Student Reports for Winter 2004

 

Black Magic

Arlene X. Ramirez

Objective:

To find out what make up the color black.

What do I need?

  1. White coffee filters
  2. Black marker (not permanent)
  3. Water
  4. Plastic cups
  5. Small rubber bands

Instructions to class:

  1. Fold the coffee filter in half and the in half again creating a shape of a cone or a rounded edge triangle.
  2. Fill cup half-way or less with water
  3. Draw with a black marker a line about one inch from the pointed edge and then draw designs on it, ( on both signs)
  4. Put the pointed side of the filter in the water. You just need to put the tip in the water. Let the water soak all the way up the coffee filter.
  5. Observe what is happening
  6. Open up your coffee filter and allow it to dry. Take your rubber band and make the coffee filter into a butterfly shape by tying the rubber band around halfway through the coffee filter.

I do as previous explained, (same as class).

What’s going on?

Most non-permanent markers use inks that are made of colored pigments and water. On a coffee filter, the water in the ink carries the pigment onto the paper. When the ink dries, the pigment remains on the paper.

In this experiment, you’re using a technique called chromatography. The name comes from the Greek words chroma and graph for "color writing." The technique was developed in 1910 by Russia botanist Mikhail Tvset. He used it for separating the pigments that made up plant dyes.

There are many different types of chromatography. In all of them, a gas or liquid (like the water in your experiment) flows through a stationary substance (like you r coffee filter). Since different ingredients in a mixture are carried along at different rates, they end up in different places. By examining where all the ingredients ended up, scientists can figure out what was combined to make the mixture.

Why does mixing many colors of ink make black?

Ink and paint get their colors by absorbing some of the colors in white light and reflecting others. Green ink looks green because it reflects the green part of white light and absorbs all the other colors. Red ink looks red because it reflects the red light and absorbs all the other colors. When you mix green, red, blue, and yellow ink, each ink that you add absorbs more light. That leaves less light to reflect to your eye. Since the mixture absorbs light of many colors and reflects very little, you end up with black.

Hanh Nguyen

Straw Instruments

 

Grade Level:     Appropriate for Elementary Age grades 2-5

Time:                Activity will last about 15-20 minutes

Materials:         Straws, Ruler, Scissors, and Tape

Teacher Preparation:  May prepare the pieces of tape cut to wrap the straws

 

Purpose:                       To guide students in investigating and observing the sound effects

That occurs when there is a change in the size and length of the straws.  This will also teach students the notion of vibration and pitches that are made by blowing air into the straws.  In addition, it also allows students to practice their measuring skills.

 

Procedure:

  1. Students gather the materials, scissors, 3 straws, ruler, and a piece of masking or clear tape that is about 8cm long. 
  2. Find the side of the ruler that marks the centimeters (cm).
  3. Then take one straw and place it against the ruler to measure 5cm and cut the straw at the mark.
  4. Then using the remanainder of the straw measure and cut off 10cm.
  5. Next take a new straw and place against the ruler to measure 6cm and cut it.
  6. Then with the same straw, measure and cut 9cm.
  7. Take a new straw and measure and cut 7cm.
  8. Next take the remainder of the straw to cut off 8cm of the straw.
  9. When all the pieces of straws are cut to the five different lengths, place them in order from the shortest to the longest.
  10. Wrap tape around the straws to hold them in place.  When wrapping the tape leave about 1cm from the tip.  All straws are lined up next to each other.
  11. With out putting your lips on the straws, blow into them pulling the instruments from side to side so that you may hear the different sounds created. 
  12. Different types of straws my also be done to compare with the previous using the same procedures.

 

Critical Thinking:

What is a pitch?  What is sound?  What can we conclude about the lengths of the straws and how it affects the sound of the straw?  Does the texture and size of the straw change the sounds?  What kind of instrument can we relate this to?

 

Conclusion:       We can conclude that sound is effect by many variables.  The level of which air is blown into the straw; the shape and size of the straw all make a difference in the outcome of the sound. 

