result. Students should read the
measurement at eye level.
7. The students should get data for  20cm , 40cm, 60cm, 80cm and 100cm.  Once they have found all the measurements they are to make a graph and see if they can find a conclusion to the ball bouncing.

Discussion
1. What did you observe when you first dropped the balls (before doing the investigation)? [They fall to the ground (gravity).  They bounce back up, but not as high. The higher you start, the higher the bounce.
2. What does the bar graph tell us?
3. How do your group's results compare with others? (Variations in the accuracy of measurements and how well variables are controlled can cause differences.)
4. How can we make a height-of-bounce prediction for a 120-centimeter drop height? (Have students look for patterns in the bar graph.)

# Bending Water

## Materials

Water Faucet

Balloon

### Grade Level: 1st and 2nd

Static Electricity activity

### Purpose

Students should understand that static electricity is the accumulation of an electrical charge.  This charge is produced when two objects are rubbed against one another.  In this particular activity the charge of the balloon attracts the molecules of water in the stream, and because the molecules in the stream can be moved easily, the stream bends toward the balloon.

Steps:

First the students should blow up the balloon and tie it.

The, they should adjust the water faucet to produce a small stream of water to about 1.5 millimeters in diameter.

The students should then rub the balloon several times on their hair to charge the balloon.  After the balloon is charged they should then bring it near the stream to about an inch or less.  The balloon should bend towards the balloon.

To add more to the activity the students can also try different things for example they can bring the balloon even closer, maybe increase the stream of water, or charge the balloon a little more.

Sara Pernillo Vargas

Good Vibrations

Objective: To provide a concrete model for showing how sound vibrations travel from a sound maker to our ears.  Students will discover that in order for there to be a sound there must be a 1) vibrating source {the coat hanger}, 2) a material through which the sound vibrations travel {the string}, 3) a sound receiver {our ears}.

Materials:              metal coat hanger

2 pieces of string (about 50 cm long) – yarn, fishing wire, or tooth floss.

pencil -- optional ( keys or metal spoons)

Procedure:             1. Tie a piece of string to each end of the bottom of the coat hanger.

2. Wrap the other ends of the string a couple of times around your index fingers.

4.  Have your partner use a pencil to lightly tap the hanger.

(Describe the sound).

Conclusion:  Once the sound reaches your ear, it makes your ear drum and other parts of your ear vibrate.  The vibrations cause nerve messages to go to your brain.  Your brain interprets these messages as sounds.

There must always be some material for a sound to travel through to get to your ear.  Here the material is the string and your finger.  Usually the material is the air.  When the sound travels through air, it makes particles of the air vibrate, but they are too small for you to see of feel.

##### Robin Drascich

Time:  5-10 min.

Materials:  1 candle

Matches

1 Crayon & Sharpener

Bucket of water or sink nearby

Procedure:  1. Light the candle.  Ask the class what will happen when you hold a business card directly over the flame.

2. Hold a business card directly over the flame.  (It should catch on fire within a few seconds)

3. Place a pile of crayon shavings on top of the second business card.  Ask the class what will happen when you hold this business card directly over the flame.

4. Hold the business card directly over the flame so that the shavings are just above the flame.  (The shavings should melt in a short time, but the business card won’t even be burned)

Conclusion:  In order for paper to burn, it must reach a temperature of 451 degrees Fahrenheit.  Crayon melts at a lower temperature than paper.  In the demonstration, heat is transferred from the candle to the paper, and from the paper to the crayon.  As the crayon melts, it absorbs heat from the paper just as fast as the paper absorbs heat from the candle.  The business card never absorbed enough heat to reach 451 degrees so it does not burn.  Cool!

Colliding Coins

###### April Shelton

Materials:

Stack of 10 to 15 identical coins

What to do:

1. Make a stack of 5 coins.
2. Place another coin on the table close to the stack.
3. Use your finger to flick the coin at the bottom of the stack. (You may have to try a couple of time.)
4. Watch what happens to the bottom coin of the stack when the flicked coin hits it.
5. Add more coins to the stack and see how high you can get it before it falls down (..if it falls down)

What is happening?

The science behind this is the Law of Inertia which states that an object at rest will stay at rest---in other words, the object won’t move if it’s not moving already.  The stack of coins was at rest.  The flicked coin was full of energy.  The energy of the flicked coin was transferred to the stack and the bottom penny began to move.

CAN THE PRESSURE

Lauren Perigan

Materials (per experiment):

Ÿ         Glass canning jar with tight lid (have an adult poke a hole in the lid just large enough for a straw)

Ÿ         A fairly sturdy drinking straw

Ÿ         1-2 cubic centimeters of modeling clay

Ÿ         1-2 large marshmallows (not stale)

Ÿ         ½ cup to 1 cup drinking water

Ÿ         A plastic baggie

Ÿ         A rubber band

Ÿ         A paper towel

Make sure there is an understanding of and review terms like force, pressure, atmosphere, atmospheric/air pressure, low and high pressure. Discuss how air has weight and that it pushes on everything to create a force. Show what force does to a marshmallow by pressing it between your hands, then explain that air can do this as well.

Ÿ         Have the students prepare their airtight jars by inserting the straw in the lid and securing the straw with the modeling clay on both sides of the lid, so that no air can pass through the lid except through the straw.

Ÿ         Next, the students should put their marshmallow(s) in the jar and secure the lid tightly on the jar.

Ÿ         Ask: Is the pressure in the jar higher, lower, or the same as outside the jar right now? How can we put more air pressure in the jar? What will that do to the marshmallow?

Ÿ         Let the students test their hypothesis, and ask them what will happen with low pressure and test their guesses again.

Now explain what air pressure has to do with drinking through a straw. When you drink from an open glass of water, air pressure allows the water to travel up the straw.

Ÿ         Have the students replace the marshmallow(s) with drinking water so that the straw is in the water when they seal the jar back up.

Ÿ         Have the students try to suck the water up. They may be able to suck up some, but not much and it is very difficult.

Ÿ         Discuss: By sucking on the straw you are reducing the air pressure inside your mouth. While sucking on the straw, the air pressure in your mouth is less than the air pressure outside of the straw (in the room, in the glass, etc.). The outside air pressure is pushing down on the water which forces the water up the straw. But when air pressure on the water is blocked (when you seal the jar lid), there is no air pressure to help push the water up your straw. The air can’t get to the water to push on it, so it doesn't go up the straw.

Ÿ         Finally, have the students pour out the water in the jar and dry it with the paper towel.

Ÿ         Have the students open the plastic baggie inside the jar and fold the opening of the baggie over the mouth of the jar. Try to have the least amount of air as possible between the baggie and the inside of the jar. Secure the rubber band around the mouth of the jar tightly, so that no air can escape or enter the jar.

Ÿ         Ask the students to try to pull the baggie up from inside the jar, outside.

Ÿ         Let the students try to explain why.

The pressure inside and outside the jar is the same. When attempting to pull the baggie out, you are keeping the same pressure inside the jar because it is airtight, but you are trying to increase the volume which makes the air have to spread out; thus reducing the pressure. Now there is greater pressure outside the jar pushing on the baggie, and keeping it in the jar.

