Exploding Bags

Exploding Bags

What you need:Exploding Bags1
• sandwich plastic ziplock bag
• 1/2 cup vinegar
• 1/4 cup warm water
• paper towel
• 1 1/2 TB spoon baking soda

What you do:Exploding Bags2
• Tear your paper towel into a 5×5 inch square.
• Place  baking soda into the middle of the square.
• Fold the sides of the square into the middle to create a packet.
• Pour  1/2 cup of vinegar and a 1/4 cup of warm water in the sandwich plastic bag.
• Begin zipping the bag closed.
• When it is half closed drop your time release baking soda packet in and quickly close the rest of the bag.
• Shake the bag a little and then place it on the ground.
• Watch as it begins to fill with air as the baking soda and vinegar react. The bag will fill with air until it bursts with a grand POP!

Water Density

Water density cover

What you need:Water density
• Clear glass or Jumbo Test Tube
• Pipettes or droppers
• Sugar
• Measuring spoons
• Food coloring
• 4 small cups

What you do:
• Fill your cups with 1 cup of warm water and add food coloring to the water.
• Add 2 tablespoons of sugar to the 1st cup, 4 tablespoons to the 2nd cup, 6 tablespoons to the 3rd cup and 8 tablespoons to the last cup.
• Label each cup with the amount of sugar added.
• Stir the water until the sugar is dissolved.
• Start with the cup with the most sugar. Using a pipette, dropper or back of a spoon, begin adding the first layer of sugar water.
• After the first layer, things get challenging. Carefully drip the next dense layer onto the surface of the first. The best technique is to place the pipette right above the surface of the first layer and against the glass. Slowly drip the next color onto the first. This will take a lot of patience. Go slow.
• The colors will begin to mix at first and then your original color will start to show.
• Repeat with the next dense color and the least dense color until you have stacked all of the colors.

NB.: The more sugar you add to the water, the more sugar molecules will take over the space, making the water more dense. The cup containing the 5 tablespoons of sugar will be the most dense, the cup with 1 tablespoons will be least dense. That is why we layer them with the most dense liquid at the bottom and the least dense at the top.

Apple Science

Apple Science Cover

What you need:Apple Science1
• Baking sheet or wax paper
• Labeling tape
• Pen or marker
• Tongs
• Bowl
• Knife
• Lemon juice
• Vinegar
• Water
• Salty water
• Dishsoap
• Oil
• Apple

What you do:
• Use the tape to create labels for each type of liquid you will test.
• Place your labels on the baking sheet or wax paper.
• Cut the apple into slices at least 1-cm thick.
• Set out a slice of each food item on the baking sheet or was paper under the heading “Control.”
• Fill the bowl with enough liquid to fully submerge each sample.
• Dip a slice into the liquid with tongs. Be sure to cover the whole slice! Let the extra liquid drip off before placing it under the correct label on the baking sheet or wax paper.
• Rinse out the bowl and repeat until you have made samples with each liquid.
• Record all your observations, taking note of the time.

NT.:  The food’s skin protects the inside “meat” of the fruit or vegetable from damage and debris. When a fruit or vegetable is dropped and the skin is poked or broken, the food often goes bad faster. The reason fruits and some vegetables go brown when they are cut is because the part containing the oxygen-reactive enzyme is exposed. There is then a lot of surface area for the air to come in contact with the food. For the most part, brown fruits and vegetables still taste fine, they just do not look very appetizing.

Acids prevent browning because they react with the oxygen that comes into contact with the surface of the sample. Once all the acid (or whatever else is covering the surface) has reacted with the oxygen or the acid has degraded or washed off, then the sample will start to brown again. Stronger acids, like lemon juice, can even denature the enzyme. This means that the enzyme can no longer perform its original function because of its environment.

Cipher Wheel

Cipher Wheel Cover

What you need:Cipher Wheel
• Poster board or two small paper plates
• Scissors
• Ruler or compass
• Pencil
• Brass paper fastener
• Ballpoint pen

What you do:
• Cut two circles (1- 6 inches, 1- 4 inches), from poster board. (You can also use two small paper plates.)
• Cut a 1/2-inch-wide V-shape and a 1/2-inch-round window in one circle wheel, as shown.
• Use the pencil to poke a small hole in the center of both wheels.
• Attach the wheels with a brass paper fastener.
• Divide the circles into 26 spaces with a ruler.
• Write the alphabet A to Z on both circles.