 

 

This activity is fun to do and the materials are easy to get.  Children enjoy exploring the different sounds of things.  It is also a great way for them to learn about vibrations and measurements.  Also it is something that they can take home and play with.

 

 

Will the Candy Sink or Float?

Jeanette Mancilla

Purpose

1. To allow the students to do hands on experiment using lessons taught in class: density, buoyancy, and gravity.

2. The students will also be able to make a hypothesis, test, and conclude as to what are the properties of an object, which will float.

3. Test Archimedes Principle.

 

Materials

-         Container (bowl, bottle cut in half, cup, etc.)

-         Water

-         Candy: Mints (hard candy)

       Starburst Fruit Chews

       Milky Way Miniatures

       Twix Miniatures

        Kit Kat Bites

  Time

-         Depending upon how many objects selected, 10-20 minutes

 

Instructions

1.     Working in groups of two or three, make predictions as to whether the provided objects will sink or float.

2.      Make a chart and record your answers on the board.

3.     Test each of the objects separately, and record your answers on the sheet provided.

4.     After testing the objects record your findings on the board.

 

Conclusion

-Why do you think that certain objects float while others sank?

Density: mass/volume

Buoyancy: the upward force that liquids exert against an object,

Archimedes Principle

Displacement: the volume of water moved by a floating or sunken

Object.

 

                        EGG

         DROP

(Lauren Perigan)

Objective: To introduce students to air pressure and its affect on                                        the objects around us.

Materials:

·         A peeled hard-boiled chicken egg

·         A glass bottle or vase with a wide opening (opening should be slightly smaller than the width of the egg)

·         Matches

Procedure:

·         Place the peeled egg on top of the bottle or vase to show others that it will not fit through the opening.

·         Light two matches and let them burn for 5-10 seconds.

·         Lift the egg from the bottle or vase and drop the burning matches into the bottle.

·         Replace the egg immediately. (The egg may jump a little, but don't touch it…just watch and see what happens.)

Follow up:

·         Allow the students to explain why the egg went into the bottle. (As the air was heated, it began to expand. Some of the air escaped and may have caused the egg to wobble. When the fire was extinguished, the air began to cool and contract. The egg has now sealed the bottle. There is now less air in the bottle causing unequal pressure to occur between the air in the bottle and the air outside the bottle. The greater air pressure on the outside pushes the egg into the bottle equalizing the air pressure inside and outside the bottle.)

·         Define air pressure: air pushes on all surfaces that it touches. This push is called air pressure. (It may be helpful to talk about these subjects before the experiment so that the students may predict the air’s behavior more accurately.)

·         Allow students to brainstorm how to get the egg out of the bottle without breaking the bottle or the egg. (Hint: turn bottle upside down and gently heat the closed end of the bottle and keep the open end cool.)

·        Let students get in small groups to come up with another way to get the egg in the bottle besides the procedure that we used. Discuss the methods as a class and determine which method may work better.

 

 

Sonya Yoo

Experiment # 25

 

Purpose: To teach students about surface tension and show how it applies to water. 

 

Materials: Two 2 liter soda bottles for each group of students, duck tape, water, glitter (optional), food coloring (optional). 

 

Procedures:

-Give each group of students (2-4 students is a good size) two 2 liter soda bottles without the caps.

-Have the students fill one of the bottles ¾ with water.  If the bottle already has soda in it and the students wish to keep the color of the soda, the students can leave a little soda in it and fill it with water until the bottle is ¾ full with liquid.

-Place the bottle with liquid in it on a flat surface.  Take the other empty bottle and place is upside down on the filled bottle so that the openings of the bottles are together. 

-Duck tape the two bottles together tightly so that there is a firm seal.  Make sure there is no significant amount of water when shaken.  If there is make sure to seal the leaks with duck tape. 

-Take the taped bottles to an area that can get wet.  Turn the taped bottles upside down and give it a strong swirl.  What happens?