*If time allows or more explanation of pressure is needed, discuss how air pressure affects our bodies. Explain how pressure is different at different altitudes and how we need to “crack our ears” when we go to the mountains, and why our ears hurt when we dive to the bottom of the swimming pool. (If air has so much pressure, and it weighs so little, imagine what heavy water can do!)

SCI 210 Lab Presentation:  2- point discrimination test

Purpose:

For students to be able to answer this question:  What areas of their bodies are the most sensitive to touch?  To explore the difference in the degree of sensitivity the skin holds on different body parts.  (ie.  Hands, feet, thigh, forearm, etc.)

Materials:

Toothpicks

Procedure:

To find out what areas of the skin are more sensitive have the students perform a 2-point discrimination exam of a friend.  Give each pair to student’s two toothpicks.  Make sure the tips of the toothpicks are not too sharp!  If so, press the points against a hard surface to create a more blunt end on the pick.

Have the pairs of students begin taking turns testing different areas on each other.

The Test:

While one student is performing the test, the other student should be closing their eyes so they cannot see where the toothpicks are.  Make sure the students do not press too hard!  The student performing the test on a body part will begin by touching the toothpick tips on the skin several inches apart and slowly work the picks closer together.  Make sure both tips touch the skin at the same time while moving them together.  Have the student ask their partner if he or she felt 1 or 2 pressure points every time the picks move.  If the student reported 1 point, spread the tips of the pick a bit further apart, and touch the previous point again.  If the student reports 2 points have their partner open their eyes and see where their 2-point discrimination is on that body part.  Then have the students measure the distance at which the subject reports, “I feel 2 points”.  They will do this for all the body parts tested.  After one student has performed the test, have the students switch roles.

Testing Areas:             1 pressure point (cm)     2 pressure points (cm)

 Finger Lip Cheek Nose Palm Forehead Foot Belly Forearm Upper arm Back Shoulder Thigh Calf

Critical Thinking:

When the activity is finished you can have the students look at their data and determine what parts of the body are most sensitive.  In other words, where on the body can 2 points be detected with the smallest tip separation?  The students will discover that the receptors in our skin are not distributed evenly on our bodies.  Some places, like our fingers and lips, have more touch receptors than other parts.

##### The Exploding Lunch Bag!
###### Erin Tu

Materials:

·        One small zip-lock bag - small freezer bags work best.

·        Baking soda

·        Warm water

·        Vinegar

·        Measuring cup

·        A tissue

Procedure:

1. Go outside - or at least do this in the kitchen sink.
2. Put 1/4 cup of pretty warm water into the bag.
3. Add 1/2 cup of vinegar to the water in the bag.
3. Put 3 teaspoons of baking soda into the middle of the tissue
4. Wrap the baking soda up in the tissue by folding the tissue around it.
5. You will have to work fast now - partially zip the bag closed but leave enough space to add the baking soda packet. Put the tissue with the baking soda into the bag and quickly zip the bag completely closed.
6. Put the bag in the sink or down on the ground (outside) and step back. The bag will start to expand, and expand, and if all goes well...POP!

What happens inside the bag is actually pretty interesting - the baking soda and the vinegar eventually mix (the tissue buys you some time to zip the bag shut).  When they do mix, you create an ACID-BASE reaction.  The two chemicals work together to create a gas, (carbon dioxide - the stuff we breathe out).  Well it turns out gasses need a lot of room and the carbon dioxide starts to fill the bag, and keeps filling the bag until the bag can no longer hold it any more and, POP!

Susan Flanagan

Make a Magnet Float in the Air

Materials:

2 round magnets

pencil

washers

Procedure:

1.      Place 1 magnet of table.

2.      Put lead point of pencil in center hole of magnet.

3.      Slide other magnet down pencil.

4.      Did 2nd magnet float in air?

5.      Try again; take top magnet off, flip over and slide down pencil.

Observation:

One side of magnet will float in the air.  The other side affixes to the bottom magnet.

Questions:

Why does one side float and the other side doesn’t?

Explanation:

A magnet consists of two different ends or sides called poles.  It has a north pole and a south pole.  When like poles are brought near each other they repel or push each other away, but when opposite poles are brought together they attract each other or stick together.  The area between the repelling magnets is the magnetic field.  It is an invisible force that surrounds a magnet.

2nd Procedure:

1.  Measure area between the magnets.

2.      Place washers on top of floating magnet.

3.      How many does it take to counteract the magnetic force?

What would happen if you tried to float the magnet without the pencil?

Magnetism: The Floating Paper Clip

By Crystal Carter

Problem:

Can a paper clip float in the air?

Research:

Magnetism is a force that attracts iron, nickel and cobalt. Combinations of these metals as alloys can become permanent sources of magnetism. They are called magnets. It also both attracts and repels other magnets. The force that attracts and repels two magnets is a force that acts at a distance called magnetism or magnetic force. There are a few rare-earth materials such as bismuth that are actually repelled by a magnet. The force is very weak, but it is interesting that it is opposite of iron. The opposite ends of a magnet are called its north and south poles. In reality, they should be called the "north seeking" and "south seeking" poles, because they seek the Earth's North Pole and South Pole, respectively.

Materials:

·        One paper clip

·        One magnet

·        A piece of fishing string

·        A piece of tape

Procedure:

1) Tie the fishing string or line to the paper clip.

2) Tape the other end of the string to the table.

3) Hold the magnet just above the paper clip so it appears to float at the end of the thread.

Conclusion:

By doing this experiment, the child can see that science can be fun and not even look like an experiment, but a magic trick. You could let the student experiment with other magnets that are bigger or stronger and see which one makes the paper clip float more freely through the air. You can have them see if they attract or repel each other. The students will learn about magnetism and how each time you cut the magnet, two poles form on each new magnet. You could also put beads on the paper clip and let the children experiment with the strength of the magnet, depending on how much weight can be picked up by the magnet.

Norma Franco

Shock Them All

Concepts Taught: How a Battery Works.

Materials:

• Lemon Juice
•  9 1' X 1' strips of paper towels,
• 5 pennies, 5 dimes
• Cup

Experiment

Experiment first dome by the Italian physicist Allessandra Volta 200 years ago.

Instruction:

·        Soak the paper towel strips in the lemon juice.

·        Make a pile of coins, alternating dimes
and pennies. Separate each one with a lemon-soaked strip of paper towel.

·        Moisten one finger tip on each hand and hold the pile between your fingers.

Questions:

What did you feel?

What is the function of the lemon juice?

If you place the lemon soaked strips at the top and bottom of a stack of one penny and one dime would you have the same reaction? Why?

Closure: You have mad a wet cell, the forerunner of the battery we buy at the store. The lemon juice, an acid solution, conducts the electricity created by the separated metals of the coins. What we call a battery is actually two or dry cells. In each dry cell, 2 metals (a zinc metal container and a carbon rod) are separated by blotting paper soaked in a strong acid.