Make a second wheel for your friend that matches yours exactly so you can write and decode secret messages.

N.B.: The cipher disk (wheel) was invented in 1467 by Leon Battista Alberti, a famous Italian philosopher and architect.
Alberti used two different alphabets located on concentric rings – this means one ring is inside of or on top of another. By lining up two different letters, one from each ring, he could make a simple substitution alphabet in which he could create a cipher.
For example, if he aligned the A on the outer ring with the G on the inner ring, this would make the following substitution alphabet used to encrypt a message:

OUTER RING: ABCDEFGHIJKLMNOPQRSTUVWXYZ
INNER RING: GHIJKLMNOPQRSTUVWXYZABCDEF

From there, he could encrypt his message and send it to someone who knew the secret to revealing the message.

Growing Celery

Growing celery cover

What you need:growing celery
• A bunch of celery
• A large, sharp knife
• A small dish or plastic container
• Fresh water

What you do:
• With a large, sharp knife, cut off the bottom of your bunch of celery about 2 inches from the base.
• Take the base of your bunch of celery and put it in a small jar or dish filled with about a half inch to an inch of water.
• Wait for a week and see what happens.

Rocket Science

Rocket Science Cover

What you need:Rocket Science
•  Unused tea bag ( We tried the black tea bag and the green tea bags, for some reason only the black tea worked for us).
• Lighter

What you do:
• Empty the tea bag of its contents. (Just take out the staple, and unfold it.)
• Open it up so that it will stand upright, as a cylinder.
• Light the top of it on fire with the lighter.
• Wait and watch.

 “Everyone knows that hot air rises and this experiment demonstrates that idea as well as the principles of convection currents. As the tea bag burns, hot air is being created, as well as a thermal, or convection current, under the bag. When the tea bag burns down into a small enough ball of ashes, the convection current causes it shoot up in the air.” 
[Quoted directly from Steve Spangler Science.]

Fun Ear Science

Fun Ear Science cover

What you need:blood flow
• Conch Shell

What you do:
• Hold a conch shell up close to your ear.

What do you hear? It sounds like the ocean. do you think an ocean is in the shell?

blood flow1No!

You are hearing your blood move through your body. Because of its shape, the shell captures the sounds of your blood moving and sends them back to the ear.

Metal Etching

Metal Etching Cover

Metal EtchingEtching -method of engraving in which lines or textures are bitten, or etched, into a metal plate, usually copper, with acid. The image produced has a spontaneity of line that comes from drawing on the plate in the same direct way as with pen or pencil on paper. The first etchings date from the early 16th century, but the basic principle had been used earlier for the decoration of armour.

What you need:Metal etching3
• Knife
• Candle
• Sewing needle
• Iodine solution
• Dropper

What you do:
• Light a candle and drop some wax on the knife.
• Put the knife over the candle so the wax melts smoothly and cover the area needed for etching.
• Let the wax cool down.
• Using the sewing needle “etch” the knife. Try to get all the way to the metal.
• Using the dropper drop the iodine solution on the scratches you made in wax.
• Let it sit a little.
• After the iodine solution becomes pale drop a little bit more.
• Let it sit for a couple of hours.
• Wash off the wax and you’ve got yourself an engraved knife.

Note: We ran the knife through the dishwasher and the engraving was still there.

Iodine Crystals

Iodine Crystals Cover

ScienceToday we are going to recreate Bernard Courtois’ experiment and get iodine crystals. But since not all of us have seaweed at home and the sulfuric acid is very dangerous we are going to use something that almost all of us already have.

What you need:
• Iodine solution
• Hydrogen peroxide
• Glass container

What you do:
• Pour a little bit of iodine solution into a glass container.
• Add few drops of hydrogen peroxide.
• Mix.

What happens:iodine crystals
• After a minute or so you will see grey iodine crystals on the bottom of the glass container.

Why:
• The Hydrogen peroxide helps to convert the iodine salts to the desired form.

Note: • Don’t try to store iodine crystals in a plastic bag, as they will  slowly turn to gas and leak through the plastic.
         • Don’t let the crystals sit out too long, they sublimate rapidly and you’ll loose them.
         • Don’t drop any of the iodine crystals on your carpet because the stain will come back for years no matter how good            you clean them. 