Explanation: When the bottles are given a strong enough swirl, a whirlpool (vortex) is created in the bottle.  The reason why the water does this is because water has a high surface tension.  Surface tension is the cohesive forces between liquid molecules.  The cohesive forces between molecules in a liquid are shared with all of the atoms surrounding the molecules.  The molecules on the surface have no neighboring atoms on top so they form stronger forces on the neighboring atoms on the surface.  This is surface tension.  The higher the surface tension, the more the molecules want to stick to each other.  The surface tension of water decreases significantly with temperature Surface tension is usually measured in dynes/cm., which is the force in dynes required to break a film of length 1 cm.  The surface tension of water is 72 dynes/cm. at 25°C. 

Things to think about:

-Will having objects in the water disturb the experiment?

-Once the whirlpool is spinning downward and the bottles were to be spun in the opposite direction, what would happen to the whirlpool?

-Would the same thing happen if the hole was smaller/bigger?

-If duck tape was used to shut one of the mouths closed and holes were put in it, would it have the same effect as the original experiment?

*Another experiment that involves surface tension in water: Have enough people in a swimming pool to border the swimming pool wall.  The people swim in a constant circle going the same way.  A small whirlpool is created. 

 

 

Anne Tseng

The Mysterious Moving Ping-Pong Ball

Area of science: Physics

Grade level: 4 – 6

Strategy: in pairs or small groups

Time: 15 – 20 min.

 

Overview:

Static electricity is based on the structure of the atom.  An atom contains tiny positively charged particles called protons in its core and much smaller negatively charged particles called electrons, which revolve around the outside.  Objects with opposite charges (positive and negative) will attract one another, while objects with like/same charges will repel.

 

Purpose:

            To teach and help students gain a better understanding of “static electricity” using everyday objects.

 

Materials:

 

Procedure:

  1. Place the ping-pong ball on a smooth flat tabletop. 
  2. Rub the blown-up balloon against your hair a few times. 
  3. Bring the balloon near but not touching the side of the ping-pong ball.  Slowly move the balloon away from the ping-pong ball.
  4. See how far you can make the ping-pong ball travel (in one direction).  Measure the distance with your ruler or tape measure.
  5. Record your results:

 

 

The # of times you’ve rubbed the balloon

 

The distance the ping-pong ball traveled

5

 

10 – 15

 

30 and up

 

 

Extras:

Contest #1 -

A.      The goal is to get your ping-pong ball from one end of the table to the other end as fast as you can.

B.       Place the ping-pong ball at one end of the table.

C.       You may rub the balloon as many times as you want during the race.

D.      The first team to get the ball to the other side wins!

 

Contest #2 - 

A.      Place the ping-pong ball at one end of the table.

B.       Given 1 minute, rub the balloon against your hair as fast or as many times as you can.  (You will not be allowed to “recharge” during the race.)

C.       When time is up, try to move your ball as far as you could (as close to the other end as possible).

D.      The team that moves the ball closes to the finish line (the other end) wins!

 

Questions to think about:

1. Do you think the ping-pong ball would have followed the balloon if you hadn’t rubbed the balloon against your hair?

2. Try using other objects (comb), did they cause the same effect as the balloon?

3. What would happen if you have two objects of the same charges?  Would they attract or repel one another?

4. Try this at home: Make a very thin stream of water come out of your kitchen faucet.  Comb your hair a few times and slowly bring the back of the comb toward the thin stream of water (do not let the comb touch the water).  What does the water do?  What do you think would happen if the comb got wet?

 

Conclusion:

In the following activity, only one object (the balloon) is rubbed and charged with static electricity.  It is then used to attract an uncharged/neutral object (the ping-pong ball).  Opposite charges (positive and negative) attract while like charges (positive and positive or negative and negative) repel.   

 

 

Crystal Caskey

Jumping Rice: Static Electricity

 

Targeting Grade Levels:  2-4

Key Science Topics: 

Charging electricity by friction and contact, static electricity

(electrons being transferred by friction when one material rubs against another)

Learning Outcomes:  Observing, investigating, scientific method

Time Required: 15 min, 5 for setup and cleanup

Materials for each group of students:

·       Small cup of Rice Krispies

·       Balloon

·       Paper plate

Procedure:

·       Have the students recognize a question or a problem about charging electricity.  (What would happen when one material rubs against another?)