Krista Lane

# Fabulous Flashlights

Purpose:  In this activity students will use a flashlight to learn more about electric circuits and discover different kinds of materials through which electricity can travel.

Materials Needed:  standard 2-battery flashlight, blunt-end scissors, pencil, quarter, nickel, and penny, paper, aluminum foil, and plastic wrap.

Activity:

1. Have you ever looked inside a flashlight to figure out how it actually works?  Now look inside and see whether you can figure out the complete circuit through which the electricity flows to make the bulb light.  How do you think the switch works?
2. The electric circuit in your flashlight includes two batteries.  Look at one of the batteries.  It has a bump on one end, and the other end is flat.  These are the terminals of the battery.  Look carefully and you should find that one terminal is marked positive (+) and the other is marked negative (-).  What kind of terminal is the end of the battery with the bump?
3. Do you think it matters how the two batteries are arranged in your flashlight? Try arranging the batteries in different ways and see whether the flashlight will still work.
4. What do you think will happen if you put the two batteries in the flashlight the correct way, but you put a quarter between them?  Do you think the bulb will still light when the flashlight is turned on?  Try it and see! Was the electricity able to travel through the quarter? What about a penny or a nickel?
5. Then after using the quarter cut circles the size of a quarter out of paper, aluminum foil, and plastic wrap.  What happens when you place each of these between the batteries in our flashlight?
6. Separate all the materials you tested into conductors and insulators.  Was the bulb brighter with some conductors than with others?

Explanation:  Have students separate the materials they tested into conductors and insulators.  A conductor is a material that is usually metal through which electric charge can flow.  An insulator is a material that is a poor conductor of electricity.  After the students separate the materials ask them if the bulb was brighter with some conductors than with others?

Source:  Wonder Science Book Volume I.

Javier Gudino

How to Make a Rainbow

Experiment # 2

Suggested time: 15 minutes

Objective:

• Find out how to break white light into different colors, thus forming a rainbow.

Definition:

• Refraction—The bending of light when it moves from one kind of matter to another.

Predictions:

• Will light bend through a glass of water?

Materials:

• Small mirror
• Clear glass
• Flashlight
• Water

Procedure:

1. Gently place the mirror into the glass.  Slant it up against the side.
2. Fill the glass with water.
3. Set the glass on a table.  Turn off the lights.  Make the room as dark as possible.
4. Shine the flashlight into the glass of water.  Aim for the mirror.  Adjust your aim until the light hits the mirror.  If necessary, adjust the mirror in the water.  Make sure the mirror is slanted.
5. Observe what happens to the light in the glass.  Look at the light where it hits the ceiling or the wall.  What do you observe?

Conclusions:

1. What did the light look like as it went into the glass?  The light looked white as it went into the glass.
2. What did the light look like after it came out of the glass?  The light came out of the glass and made a rainbow on the wall or ceiling.
3. How was the rainbow formed?  When the white light from the flashlight moved from the air to the glass of water, the different colors of light contained in the white light bent (refracted) at different angles.  The bending separates the light into its colors, and you see a rainbow.  When white light separates, its colors always appear in the same order.  The order is red, orange, yellow, green, blue, and violet.

The Reappearing Coin

Purpose:

To demonstrate that light refracts.

Materials: Non-transparent Bowl         Straw

Coin                                    Water

Transparent Cup

Engage:

• Tell students that they will be doing a "reappearing coin act."
• Divide students into small groups. Provide each group with a bowl, a coin, and a glass of water.
• Have students place the empty bowl on a table or desk and place the coin inside the bowl. The coin should sit as close to the edge as possible.
• In each group, have one student (student A) look at the coin while slowly moving backwards until he or she cannot see the coin. Tell this student not to move.
• Have another student (student B) in each group gently pour water into the bowl. Students A should be able to see the coin even though they have not changed their positions.

Exploration:

• In this experiment, tell each group to fill their glass halfway with water.
• Give each group a few straws.
• Tell students to place the straws in the water. The water should cover half of the length of the straws.
• Tell students to look at the straws from the side of the glass.
• Have them make observations about the appearance of objects.

Explanation:

• Engage students in a discussion about their observations. All students should observe that their objects appeared bent even though the object was straight. Ask students what happened in this experiment.
• Explain to students that light travels at different speeds when it hits different matter. Light travels slower in water than in air. So, when light rays strike water, the light slows down and changes direction. It makes objects look bent. When light changes direction, it is called refraction.
• Have students predict and explain what happened in the "reappearing coin act."

Juli Ann Garduque

The Fireproof Balloon

Grade level= 4th or 5th  (Because of the use of matches)

Objective= To explain how water is a good absorber of heat.

Materials:

●Two round balloons, not inflated

●Matches

●Water

Procedure:

1.      Inflate one of the balloons and tie it close.

2.      Place 60 milliliters (¼ cup) of water in the other balloon and then inflate it and tie it shut.

3.      Light a match and hold it under the first balloon.  (The balloon without water in it)

4.      Allow the flame to touch the balloon.  What happens?  The balloon breaks, perhaps even before the flame touches it.

5.      Light another match.  Hold it directly under the water in the second balloon.

6.      Allow the flame to touch the balloon.  What happens with this balloon? The balloon does not break.

7.      You may even see a black patch of soot form on the outside of the balloon above the flame.

Conclusion:

Why didn’t the balloon with no water break in the flame?  The flame heated whatever was placed over it.  It heated the rubber of both balloons.  The rubber of the balloon without water became so hot, that it was too weak to resist the pressure of the air inside the balloon.

How did the balloon with water in it resist breaking in the flame?  When water inside the balloon was placed over the flame, the water absorbed most of the heat.  This caused the rubber of the balloon to not become very hot.  Because the rubber did not become too hot, it did not weaken, and the balloon didn’t break.

Discussion:

Water is a particularly good absorber of heat.  It takes a lot of heat to change the temperature of water.  It takes ten times as much heat to raise the temperature of 1 gram of water by 1C than it does to raise the temperature of 1 gram of iron by the same amount.  This is why it takes so long to bring a teakettle of water to the boil.  On the other hand, when water cools, it releases a great deal of heat.  This is why areas near oceans or other large bodies of water do not get as cold in winter as areas at the same latitude further inland.