Iodine Science

iodine science cover

54924855_bernard_courtois01Like most other discoveries, the discovery of Iodine was a fortuitous accident. Bernard Courtois discovered Iodine in 1811. His story about the discovery of Iodine was an interesting and ironical one. While most scientists discovered something when trying to help people to save their lives, Courtois discovered Iodine when he was trying to kill people. Bernard Courtois was serving in Napoleon’s army. On account of continuous wars, Napoleon’s army required enormous quantities of gun powder. Saltpeter also spelled as salpeter (potassium nitrate – KNO3) was the principal component in gunpowder. The manufacture of potassium nitrate required potassium carbonate that is generally extracted from wood ashes. Since the sources of willow wood had nearly run out, they wanted some alternative sources of potassium carbonate.

seaweed-gatherers-1889-by-paul-gauguinAs per some suggestions, Napoleon’s army resorted to burning dried seaweed, which was found in large quantities in the coasts of Brittany and Normandy. While the Napoleon’s army was with its mission of making saltpeter, enormous quantities of sulfur compounds also evolved as byproducts. They had to add sulfuric acid to their compounds to clean them up.

iodine vaporThey said that one day the workers of the factory where Bernard Courtois was conducting his experiments ran after a cat and on the its way the cat accidentally dropped the jar with the   sulfuric acid  on the left overs of the saltpeter production which gave out a dense violet vapor cloud that got condensed onto the surfaces of colder metal objects forming highly lustrous crystals.

Courtois jumped in ecstasy at the realization that the cat had accidentally created something new. Courtois’s experimentation with this new element/compound revealed that it could combine well with a few metals, hydrogen and phosphorous, but didn’t react easily with carbon or oxygen. In addition, he discovered that the new element/compound demonstrated explosive properties on mixing with ammonia, but didn’t decompose while subjected to burning.

iodine1He had to conclude that what he accidentally created was not a compound; it was a new element, pure in form. Napoleon’s wars had emptied the government coffers. Also, there was the pressure of newer wars. Therefore, Courtois couldn’t continue with his findings. Courteous passed on his discovery to French scientists Charles-Bernard Désormes and Nicolas Clément. For some reason, Courtois had also given a sample of the new element to Louis-Joseph Gay-Lussac and André M. Ampère, who carried forward the experiment parallel to the other pair.

Iodine gets its name from the Greek word “iodes” which means “violet.”

DIY Sundial

DIY Sundial Cover

What you need:DIY Sundial
• Clay
• Pencil
• 12 Rocks
• Sun

What you do:
• Place a pencil in a ball of clay.
• Every hour mark the hour with a rock.

Naked Egg

naked egg cover

What you need:Naked Egg
• Vinegar (at least 16 ounces)
• Two glasses
• Raw egg

What you do:
• Carefully place the egg in a cup and fill the cup with vinegar so that the egg is completely covered.
• After a day of soaking you can carefully remove the egg from the vinegar.
• Depending on your particular egg, you may already have a naked egg. However, it will not hurt you fill a cup with fresh vinegar and soak the egg for at least one more day.
• After two days of soaking you should have a pretty cool Naked Egg.

HOW DOES IT WORK?

Let’s start with the bubbles you saw forming on the shell. The bubbles are carbon dioxide gas. Vinegar is an acid called acetic acid – CH3COOH – and white vinegar from the grocery store is usually about 5% acetic acid and 95% water. Egg shells are made up of calcium carbonate. The vinegar reacts with the calcium carbonate by breaking the chemical into its calcium and carbonate parts (in simplest terms). The calcium part floats around in the solution while the carbonate part reacts to form the carbon dioxide bubbles that you see.

Some of the vinegar will also sneak through, or permeate, the egg’s membrane and cause the egg to get a little bigger. This flow of a liquid from one solution through a semi-permeable membrane and into another less concentrated solution is called osmosis. That’s why the egg is even more delicate if you handle it. If you shake the egg, you can see the yolk sloshing around in the egg white. If the membrane breaks, the egg’s insides will spill out into the vinegar. Yes, you’ve made a pickled egg! Allowing the egg to react with the carbon dioxide in the air will cause the egg to harden again.