·       Have the students make and educated guess-hypothesis

·       Let the students blow up their balloons

·       Have the students charge their balloons by rubbing the balloon on their heads or on a wool cloth

·       Let the students observe charging their own electricity by the attractive and repulsive forces

·       Have the students empty a cup of Rice Krispies onto their plates and ask them to charge their balloons so that they can attract the Rice Krispies onto their balloons.

·       Let the students observe the jumping rice and have them make some conclusions or experimental findings.

Teacher’s explanation to students about where electric charges come from:  Material objects are made up of atoms.  They are composed of electrons, protons, and neutrons.  Normally objects have equal numbers of electrons and protons so they are electrically neutral.  Now, if there is a little imbalance in the numbers, the object becomes electrically charged.  An imbalance occurs when electrons are added or removed from an object.  When you comb your hair, electrons transfer from your hair to the comb.  Scuff your shoes across a rug and feel a shock as you reach the doorknob.    *

 

 

Donna Caspio

The Bubble Bomb

Time: 15-20min

Grade level: 5-6

 

Materials needed

 

Experiment

Next, hold the packet at the top of the bag until sealed.  Once the bag is sealed            drop the packet and shake it lightly

 

What’s is happening?

The bubbles in the Bubble Bomb are filled with carbon dioxide, a gas that forms when the vinegar (an acid) reacts with the baking soda (a base)

 

Example: cake rising due to chemical reaction of an acid and base.  When you add the water and baking powder, it will fizz.

 

Some Questions to think about

1.      Instead of using a paper towel, make your “time release packet” using a coffee filter, what do you think will happen?

2.      Does changing the water temperature change your experiment?

 

 

Balloon Races

By:  Vanessa Galassi

 

 

Grade Level:  K-2

 

Objective:  Students will use inquiry and observational skills to determine Newton’s Third Law of Motion:  for every action there is a reaction; for every force there is an equal and opposite force.

 

Materials:  balloons, straws, tape, string

 

Construction and Procedure:  First, cut string that is about 5-6 feet long.  Put string though straw.  Blow up balloon (but hold the end) and tape balloon to the straw.  Hold onto the balloon end and one end of the string.  Tape the other end of the string to wall.  Or have the children get partners and have one child hold the end of the string.  Let go of the balloon and watch it rocket to the end of the string.  Have the children blow up different sizes of the balloon and see which one will go faster.  Have them hold the string in an upward or downward position.

 

Conclusion:  This activity demonstrates Newton’s Third Law of Motion.  The balloon is using air pressure to move forward.  By showing the students that when the air in the balloon is pushed out of the balloon, the escaping air pushes forward on the balloon, which makes it go forward.  Students should also see that different amounts of air determine how fast or slow the balloon will travel.

 

 

19. Julie Halferty

Cooked Vs. Raw Egg

What You'll Need

One cooked egg
One raw egg

 

 

The Set up:

1)      Take two eggs out of an egg carton.

2)      Turn the heat on high until it comes to a boil (adding a bit of salt can speed up this process.

3)       Put one of the eggs into the pot. 

4)      Let it cook for about 20 minutes. 

5)      Take the egg out and run it under cold water right away. 

 

The Experiment:

It is difficult to identify from two similar looking eggs which one is cooked and which one is raw.  You do not want to make the mistake of cracking a raw one in hopes of eating a hard boiled egg, so there is a trick in figuring out which one is cooked and which is raw.

 

1) Spin each egg in turn on a plate.  The egg that continues to spin for a longer time is the        cooked one.

 

2) Now spin the eggs again, then quickly stop both of them.  Let go of both the eggs.  You will see that the cooked egg stays still but the raw egg starts to spin again.

 

What is the explanation behind this?
The contents of the egg have more inertia when they are raw, because they are in the form of a liquid. This inertia slows down the raw egg and that is why it stopped spinning before the cooked egg. In step 2, the liquid in the raw egg was still moving when you stopped both eggs, so that movement made the raw egg begin to spin again.

 

What is inertia?

Inertia is the sluggishness or apparent resistance of an object to change its state of motion.  Mass is the measure of inertia.