http://scifun.chem.wisc.edu/HOMEEXPTS/FIREBALLOON.html

`Erin Lloyd`
`Moving Molecules`
` `
`TITLE:    MOLECULES and TEMPERATURE`
`GRADE LEVEL: Appropriate for Primary Grades`
`OVERVIEW and PURPOSE:  The study of molecular concepts, especially their movement and relationship to temperature, is difficult for primary children to grasp.  Through language arts, science experiment and movement activity, students will gain an understanding of temperature and molecular movement.`
`OBJECTIVES:  Students will be able to:`
`1.  Explain that molecules are in everything living and nonliving.`
`2.  Explain that molecules are too small to see but we can watch their     movement.`
`3.  Demonstrate molecular movement in hot and cold water and explain temperature rise and fall depending on molecular movement.`
`4.  Through oral and written expression demonstrate an understanding of the following vocabulary words:`
`Temperature, molecule, movement, molecular movement, particle, rise and fall.`
`5.  Through movement activity, demonstrate molecular movement as pertaining to rising and falling temperature.`
`RESOURCES/MATERIALS NEEDED:`
`Hot as an Ice Cube by Philip Balestrino`
`Two clear cups/bowls and food coloring`
`ACTIVITIES AND PROCEDURES:`
`A.  Read Hot as an Ice Cube by Philip Balestrino`
`    Concepts to develop:`
`    1.  Temperature is a measure of how hot or cold something is.`
`    2.  Adjectives to describe temperature such as hot, cold, warm, lukewarm, chilly, sizzling and freezing.`
`    3.  Heating something makes its temperature. As it cools off its temperature falls.`
`    4.  Everything is made of tiny particles call molecules.`
`    5.  Molecules are always moving.`
`    6.  The faster the molecules in something move, the hotter it is.  The more you heat something, the faster the molecules move.  This is what cause its temperature to rise.`
`B.  Experiment- To see that molecules of water move faster when the water is hot.`
`    1.  Put water in two clear cups/bowls (one hot, one cold).`
`    2.  Allow the water to sit for a moment to stop movement.`
`    3.  Carefully put a drop of food coloring into the middle of each cup.`
`    4.  Observe the molecules move the food coloring around (rapidly in hot water, slowly in cold water).`
`TYING IT ALL TOGETHER:`
`Extension Activity:  Small groups of children act out being molecules.  They start out as frozen water (clustered very still as frozen water molecules).`
`Pretend the temperature is gradually rising until it reaches boiling (children move around rapidly) and then let the temperature fall again.`

Conduction Countdown!

# Debbie Lau

Objective: Observe what happens when heat is transferred from one object to another.

Materials:

· two slices of cold butter

· a metal knife

· a plastic knife

· a glass of warm water

Procedure:

· Poke each knife into a slice of butter.

· Put the handles of the knives into the glass of warm water.  Make sure that the

butter slices are sticking up in the air.

· Watch to see which butter slice melts first.

Discussion: This experiment demonstrates heat conduction.  First, the warm water will

transfer some of its heat to the knife handles.  The handles will then transfer their energy to the blades, which will eventually melt the butter.  However, some materials conduct heat better than others do.  For example, metals allow electrons to flow freely, making them good conductors.  On the other hand, plastics do not allow electrons to flow as freely, making them nonconductors.  Nonconductors are also referred to as insulators.

Gabriela Montoya
Frightened Run-Away Pepper
H H
\ /
O
Introduction:
As children begin to experiment and manipulate different materials I feel it is important for them to experiment with water. Water is essential for our survival and children should be more aware of its properties. First begin by explaining that water has a surface tension. Surface tension refers to the layer of water molecules on the waters surface which acts as a strong but flexible film or skin. Since the water molecules on the surface are pulled mainly down and in by the water Molecules below them, they form a tighter, more uniform surface tension layer on top of the water.
Water molecules are composed of two atoms of hydrogen and one atom of oxygen. You can even have children make a water compound by using tooth picks and jelly beans. And last one would explain that cohesion is the force that holds materials together. For example, glue or tape have cohesion.

You Will Need:
black pepper
8-oz. cup or small bowl
liquid dish detergent
eye dropper

Instructions:
Fill the 8 oz. cup a third of the way full. Add black pepper over the top of the water so that a thin layer of pepper forms. Open the liquid dish detergent and get a drop of detergent with the eye dropper and then add it to the cup. Talk about observations with the class.

Expected Outcome:
Once the drop of liquid detergent meets the water, and the layer of pepper, the pepper quickly moves away from the detergent. The pepper is evenly pulled by the water form all directions. The detergent reduced the cohesiveness between the water and the pepper. However, the pepper that is around the rim of the cup is still pulling together as a result of the detergent not reaching it.
One can also draw on the board a cup that is filled with water and explain that by being able to see this through a microscope one would be able to see the surface tension layer. If one were to put a tooth pick on the surface tension of the water it would result in a star like layer because of the tooth pick breaking the surface tension.
This experiment will help children become aware of the fact that water has many properties and as a result come to value water.

_____________________________________________________________________________

Gabriela Montoya
Go with the Flow
The Force of Friction

Introduction:
Question: What is Friction?
Answer: When surfaces slide or tend to slide over one another.
There are two kinds of frictions: 1)Static Friction, which is a resistance to the beginning of motion. It happens when tow objects touch and are at rest.
2)Moving Friction which is a resistance to motion that already exist. Static friction is greater that Sliding Friction.

Friction is a force that affects our lives all the time. It slows us down when we swim or run. Without it we couldn't¡¦t move at all. Friction affects objects that rub against other objects. It also affects objects that move through liquids and gasses. We will be investigating how size and shape affect the friction on an object moving through fluids. You Will Need:
„X Play Doh
„X 8-oz. see through cup
„X water

Instructions:
Fill the 8 oz. cup until it is almost full. Then roll the clay into two little balls. You are going to have a friction face with your partner. You will drop one ball just as it is and the other ball you will flatten into a pancake. Then you hold both pieces of clay close to the surface of the water. Drop both of them at the same time.
„X What did you observe?
„X Do you think friction had anything to do with the difference speed of the clay?
„X Why do you think speed boats and fish have such smooth shapes? Expected Outcome:

The Play Doh pancake will fall much more slowly in water than the Play Doh ball. There are two reasons for this difference.
1) Since friction happens at the surface of an object, the larger the surface area, the more friction. A flattening makes the surface area even larger. This larger surface increases the friction.
2) The pancake usually stay horizontal as it fall, it must push the water under it out of the way as it moves. This slows down the pancake even more.
This experiment will help children become aware of friction and how it affects them on a daily basis.

Jeneen Stubblefield

Color Run

Purpose: To make food coloring run around the bowl of water with soap as its power source.

Materials:  Bowl or pan (thin pie pans work really well)

Toothpicks

Liquid detergent

Food Coloring

Milk (2% works best)

Measuring Cup (1cup measures)

Begin with a discussion on molecules.  Explain that the surface of the milk is held together by tiny molecules.  What would happen if we put a substance in the middle of the milk?  What happens to the molecules in that area?  This experiment demonstrates this.

Measure one cup of milk and pour into the pie pan.  Put in three to four drops of the food coloring in the milk.  Using different colors heightens the experiment.  Dip the pointed tip of the toothpick in the liquid detergent.  Place the pointed tip of the toothpick in the drops of food coloring.  Watch what happens.  If the reaction stops you may dip the toothpick in the liquid detergent again.

Why do the colors run from the toothpick?  The liquid detergent weakens the bonds of the milk molecules in that area.  The stronger molecules away from the detergent pull the colors across the surface of the milk toward the side of the pan.

The activity can be repeated until all of the colors are mixed

Super Sparker

Making very, very tiny lightning!!!

Diana Ramirez

Materials:

• Scissors
• Styrofoam plates
• Aluminum pie tin

What to do:

1.       Cut a semi long rectangular piece off one of the Styrofoam plates.  You’ll have a long piece and should try to make a triangular handle out of it.

