Kids in Science

The Exploding Sandwich Bag

What you will need: -sandwich sized ziplock bag -1/4 c warm water -1/2 c vinegar -1T baking soda - toilet paper Tear off a square or two of toilet paper and put a tablespoon of

baking soda in the middle.  Twist or fold the toilet paper around
the pile of baking soda making a small packet.
Next, open your sandwich bag and pour in 1/2 cup vinegar and
1/4 cup warm water. Zip the bag closed, but not all the way.
You'll want a small opening just large enough to drop in the
packet of baking
soda.  Move the experiment to the sink or outside!  Put the baking
soda packet into the bag and then quickly zip it all the way
closed.  (I found it helpful to carefully put the packet in, then
hold it towards the top away from the liquid so I could zip the
bag all the way closed, then let it drop in)
Once the bag is sealed, give it a quick, gentle shake so the
packet drops into the liquid and set it down.  The reaction will occur
almost immediately and the bag will start to fill with carbon dioxide
It'll get bigger and bigger until it finally POPS! Site I borrowed this from: http://www.cometogetherkids.com/2012/02/exploding-sandwich-bag-experiment.html Swirling Colors Milk What you will need: -milk (whole or half and half - skim won't work) -tray or shallow bowl -food coloring -cotton swabs -liquid dish soap (dawn works well) Pour some milk into your tray.  You'll want it at least 1/4" deep. Add several drops of food coloring near the center of the tray. Dip a cotton swab into the color (don't stir it, just dip!).  Nothing really happens. Now, dip your cotton swab into your liquid dish soap and then dip back into your milk.   (again, don't stir, just dip it in and hold it in place for a few seconds!).  Watch how the colors "jump" away from the soap, and then begin swirling around on their own!

Make Slime!
What You Need:
•borax powder
•water
•4 ounce (120 ml) glue (e.g., Elmer's white glue)
•teaspoon
•bowl
•jar or measuring cup
•food coloring (optional)
•measuring cup

Here's How:
1.Pour the glue into the jar. If you have a big bottle of glue, you want 4 oz or 1/2 cup of glue.
2.Fill the empty glue bottle with water and stir it into the glue (or add 1/2 cup of water).
3.If desired, add food coloring. Otherwise, the slime will be an opaque white.
4.In a separate, mix one cup (240 ml) of water into the bowl and add 1 teaspoon (5 ml) of borax powder.
5.Slowly stir the glue mixture into the bowl of borax solution.
6.Place the slime that forms into your hands and knead until it feels dry. (Don't worry about the excess water remaining in the bowl.)
7.The more the slime is played with, the firmer and less sticky it will become.
8.Have fun!
9.Store your slime in a zip-lock bag in the fridge (otherwise it will develop mold).

Tips:
1.Use white glue, such as Elmer's brand. Most 'school glues' do not have the correct composition.
2.Don't eat the slime - it isn't especially toxic, but not good for you either!
3.Slime cleans up pretty easily. Remove dried slime after soaking with water.

Make Crystal Spikes!
Difficulty: Easy
Time Required: 1-3 hours

What You Need:
•black construction paper
•pie or cake pan
•warm water
•Epsom salt
•scissors

Here's How:
1.First, a sunny day isn't required, but it will help! You want rapid evaporation of the water to form the crystals, so select a warm, dry place to grow crystals (sunny porch or window is great).
2.Use the scissors to cut black (or other dark color) construction paper so that it will fit in the bottom of the pan.
3.Add 1 tablespoon of Epsom salt to 1/4 cup warm water. Stir until the salt is dissolved.
4.Put the construction paper in the pan and pour the salt solution over the paper.
5.Put the pan in the place you have selected for crystal-growing. As the water evaporates, you'll see lots of spiky crystals.
6.Have fun! Use a magnifying glass to see your creations up-close.
Tips:
1.This is one of the fastest, least toxic methods of growing crystals. You can substitute regular salt for Epsom, but the resulting crystals won't be as exciting.
2.Wash your hands after handling Epsom salts. Don't drink the solution and avoid spilling it on yourself.
3.Experiment with adding water colors or food color to the salt solution.

Make Playdough!

Difficulty: Easy
Time Required: 15 mins.
What You Need:
•1 c flour, sifted
•1/2 c salt
•3 T cooking oil
•1 pkg Koolaid (unsweet)
•1 c boiling water
Here's How:
1.Mix together flour, salt, oil, and Kool-aid.
2.Add the cup of boiling water. Mix well.
3.Knead the mixture until it forms a soft dough.
4.Have fun!
5.Store in a sealed container in the refrigerator.
Tips:
1.Any other unsweetened, powdered drink mix may be substituted.
2.Expect colored hands :-)
3.Non-toxic... could be eaten, but won't taste very good.

Make Invisible Ink!
Difficulty: Easy
Time Required: A Few Minutes

What You Need:
•Baking Soda
•Paper
•Water
•Light Bulb (heat source)
•Paintbrush or Swab
•Measuring Cup
•Purple Grape Juice (opt.)

Here's How:
1.There are at least two methods to use baking soda as an invisible ink. Mix equal parts water and baking soda.
2.Use a cotton swab, toothpick, or paintbrush to write a message onto white paper, using the baking soda solution as 'ink'.
3.Allow the ink to dry.
4.One way to read the message is to hold the paper up to a heat source, such as a light bulb. The baking soda will cause the writing in the paper to turn brown.
5.A second method to read the message is to paint over the paper with purple grape juice. The message will appear in a different color.

Tips:
1.If you are using the heating method, avoid igniting the paper - don't use a halogen bulb.
2.Baking soda and grape juice react with each other in an acid-base reaction, producing a color change in the paper.
3.The baking soda mixture can also be used more diluted, with one part baking soda to two parts water.
4.Grape juice concentrate results in a more visible color change than regular grape juice.

Make Baking Soda Volcano!
Okay, the baking soda volcano is the kitchen equivalent of a volcano, not a real one. It's cool all the same! The baking soda volcano is also non-toxic, which adds to its appeal.
Difficulty: Average
Time Required: 30 minutes

What You Need:
•6 cups flour
•2 cups salt
•4 tablespoons cooking oil
•warm water
•plastic soda bottle
•dishwashing detergent
•food coloring
•vinegar
•baking dish or other pan
•2 T baking soda

Here's How:
1.First make the 'cone' of the baking soda volcano. Mix 6 cups flour, 2 cups salt, 4 tablespoons cooking oil, and 2 cups of water. The resulting mixture should be smooth and firm (more water may be added if needed).
2.Stand the soda bottle in the baking pan and mold the dough around it into a volcano shape. Don't cover the hole or drop dough into it.
3.Fill the bottle most of the way full with warm water and a bit of red food color (can be done before sculpting if you don't take so long that the water gets cold).
4.Add 6 drops of detergent to the bottle contents. The detergent helps trap the bubbles produced by the reaction so you get better lava.
5.Add 2 tablespoons baking soda to the liquid.
6.Slowly pour vinegar into the bottle. Watch out - eruption time!

Tips:
1.The cool red lava is the result of a chemical reaction between the baking soda and vinegar.
2.In this reaction, carbon dioxide gas is produced, which is also present in real volcanoes.
3.As the carbon dioxide gas is produced, pressure builds up inside the plastic bottle, until the gas bubbles (thanks to the detergent) out of the 'volcano'.
4.Adding a bit of food coloring will result in red-orange lava! Orange seems to work the best. Add some red, yellow, and even purple, for a bright display.
5.If you need more detailed instructions or information about the chemical reactions involved in the volcano, I also have a step-by-step tutorial and a video tutorial.