 

For future teachers:

This experiment is a simple and fun one to do with younger kids.  This would be a great way to teach kids the concept of inertia when studying weight or mass. 

 

 

 

 

*Paper Bridges*

Terry Liu

 

 

Materials:

        Plain paper (white printer paper)

        Paper clips

        Ruler

        2 books (per group)

        at least 100 pennies or other small weights

 

Introduce the Activity:

Briefly discuss basics of bridges. (What are some famous ones? What is the purpose of bridges?)

 

Activity:

 

1.Begin with a demonstration.  Hold up one sheet of paper and ask students to predict how many pennies a bridge made out of this paper can hold.  Place two books about 8 in. apart and place the paper flat across the two books.  Ask for a volunteer to come up and test the predictions.  When the bridge collapses with very few pennies, move the books closer and closer to test and see how much this single sheet of paper can hold.  Point out that clearly one single sheet of paper will not make a very good bridge.  Lead into the activity. 

 

2.Ask: Now what can you guys do to make a bridge that will hold as many pennies as possible with one sheet of paper?  (Group them and let them know they can use any method they want; cut, tear, paper clip, fold, etc.)

 

3.Whoever designs a bridge that can hold the most pennies will be rewarded for their ingenious work.  

 

Big Idea:

        Changing the shape of a material can change the way it resists forces.  Even though a piece of paper seems flexible and weak, it can be folded, rolled, twisted, or any other way altered to support a larger weight.  Folding helps the paper resist bending forces created by the load of pennies on top of the bridge. 

 

Hints:

- Folding the paper into accordion style is most successful.  Folding into an I-beam and paper-clipping the ends will be successful as well. 

-         Students will probably notice that the bridge can support more weight distributed along the bridge than at a single point.  

-          

Jeannie N. Ly

 

Title:  Center of Gravity – On the Move

 

Intro:

                You probably have tried to balance a ruler or something like that on your finger before or a book on your head before.  You might have noticed that the slightest change in movement causes the object to tilt and fall off.  Once your find the exact spot where the object is balanced, you have found the objects center of gravity.  The center of gravity is the exact spot of an object where there is an equal amount of weight on one side as there is on the opposite side.  One way to find an object’s center of gravity is to move the object around on the tip of your finger until it balances nice and flat w/o tilting in any direction.  The center of gravity can change when weight is added somewhere on the object. 

 

Materials Needed:

 

                3x5 index cards

                paper clips

                pencil, pen, or marker

 

Instructions:

 

  1. Look at the index card and think of where the center of gravity might be.  Remember this spot where the card would balance flat on your fingertip.
  2. Using a pencil, place a small dot to where you think the center of gravity is on the index card.  Hold the card up to see that you can see where you placed the dot.  Place the dot on the tip of your index finger to test whether or not the center of gravity is where the dot is.  If it does, congratulations – you found the center of gravity.  
  3. If the card does not balance, ask your partner to observe how the card tilts and in which direction.  From this observation, move the card to find the center of gravity.  Once you find it, have your partner mark that spot then.
  4. Attach a paper clip to the spot where number 1 is located on the card.
  5. Place one of those two dots created by you and/or your partner (depends if you both find different centers of gravity) and find the center of gravity as you did before with the paper clip attached to the paper.
  6. Observe how the card tilts and in which direction again.  Add a paper clip to any or more numbered areas on the card in any combination.  You and your partner should predict where you think the center of gravity might be.

 

Question:

 

  1. Do you think that the amount of weight or where the weight is placed mostly effects the location of the center of gravity?

 

 

Reference: 

 

The Best of Wonder Science:  Elementary Science Activity, Volume 1.  Albany, New York:  Delmar Publishers, 1997. (page 433 - 438)

 

 

 

 

 

CREATING LIGHT THROUGH FRICTION

BY ROSE LOPEZ

 

PURPOSE:     Introduce students to some basic principles involved in the concept of                                energy.  How energy can be transformed or converted from one form into another.