2.       Tape the bent piece made into a triangle to the center of the pie tin.  Now you have a handle.

3.       Rub the bottom of the Styrofoam plate on your hair. Rub it all over, really fast.

4.       Put the tray upside down on a table or on the floor.

5.       Use the handle to pick up the pie tin.  Hold it about a foot over the Styrofoam plate and drop it.

6.       Now, very slowly, touch the tip of your finger to the pie tin.  Wow! What a spark!  (Be careful.  Don’t touch the Styrofoam plate.  If you do, you won’t get a spark.)

7.       Use the handle to pick up the pie tin again.  Touch the tin with the tip of your finger.  Wow?  You get another great spark.

8.       Drop the pie tin onto the Styrofoam plate again.  Touch the pie tin.  Another spark!  Use the handle to pick up the pie tin.  More sparks!

9.       You can do this over and over for a long time.  If the pie tin stops giving you a spark, just rub the Styrofoam plate on your head again, and start over.

Sparks In The Dark

Try using your Super Sparker in the dark.  Can you see the tiny lightning bolts you make?  What color are they?

What’s going on?

When you rub Styrofoam on your hair, you pull electrons off your hair and pile them up on the Styrofoam.  When you put an aluminum pie tin on the Styrofoam, the electrons in metals are free electrons, they can move around inside the metal.  These free electrons try to move as far away from the Styrofoam as they can.  When you touch the pie tin, those free electrons leap to your hand, making a spark.

After the electrons jump to your hand, the pie tin is short some electrons.  When you lift the pie tin away from the Styrofoam plate, you’ve got a pie tin that attracts any and all nearby electrons.  If you hold your finger close to the metal, electrons jump from your finger back to the pie tin, making another spark.  When you put the pie tin back on the Styrofoam plate, you start the whole process over again.

What does all this have to do with lightning?

The lightning bolt is a dramatic example of static electricity in action.  You see lightning when a spark of moving electrons races up or down between a cloud and the ground (or between two clouds).  The moving electrons bump into air molecules along the way, heating them to a temperature five times hotter than the surface of the sun.  This hot air expands as a supersonic shock wave, which you hear as thunder.

Roberta Caloca

Cereal Slurry

Intro:  The iron in high iron cereals can be separated from cereal by using a magnet.

Material:  measuring cup, water, blender, high iron cereal (Total), clear plastic cup, strong magnet, plastic spoons, one other kind of cereal.

What to do:

1. Pour 1 ½ cups of water into a blender.  Add 1 c dry high-iron cereal & blend at high speed for 30 seconds.  Until it’s a smooth slurry.
2. fill a plastic cup (3/4 full), of slurry
3. place a strong magnet against the other side of the cup ½ way up from bottom.
4. While holding the magnet against the cup, stir slurry with plastic spoon for 30 seconds.
5. Pull magnet away from the cup & look at spot where the magnet was touching.
6. Move magnet around while holding it against the cup.
7. Repeat step 1-5 for other cereal.  Note which one attracts most particles.

What Happening:  Many-iron rich cereals contain iron in a powdered form that is baked into the cereal.  When you blend it with water, the iron separates.  When the magnet is held against the cup, the magnet force goes through the plastic & attracts iron powder.  You can make iron powder follow magnet.

Connection:  It is interesting that the same metal used for automobiles, hammers, bikes, is used in powder form in cereal.

Observation:

What happened?  Which cereal attracted more particles?  What happened when magnet was removed?  What happened when magnet was moved around the cup?

What it means:  Look at the ingredients.  What items listed to you think were attracted to the magnet?

### Hanh Nguyen

“Solid or Liquid?”

Purpose:  To obtain the knowledge and understanding of the states of matter and its properties and also differentiate them from each other through observations.

Materials:  Tapioca Starch/Corn Starch, Water, Cups, Food Color, and Zip Loc Baggies

Preparation:  Prepare zip loc Baggies by putting one to two teaspoon of tapioca or cornstarch into each bag.  Get three different cups and fill it up with water and add yellow food color to one cup, blue food color to another cup, and red food color to the third cup.  Mix the food color with the water well.  Do some research on state of matter and its properties to present information to students.

Procedure:  Teacher briefly discusses the state of matter and its properties with the students.

1. Hand each student a baggie that has some starch in it.  Ask the students if it is a solid or liquid and how do they know this.
2. Students can choose what color or combination of colors they want to put into their baggie.  Add two to three tablespoon of the prepared solution to the baggie.
3. Zip it up and begin to squeeze it so that the two will mix.  Ask the students what type of mater did they just add to their baggie and what do they predict will happen.
4. Take the substance out of the baggie and play with it, make shapes out of it.  Now ask the students what state of matter is it in.
5. Then place the substance on your hand and do not move your fingers.  What do they see/observe?  What state of matter is it now?
6. Teacher explains why the state of matter varies.  Also remind the students not to eat the substance because it is dirty as they through it around and put germs on it.

Conclusion:  The state of matter may vary as the variable s varies.  Changes in temperature and chemical reactions will affect the state of matter.  This activity is easy and fun to do with students, especially in the lower grades where they are able to explore and experience simple concepts of science.

Alicia Rivera

Raisin’ Raisins!

Carbon Dioxide

Wonder Science Book

Purpose: To teach children about carbon dioxide

Objective: Help children understand the concept of carbon dioxide and how it interrelates with buoyancy.

Materials:

Raisins

Clear soda

Clear plastic cups

Instructions:

• Place 3 raisins in the soda in each cup and observe closely. After sinking to the bottom, the raisins should soon get bubbles on them lifting them up to the surface. Some of the bubbles should break, causing the raising to sink.
• Observe your raisins for a minute or two.  Each of you should choose the raisin that floated to the top of you cup most often.  This is your prize raisin!
• Remove the raisins from the cups and save your prize raisin.  Put one cup away and place the other cup in the middle as the Raisin Challenge Cup!  After yelling “GO” partners should place their raisins in the challenge cup. The raisin that gets to the surface the most times in 2 minutes wins!

What qualities does your prize raisin have that you think made it go up and down better than others?

Do you think there is anything you could do to your raisin or a new raisin that would improve its chances for victory?

Conclusion:

Children need to understand that Buoyancy arises from the fact that fluid pressure increases with depth and from the fact that the increased pressure is exerted in all directions so that there is an unbalanced upward force on the bottom of a submerged object.

Carbon dioxide, like everything else in the world is made up of atoms. You may know that two or more atoms can combine in a special way to make a molecule. Carbon dioxide is a molecule made up of one atom of carbon and two atoms of oxygen. That is why chemists use the letters and numbers CO2 to stand for carbon dioxide.  Carbon dioxide is one of the gases in our atmosphere that plants need to survive. When animals breathe, they taking oxygen and give off carbon dioxide. (Wonder Science Book)

Bending Water
By Wendy Mendoza

This is to show the students how neutral objects are attracted to charged objects.

