Chemical Reactions: Make A Penny Turn Green
Chemical Reactions: Make A Penny Turn Green
Chemical Reactions: Make A Penny Turn Green
Copper pennies
White vinegar
Dish or bowl
Paper towel
free observation printable (optional)
Clear glass
Water
Vegetable oil
Food coloring
Salt
Science Experiment Procedure
1. Fill your clear glass about 2/3 of the way with water.
2. Pour vegetable oil into your cup. (You want to create a layer thats about 3/4-1 inch high.) What happens to the oil after
you pour it in your cup? Why do you think this happens?
3. Add one drop of food coloring to the cup. What happens to the drop of food coloring? Why do you think this happens?
Water
Cooking oil (We used canola oil.)
Rubbing alcohol (optional)
Containers to hold the liquids (We used 4 oz Ball jars.)
Eye droppers
Toothpicks
Dish soap
Wax paper
Procedure
1. Use the eye dropper to place a few drops of water on some wax paper. Observe the drops closely. What do you notice?
2. Use another eye dropper to place some drops of cooking oil near the water drops. Compare the cooking oil to the
water. How are they the same? How are they different?
3. Look closely at other liquids like rubbing alcohol on the wax paper. Compare and contrast all the liquids.
4. Try poking the water drop with a clean toothpick. What happens?
Whats Going On?
The water drop on the wax paper looks kind of like theres a skin around it. When you poke it with a clean toothpick,
nothing happens, but, when you poke it with a soapy toothpick, the water spreads out.
Drops of water stick to each other. Thats why the surface of the water drops appear to have a skin-like layer on them.
This is called surface tension. Soap decreases the waters surface tension causing it to spread out.
Blank or old CD
Paper
Scissors
Tape
Pencil
Sunny day
Directions for Rainbow Science CD Activity
1. Find an area of your house or outdoors to do the activity. Youll want to be able to access sunlight with your CD and
have an area in the shade to reflect the rainbows. (If you dont have a blank wall, you can use a piece of white poster
board.)
2. Use the shiny side of the CD to reflect the sunlight onto your poster board or blank wall and notice the rainbow. What
does it look like? Notice the shape and colors. What happens when you change the angle of the CD?
3. Now the super fun part! Trace your CD a few times onto paper so you have circles the exact size of your CD and cut
them out.
4. Cut out various snowflake shapes using the paper circles. (You can see our tutorial on how to make paper snowflakes
here.)
5. Tape one of your paper snowflakes over the shiny side of the CD and reflect the sunlight onto your poster board or
wall. How do the patterns of light look different than before?
6. Try out your other paper designs.
1. If youll be painting your paper towel roll, youll want to do that first and let it dry. (This step isnt necessary, but its
hard for us to pass up an opportunity to paint something!)
2. Use a craft knife (an adult should do this) to cut a thin slit at a 45 angle toward the bottom of the cardboard tube.
3. Directly across from the slit, make a small peephole or viewing hole using your craft knife (another step for an adult).
4. Trace one end of your paper towel roll onto your small scrap of cardboard or cardstock. Cut it out.
5. Cut a straight slit right across the center of your cardboard circle.
6. Tape the circle to the top of your spectroscope.
7. Insert the CD into your 45 angled slit with the shiny side facing up.
Using the Homemade Spectroscope
Start by taking your spectroscope outside. Point the top slit up at the sky (NOT directly at the sun). Look through the
peephole. You will see a rainbow inside!
Now try your spectroscope with other light sources like fluorescent light, neon light and candle light. Compare what you
see!
Whats going on?
A CD is a mirrored surface with spiral tracks or pits. These tracks are evenly spaced and diffract light (separating the
colors). Because the CDs surface is mirrored, the light is reflected to your eye.
6. Making Rainbow Reflections
Materials for Rainbow Reflection Science for Kids
Flashlight
CD
Blank white paper
Procedure for Exploring Rainbow Reflections
Look carefully at the blank side of a CD. What do you see? What happens when you tilt it back and forth?
Find a dark room in your house. Place the CD on the floor.
Tape a piece of white paper to your wall. Aim the flashlight at the CD so that it makes the rainbow reflect onto your blank
paper. What colors do you see? What different patterns can you make by moving the flashlight around?
Question to Spark More Curiosity & Critical Thinking
How do you think the colors are getting onto the paper?