 

WHAT YOU NEED

 

WHAT TO DO

 

This experiment would be appropriate for sixth grade and above.  This is excellent lesson to begin discussing how electrons and protons generate positive and negative charges within an atom.  When the charged balloon touched the bulb, electrons moved from it to the bulb, causing the small sparks of light inside.  In normal operation, the electrons to the bulb from the electrical power lines through a wire in the tube.  This experiment generated enough energy through friction to light the bulb.

 

 

Geodesic Gumdrops

Diana Ramirez

SCI 210/L

 

Objective:  The students will learn about compression and tension by building their own structures.  They will also learn how to make strong structures in compression and tension.

 

Materials:  Gumdrops and round toothpicks

 

What is tension and compression?

Tension is a pulling force.  It is when material stretches out.

Compression is a pushing force.  It is materials get squashed.

 

Let’s Make Square and Cubes!!!

1.        Start with 4 toothpicks and 4 gumdrops.  Poke the toothpicks into the gumdrops to make a square with a gumdrop at each corner.

2.       Poke another toothpick into the top of each gumdrop.  Put a gumdrop on the top of each toothpick.  Connect the gumdrops with toothpicks to make a cube.  (A cube has a square on each side.  It takes 8 gumdrops and 12 toothpicks.)

3.       Use more toothpicks and gumdrops to keep building squares onto the sides of the cube.  When your structure is about 6 inches tall or wide, try wiggling it from side to side.  Does it feel solid, or does it feel kind of shaky?

 

Making Triangle and PyramidsStart with 3 gumdrops and 3 toothpicks.

1.      Poke the toothpicks into the gumdrops to make a triangle with a gumdrop at each point.

2.       Poke another toothpick into the top of each gumdrop.  Bend those 3 toothpicks in toward the center.  Poke all 3 toothpicks into one gumdrop to make a 3-sided pyramid.  (A 3-sided pyramid has a triangle on each side.  It takes 4 gumdrops and 6 toothpicks.)

3.       Use more toothpicks and gumdrops to keep building triangles onto the sides of your pyramid.  When your structure is about 6 inches tall or wide, try wiggling it from side to side.  Does it feel solid, or does it feel kind of shaky?

 

Making 4-Sided Pyramids

            You can make a very big structure out of squares and cubes, but it’ll be wiggly and will probably fall down.  If you try to make a structure out of only triangles and pyramids, it won’t be wiggly, but you’ll probably run out of gumdrops and toothpicks before it gets very big.  A 4-sided pyramid has a square on the bottom and triangles on all 4 sides.  When you make a structure that uses both triangles and squares, you can make big structures that are less wiggly.

1.        Build a square, then poke a toothpick into the top of each corner.

2.       Bend all 4 toothpicks into the center and connect them with one gumdrop, to make a 4-sided pyramid.

3.       What other ways can you use squares and triangles together?  How big a structure can you make before you run out of gumdrops?

 

What’s going on?

          Stretching and Squashing---Some Basic Principles

Even though your gumdrop structures are standing absolutely still, their parts are always pulling and on each other.  Structures remain standing because some parts are being pulled or stretched and other parts are being pushed or squashed.  The parts that are being pulled are in tension.  The parts that are being squashed are in compression.

Sometimes you can figure out whether something is in tension or compression by imagining yourself in that object’s place.  If you’re a brick and someone piles more bricks on you, you’ll feel squashed and you’re in compression.  If you’re a rubber band and someone stretches you out you’ll feel being pulled apart and you’ll be in tension.

As you’ve probably already discovered, squares collapse easily under compression.  Four toothpicks joined in a square tend to collapse by giving way at their weakest points.  A square can fold into a diamond.

But if you make a toothpick triangle, the situation changes.  The only way to change the angles of the triangle is by shortening one of the sides.  So to make the triangle collapse you would have to push hard enough to break one of the toothpick.

If you want to, you can use your gumdrops and toothpicks to build some strong structures that are made by combining triangles and squares.  The pattern you should try to get is one similar to some used in modern bridge design.

 

 

Brandi Soto

HILARIOUS HONKER

 

Area of Science: Physics

Grade Level: 4-6

Strategy: Alone or in pairs

Time: 15 – 2