Materials: A ballon
A sink and a water faucet

Procedures:
1. Turn on the faucet so that the water runs out in a small, steady stream.
2. Charge the balloon by rubbing it with a piece of wool or rubbing someone’s hair
3. Slowly bring the charged balloon near the running water and watch the water
“bend”.

What happened is that the neutral water was attracted to the charger comb, and moved towards it.

Go With The Flow

Terri Muniz

Objective:  Students will observe what happens when you mix food coloring and water to liquid hand soap.

Materials:

Water

Food Coloring

Clear Tape

Liquid Handsoap (With glycol stearate NOT glycol distearate)

Procedure:

1.  Fill the bottle about 1/4 full with liquid soap.  Add a few drops of food coloring.  This is so you could see the swirls better.

2.  Turn the faucet on and fill your bottle with water.  Make sure that the bottle is filled to the top.  Don't turn the faucet on too hard because this will cause you to get foam.

3.  Screw the cap on the bottle.  Turn the bottle upside down a few times to mix the soap and water.  If you shake the bottle to hard you might end up with foam.

4.  Wrap tape around the cap so it won't leak.

5.  Twirl the bottle slowly and see what happens.

6.  Look at all the different patterns you can see my twirling the bottle or shaking it.

Discussion:

If the water bottle was just filled with water you wouldn't be able to see in what direction the water is moving inside the bottle.  Water that's moving in one direction looks the same as water that's moving in another direction.  Adding the hand soap with glycol stearate let's you see patterns flow in water.

When you turn the bottle slowly you see smooth streaks and when you turn it fast you see lots of swirls and wavy patterns.  When water moves rapidly past anothe rlayer of water, it causes turbulence, which yuou see as swirly patterns.

When people design airplanes, cars, boats, and other objects that move through the air or water, they study the patterns air and water make as the object moves through it.  Differences in the flow of air or water affects how an airplane flies, how much mileage a car gets per gallon, and how fast a boat can go.

Lisa Costanza

## Dancing Quarter

Materials:

•glass bottle

•quarter

Instructions:

-wet the rim of the quarter as well as the rim of the glass bottle

-place the quarter on top of the opening of the bottle

-grip the bottle tightly with both hands

-wait a few minutes and then the quarter will begin dancing or lifting off of the bottle top

Conclusion:

This experiment is intended to show the effects of heating air.  Prior to this experiment the students should be informed of the issues regarding heating and cooling of air particles.  By placing your hands around the bottle you are heating up the air that is inside the bottle.  The students should be aware that when air is heated up it expands.  They will then understand that the heated air within the bottle is expanding or attempting to get out.  In its efforts to do so the quarter is being lifted up and down to let some of the expanding air out.  This experiment can work with a plastic bottle as well, but it will take longer to heat the air inside. The glass bottle works better because glass is a better conductor of heat.

Making a Buzzer

(Karla Camacho)

Objective:

To introduce students to one of many uses for electromagnets.

Materials:

• 1- 24 inch wood board about 2 inches wide and ½ inch think
• 1- metal coat hanger
• 1- nail
• 1- piece of sanding paper
• 2- washers
• 2- screws
• Thin coded copper coil
• 1- 9v battery

Procedure:

• You will want to try putting this experiment before hand and take note of its difficulty to make. Since this is for a ten minute presentation the students will require more than just ten minutes to make, along with other materials, such as screwdrivers and hammers
• Before giving the students time to observe the project let them know how electromagnets, current flow, and complete circuits work
• Let the students get into groups of three or four at the most so that they can discuss how the buzzer works
• Pose questions for the students such as, what is going on? How does it work? What do you notice?

• If the students were unable to figure out what made the buzzer work, then run with them the different items at hand
• Ask the students what they recognize individually from the buzzer some of them may mention the electromagnet
• Ask the students what the current flow is?
• Ask the students where the current flow breaks?
• If they still haven’t figured out how the buzzer works after these explanations then run it through with them. Letting them know that the screw with the coil creates a magnet causing the hanger to attract.  The current flow is broken when the hanger attracts to the electromagnet (screw with coil).  This happens back and forward continually causing it to give the buzzing effect.

Making a Compass

(Karla Camacho)

Objective:

To introduce students to North and South poles.

Materials:

• 1 Styrofoam bowl
• 1 cup of water
• 1 pin
• 1 strong north and south labeled magnet
• 1 cork or cut out piece of Styrofoam

Procedure:

• Provide groups of two with the material listed above.
• Have the students put the cup of water in the bowl
• Place the cork or piece of round styrofoam on the water in bowl
• Magnetize the pin by stroking the pin on the magnet from the middle towards the north side about 50 times.
• Make sure that the magnet is no where near the pin when it is placed on the styrofoam boat
• The side of the pin that was magnetized should now point south since the pairs of magnets where aligned south

• Ask the students what they notice
• Ask the students if they can explain what is happening
• If they cannot explain then tell the students how the pin is made up of small pairs of magnets not yet aligned until stroking on the magnet aligns them making them magnetic. This is possible because the pin is made of metal.
• Opposites repel and so the north side of the pin points south and the south points north
• As part of an extension to this activity you can have students experiment with other objects to see if they are magnetic or not. E.g. rubber bands, coins, foil, paperclips, paper etc.

## MAKE A BEGINNER'S TELESCOPE

`  ///`
`                                                 /`
`                       /\                        |`
`                      |  |                       |`
`                     |    |                /\  (( (`
`                     |    |               |  |   /\\`
`        .............|    |...............|  |...0 \\`
`                     |    |               |  |   \//`
`                     |    |                \/   /`
`                      |  |                     /`
`                       \/                     /`
`                                             (__== )`
`                                                 )`
`                                                (__`
`                                                   \`
`                                                 __/`
`                                                (`
`                                                 (`

A telescope with a tube is nice, but it's more complicated than necessary. A telescope with a sliding-tube focus is useful, but it's hard to build. A project that's too complex and difficult will drive people away, when the goal is to tempt them into building it.

Here is an extremely easy version of the classic Telescope build-it project. No tube or adjustable focus mechanism is required. All that you need is a pair of lenses. Tempting?

## THE LENSES

Two lenses are needed to build a telescope. We call these the "objective" lens and the "eyepiece" lens.

`                  /\`
`                 |  |`
`                |    |                /\  (( (`
`                |    |               |  |   /\\`
`   .............|    |...............|  |...0 \\`
`                |    |               |  |   \//`
`                |    |                \/   |`
`                 |  |                     /`
`                  \/`
`               OBJECTIVE           EYEPIECE`
`               LENS:               LENS:`
`               * large             * small`
`               * weak              * powerful`
`               * convex only       * convex OR concave`
` `
` `

The "Objective" lens should always be a convex lens. Convex lenses are thicker in the middle, and can be used as magnifying glasses or for concentrating sunlight. Try to find one which is large and weak. The weaker it is, the more powerful your telescope will be. The thinner it is in the center, the weaker it is.