Experiment with changing the distance from the CD to the paper. What happens? Why?
Whats Going On
White light (like light from the flashlight) is made up of 7 colors (red, orange, yellow, green, blue, indigo, violet). The CD
separates the white light into the 7 colors that make it up, where they then reflect onto the wall. A CD is made of
aluminum (and covered with a clear coat of plastic.) It also has ridges in the metal which the light reflects off of.
Clear bottle (We used empty, plastic Voss water bottles like these that we found at our local grocery store.)
Water
Oil (vegetable oil or baby oil)
Food coloring
Optional: Super glue
Optional: Free printable recording sheet
Directions for Exploring Liquid Density with Sensory Bottles
1. Fill your bottle about halfway with water. Fill the other half with oil. What happens? Record your observation on the
recording sheet.
2. Be sure your bottle is closed completely and gently shake it a couple of times. Observe what happens over the next few
minutes. Record what you see.
3. Open your bottle and add a few drops of food coloring. What do you notice? Record your observations.
4. Gently shake the bottle a few times and record what you see.
5. What else could you add to your sensory bottle to observe? Try some of the ideas below (or your own idea) and record
your observations on the recording sheet.
Whats Happening?
Oil and water have different densities. Because the oil is less dense it rises above the water. When you add the food
coloring, it only colors the water because it is a water-soluble dye.
observe that no matter which way he tilted the stick or how steep an angle he tilted the stick, the paperclips
always pointed right down at the ground!
We talked about how the Earths gravity is what holds us and other things to the ground. The paperclips are being
pulled toward the Earth by gravity, but they cant fall because the string is holding them in the air. No matter
which way we tilted the dowel rod, the paperclips were still being pulled straight toward the Earth by gravity.
Next we explored how gravity can easily be overcome by other forces using magnets.
3. Place three magnets along a metal ruler. (If youre using a wooden ruler, you can tape the magnets to the top.)
4. Suspend the ruler from two stacks of blocks, books, or other materials. Be sure the magnets are facing down.
5. Take the paper clips and string off your dowel rod.
6. Take one paperclip and hold it until its just suspended below the first magnet. Tape the string in place onto the table
(or whatever surface your activity is on). Do this with the other two paperclips.
7. After taping the strings in place below the magnets, remove the ruler and observe what happens. All the paperclips fall
to the ground! We talked about why the paperclips were not going up into the air after we removed the magnets.
8. Put the ruler with magnets back above the paperclips. Slowly lift each paperclip toward each magnet until they
are all suspended. The kids were very excited about this demonstration!
We talked about how the magnetic force between the paperclip and magnet were stronger than the pull of the Earths
gravity on the paperclip, so the paperclip was able to remain in the air rather than fall back to the ground.
1. Fill a baggie about 3/4 of the way full with water and seal it shut.
2. Make sure your pencil is sharpened. (The sharper the better!)
3. Hold up the baggie with one hand and use the other hand to firmly push the pointy end of the pencil through the
side of the bag. Continue pushing it until the point is also coming out the other side of the bag.
4. Observe what happens!
Is this what you expected to happen? Why or why not? What do you think will happen when the pencil is pulled
out of the baggie?
No water spills out the holes because ziploc bags are made of a polymer. Polymers have long chains of molecules
that are flexible. When you poke a sharp pencil through the baggie, the pencil slides in between the chain of
molecules that make up the polymer. The molecule chains make a seal around the pencil that wont let the water
out.
Egg in a bottle
What you need
1 x hard boiled egg
1 x glass bottle with a wide neck (just wide enough to sit the egg in)
Boiled water from the kettle
our boiling water into the bottle to about a third of the way up.
Place the hard boiled egg so that it sits in the neck of the bottle.
Watch and wait. You will notice the egg gets shifted by the hot air in the bottle, this is when the hot air
expands and escapes a bit.
The egg will eventually get sucked into the bottle.
Why is it so?
The hot air from the hot water expands and forces its way out of the bottle, making the egg shift around.
As the air cools inside the bottle the air contracts and takes up less room. This creates lower pressure inside
the bottle than outside. The greater pressure outside the bottle forces the egg into the bottle.
Hints and tips:
To get the egg back out of the bottle, tilt the bottle and blow air into it. Watch out though, because the egg
will shoot out of the bottle!