` `
`    `
` `
` `
`      _______`
`   _--       --_`
`  <_           _>    Side view of convex lens`
`    --_______--`
` `
` `
`     ___----___`
`   _/          \_`
`  /______________\   This type of convex lens also will work`
` `

The "eyepiece" lens can be either a convex or concave lens. If you use a convex eyepiece, your telescope will turn everything upside-down. This kind of telescope is called a "Newtonian." And if you use a concave lens as your eyepiece, your telescope will not turn things upside-down. This type of scope is called a "Galilean."

For your eyepiece, try to find a lens which is small and powerful. A small, powerful magnifying loupe makes a good telescope eyepiece.

` `
`    |\_             _/|`
`    |  ----_____----  |`
`    |      _____      |   Powerful concave lens.`
`    | _----     ----_ |`
`    |/               \|`
` `
` `
`     _               _`
`    | ---_________--- |`
`    |    _________    |   Weak concave lens.`
`    |_---         ---_|`
` `
` `

Face a distant, well-lighted object such as a lamp, or distant trees outdoors. Hold your Eyepiece Lens right on your eye and look through it. It's OK to close your other eye. Hold your Objective lens right in front of your eyepiece. Slowly move your Objective lens forward until the scene comes into focus. Sometimes it's hard to find the right distance, so try many different places. Look through your lenses and find the blurry edge of trees or lightbulb, then move the objective lens in or out so that the blurry edge looks sharper.

Your lenses are now a telescope! Now that you know the trick, you can make a telescope whenever you find two different lenses lying around. If a friend happens to have two magnifying glasses, grab them, put the more powerful one right on your eye, move the other in and out, and you'll have an instant telescope.

## HOW TELESCOPES WORK

There are many different explanations of telescopes. Most of them are confusing and complicated. Some are even wrong. So, if you read an explanation and don't understand it, don't blame yourself. Blame the author of the book or encyclopedia for not being a good explainer!  A good explanation of a telescope should be easy to understand.

## A SIMPLE EXPLANATION:

If you put a lens right on your eye, it makes things blurry, but it does not magnify distant scenes. This is how eyeglasses work. They change the blurry-ness or sharpness of what you see, but they don't act as magnifiers when used normally. Now if you move a lens away from your eye, and keep looking through it, everything WILL change size. If the lens is concave (thinner in the center,) everything you see in the lens will get smaller and smaller as you move the lens farther away from your eye. If you use a convex lens instead, everything will get bigger and bigger as you move it away.

The convex lens is the interesting one because it makes things bigger when you move it farther from your eye. Keep moving it farther and farther away. You'll find that everything will become VERY big, even infinitely big. And infinitely blurry too. Move the lens a little farther, and things get small again, but now everything seen through the lens is upside-down.

By moving the convex lens in and out, we can change the size of everything, or make it all go upside-down or right side-up. Unfortunately everything is very blurry when you're looking through the lens. If only there was some way to remove the blurriness, we could hold a convex lens in front of our eye and use it to magnify distant scenes.

There is a way to remove the blur: wear glasses! Glasses are used to correct blurry vision, and they can fix this blur too. Put another lens right upon your eye. It acts like eyeglasses and makes the image sharp. If you do this, you have constructed a telescope. The objective lens creates a magnified view of distant objects, while the eyepiece lens removes the blur. That's how telescopes work.

## MAKE A TELESCOPE USING JUST ONE LENS

Here's an interesting question. If human beings could focus their eyes better, could we build telescopes with only one lens? Suppose you were able to focus your eyes on an object that was 1/10 inch away from your eye. Couldn't you hold an "objective" lens a few inches away, look through it, then focus really hard with your eyes and create a telescope? The answer is yes!

Even if you don't have a superhuman ability to over-focus your eyes, you can still make a simple one-lens telescope. Here's how. Hold a weak convex lens in front of your eye. Close your other eye. Move the lens far away so that everything turns upside-down. Move the lens a bit closer so that everything stays upside-down, but gets bigger and blurry. Now focus your eyes really hard by crossing them. (This might take a bit of practice! Crossing your eyes while one eye is closed is not that easy to do.)

The image you see in the lens will become sharper. If it doesn't become completely sharp, then move the lens farther away. Also try moving the lens closer while focusing really, REALLY hard. Everything you see in the lens will be clear, sharp, and magnified! You have made a telescope with nothing but a single lens! Tell your friends about it and they won't believe you. Then show them the trick and they'll be amazed.

## MAKE A TELESCOPE WITH A LENS AND SOME FOIL

It is also possible to make a telescope using aluminum foil and one lens. The lens will act as the telescope's objective lens. To make an eyepiece, we just poke a tiny hole in the foil, and use this pinhole as the telescope eyepiece lens. The tiny hole in the foil removes the blur. But it also makes the image very dim. That's alright, just use this telescope to watch a bright outdoor scene.

To make a good pinhole, stack up several layers of aluminum foil, poke the stack with a pin, then separate the layers and choose whichever one has a very round, very small hole. Experiment with different holes; put one on your eye, look through it a brightly-lit scene, and see how sharp everything looks. Smaller holes generally give sharper, dimmer images, but VERY small holes cause blur because of "optical diffraction" effects. You want your pinhole to be very small, but not so small that things become blurry.

To make a telescope, hold the best pinhole against your eye and look through it. Look at a brightly lit scene, such as the sunny outdoors outside a classroom window. Now place your objective lens against the pinhole, then move it slowly outwards. When you see a magnified scene, your telescope is working! You can hold your lens in different spots so the scene is either upside down or right side up.

An aluminum foil pinhole can be made sturdier by using rubber cement to glue it to a piece of cardboard which has a 1cm hole punched in the center (don't get cement in the tiny pinhole though!)

You can use your pinhole-telescope to create a "zoom lens" effect by moving the objective lens towards the pinhole or away. And depending on the distance between the pinhole and the lens, the scene you see can either be upside-down or right-side-up. It's very complicated to build a zoom-lens telescope with real eyepiece lenses, but if you use a pinhole it becomes simple.

### Get yourself some lenses:

American Science and Surplus sells inexpensive kits of miscellaneous lenses. Contact them at http://sciplus.com. Get a "large" kit for objectives, and a "small" kit for eyepieces. Edmund Scientific sells lenses too. Check out their website at http://www.edsci.com, and request a mail-order catalog. Get two convex lenses, one with 200mm focal length or more, and one with 75mm or less.

Resources: http://amasci.com/amateur/tele.html (Created by Bill Beaty)

Angel R. Uribe

“The Parachuters”

Objective: Compare the gravitational pull on different types of parachutes and the way  air reacts to the different shapes.

Materials: Paper, string, sticky tape, small unbreakable objects.

Construct: Several different types of parachutes. Fix object to the parachute with strings (4 pieces), 10 inches (25 cm) long.

Instructions: Choose a suitable high place (such as a chair or the side of a staircase) from which to drop the toy or other object to be parachuted. First drop the object and notice how long it takes to fall. Then try dropping it attached to 3 different kinds of parachutes:

1. A squashed-up ball made from an 8-inch (20-cm) square piece of paper.
2. A flat piece of paper the same size as the one you squashed.
3. A piece of paper 11 in. (35cm) square. (You can also make it  14 in.(35 cm) if possible).

Observation: Which parachute takes the longest time to fall? (Take care to drop the parachutes from the same height).

More things to try:

·        Longer strings

·        A hole in the top of the parachute

·        Different shapes (such as circles)

·        Different materials (such as plastic or cotton)

(Most Important: Have fun with it and be creative with your parachutes)

Joanna Hernandez

SCI.210

Dancing Coin

Time: 15 minutes

Materials:

Quarter

Glass Bottle

Objective: Students will be able to have a better understanding of heat transfer.

Review: Before the activity spend some minutes reviewing the idea of heating and cooling of air particles.

Procedure:

1. Pass out the bottle and quarter to each student. (Explain to them to not play with the bottles, they could break.)
2. Ask students to wet the rim of the quarter, or opening of the bottle.
3. Then, ask them to place the coin on top of the opening of the bottle.
4. With both hands ask the students to grip the body of the bottle as tight as they can.
5. After a few minutes the students should see the quarter lift/dance lightly.

Explanation:

This activity is intended to demonstrate the effects of heating of air particles. By placing your hands around the bottle, you are heating the air that is present within the bottle. If the students have a good understanding that when air is heated it expands, then they will understand that the warm air inside the bottle is expanding or attempting to get out. Because, it is trying to get out the quarter is being lifted to let some of the expanding air out.

This activity works with a plastic bottle also, but since glass is a better conductor of heat, it works better.

Joanna Hernandez

Balloon in a bottle

Time: 15 minutes

Materials:

Balloon

Two, 2 liter plastic bottle (One with and one without a hole at the bottom)

Objective: Students will have a better knowledge of air pressure.

Procedure:

1. Place the inflated balloon inside the plastic bottle without the hole. Place the lip f the balloon around the opening of the bottle.
2. Blow up the balloon inside the bottle. You will soon find out that you will not be able too.
3. Using the bottle with the hole follow the same procedure and blow up the balloon inside the bottle. This time you were successful to blow up the balloon.

Explanation:

Why were you able to blow up the balloon in one bottle and not the other? The reason is that even though it is not visible there is air present in the bottle. When you try to blow up the balloon, the air in the balloon is pushing at the air in the bottle and the air in the bottle is pushing back, this makes it difficult. The other bottle which contained a hole made it easier because, as you blew up the balloon the air in the bottle was being released through the hole.

The Fly Ball Game

Terry Liu

Materials:

-small cups

-pingpong balls

-tape

Procedure:

1. Place a ball inside one cup and blow air through the top of the cup. (Get leveled with the cup.)

2. Try to make the ball fly out.

3. Have a partner firmly hold down or tape down a second cup.

4. Place the cup with the ball in it approximately one cup away from the second cup.

5. Attempt to make the ball fly from the first cup into the second without moving anything.

6. The first group that makes five shots wins.

*Hint:  take turns to generate stronger air!

How does this work?

Bernoulli’s Principle:  Blowing air through the top of the cup creates fast air and changes the existing pressure into low pressure causing the ball to be pushed out.

SENDING SOUND

by Gaby Peniche

Concept: Sound waves- When a sound wave spreads out it passes its energy on from one tiny air molecule to the next. Sound waves need these tiny molecules in order to spread out.

Materials: 2 plastic cups for each student, & string

Instructions

Make a hole at the bottom of each cup. Tie a long piece of string into each cup, making sure you have a good knot so the string won’t slip through the hole. You should now have two cups attached to a string; you’ve just made a telephone cup. Have one student talk clearly into one cup, while the other student listens, make sure that the string is pulled tight or it won’t work. The student should be able to hear the other student.

How it Works

When your friend speaks into his or her cup, the air molecules in the cup vibrate causing the sides of the cup and string to vibrate. These vibrations pass along the string, eventually causing your cup to vibrate. These vibrations are detected by you ears and turned into sound.

Anna Fox

Two Kinds of Circuits

Parallel Vs. Series

Materials

Battery assemblies (battery, battery holder; either plastic with two battery conducting strips with electric clips or battery holders with clips attached)

Wire

Bulb holders

Small light bulbs

Objective

To provide an introduction to parallel and series circuits in a hands-on setting that enables students to experience the difference between these two types of circuits.

Parallel Vs. Series

In a series circuit there is only one path for the electric current to flow through the battery, bulbs, and wires.  The electricity flows from the battery through the wires and bulbs and back to the beginning.  In a parallel circuit there is more than one path for the current to travel by.

Arranging the Series Circuit

It is necessary before starting that all the students understand the materials and how to assemble them in a manner as to not create short circuits or cause.

The series circuit will require three pieces of wire, one battery, and two light bulbs in holders.  Attaching the wires to the clips on either pole of the battery holder we then attach each wire to a bulb holder clip on each of the bulb holders.  To complete the circuit we connect the final wire between the two light bulbs by way of their vacant clips.  The series circuit should light up easily and a faint light will be emitted form both small bulbs demonstrating the massive loss of energy in this circuit due to resistance.

Arranging the Parallel Circuit

The same two light bulbs with holders and the battery assembly will be used in the parallel circuit as well as one additional piece of wire.  We attach one light bulb to the battery assembly by clipping a wire from each clip of the bulb holder to each corresponding pole of the battery assembly, the light should illuminate as soon as the wires are fastened into the clips.  Next we attach two wires to either side of our second bulb holder and string those two wires to the clips of the bulb holder that is already in the circuit with our battery.  Connecting the second bulb holder to the first will immediately cause the second bulb to light up, but no change will be seen in the brightness of the first bulb when the second is added to the circuit.

Discuss with the students the observations they have made in regards to the brightness or dimness of the bulbs in both circuits.  Ask them to unscrew one bulb in the series circuit and note what happens to the second bulb.  During the parallel circuit assemblage ask them to repeat the motion of unscrewing one bulb and to observe what happens to the second bulb.  The disruption of the circuit by unscrewing the bulb in the series circuit will spark a discussion when the same action does not disrupt the parallel circuit when an attempt to unscrew one bulb is made.

The supplies for this activity can be found through Delta Education.

My dad, a third grade teacher, obtained these supplies through a science center program with LAUSD that was sponsored by the Department of Water and Power.  The teachers were given the supplies for this and many other activities free of charge.  Delta has a web site, the address is www.delta-ed.com.

Mirna Cardoza

Lab Activity

Question:

How is the sound different?

Material:

·        Scissors

·        String or yarn

·        Spoons

·        Forks

Procedure:

1.      Tie some spoons in the middle of a piece of string

2.      Jingle the spoons together.

3.      You will hear a tinkling sound as the spoons knock against one another.

4.      Now press the ends of the string hard against your ears

5.      Next, jingle the spoons again.

6.       How is the sound different?

7.      Clench the handle of an ordinary fork tightly between your teeth.

8.      Flick the ends of the prongs with your finger.

9.      You will hear strange twanging sound.

10.  Anyone watching you will hear only a faint flicking noise.

Conclusion:

The vibration from the spoons or the fork pass straight through the bones of your skull to reach your inner ear; The sounds are inside your head and you hear a much lauder deeper sound.

2 Point Discrimination