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When a substance is heated it’s molecules move faster. You can see this in a pot of water when you heat it on the stove. As the water gets hotter its molecules begin to move until the water is boiling.

When gases are heated, the same thing happens. As gas is heated up the amount of space the gas takes up increases. You can see this by heating up a bar of soap.

You have to use a bar of soap that floats. To make sure you have a bar of soap that will work, float it in a bowl of water. A bar of soap will float because it has air bubble whipped into it. Ivory soap will work for this experiment.

What You Need:
Bar of Soap that Floats
Bowl of Water
Paper Plate
Microwave

Break or cut the bar of soap into four pieces. Put the pieces on a paper plate and microwave for 1 minute. Watch the ivory soap through the microwave window.

As you heat the soap molecules in the air bubbles move quickly away from each other, or expand. This is called Charles’s Law. The same thing happens when you pop popcorn or cook a marshmallow .

Sciece Experiment Idea: Choose different kinds of soap to see what will happen when they are heated up for one minute in the microwave. Be sure to heat each bar of soap up on the same kind of plate and make sure you heat each bar for the same amount of time. The variable in this experiment is the soap, everything else has to be the same. Do the bars of soap each react the same way when they are heated up in the microwave? Why do you think so? Tip: Choose ivory soap for one of your trials – it’s cool!

Here are some books that will help you learn about and experiment with heated gases:

• Encyclopedia Britannica Kids: Heated Air Expands
• Naked Eggs and Flying Potatoes: Soap Souffle  (pages 48-51)
• Kitchen Science Experiments: The Great Growing Marshmallow (pages 55-56)
• Science Experiments That Explode and Implode: Slow Motion Explosion (pages 8-9)
• Super Simple Things To Do With Pressure: Microwave Magic (pages 21-22)

Words to Know:

Atoms - The smallest, most basic unit of matter. An atom is made up of a nucleus surrounded by electrons.
Molecules - At least two atoms held together by a chemical bond.
Charles’s Law – as temperatures of a gas increase, so does its volume. Simply, heated gases expand.
Heat – to make hot or warm.

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In today’s experiment you will see how materials that have different density behave when they are put in the same jar or glass. Density  is how close together the molecules of a substance are or how much mass a substance has in a given space. If you have one cup of jelly beans and one cup of marshmallows…the jelly beans have more mass…there is more “stuff” compacted into the cup. The marshmallows are mostly air. If you put each of those cups in a microwave to melt…the sugar and water that makes up the jelly beans would almost fill the cup to the top. The sugar and water that makes up the marshmallows would only fill the cup a little bit because marshmallows have less mass, they are mostly made of air. Materials with more density weigh more. A cup of jelly beans weighs more than a cup of marshmallows.

If you pour several materials of varying density in a jar, the materials with more density are heavier and will sink to the bottom. Watch this happen be putting several household materials in a jar. If you use materials that are different colors you will see layers in the jar.

You Will Need:

• Tall Jar or Glass

1. Honey
2. Light Corn Syrup w/ red food coloring in it
3. Blue Dish Soap
4. Water w/green food coloring in it
5. Vegetable oil
6. Rubbing Alcohol

Slowly pour a layer of each substance in the glass jar. Try to be pour carefully so that there are no smudges on the sides of the jar. Pour the substances in order 1-6. Once you are done and have observed the layers, put a lid on the jar and give it a couple shakes. How do the layers look now? Let the jar sit for an hour. Now how do the layers look?

Science Experiment Idea:

Gather five small glass containers – small jars or glasses…baby food jars would be perfect. Carefully fill the first container halfway with honey, the second container halfway with light corn syrup (w/red food coloring in it), the third container halfway with blue dish soap, the fourth container halfway with vegetable oil and the last container halfway with rubbing alcohol. Now fill a small pitcher water and add green food coloring to it. Use the green water to fill up each jar to the top.

For each substance, guess whether it will be more or less dense than water. Will the water stay on top or will it form a layer below? Materials with more density weigh more. Any substance that has more density than water will remain the bottom layer. Any substance with less density than water will rise to the top.

Here are some websites with more density information and experiments:

• Fetch Potion Commotion
• ZOOM Activity: Water Density
• Activity TV: Double Density
• Virtual Mass, Volume and Density Lab

Here are some books that help you learn about density with layering demonstrations like this one.

• How to Make a Liquid Rainbow
• Science Experiments That Surprise and Delight “Layer Magic” (pages 26-27)
• Science Rocks “Liquid Layers”

Words to Know:

Density – How closely packed together the molecules of a substance are.
Mass - How much matter fits in a given space.
Matter - Stuff
Weight - A measure of the force of gravity on an object. Materials with more density weigh more.
Volume – How much space a substance takes up.
*****The confusing relationship between weight and mass: On earth, a bowling ball can weigh about 10 pounds. If you take that same bowling ball to the moon it will weigh much less because the graviational pull of the moon is less than the gravitational pull on the earth. Weight is a measure of gravitational pull. So the weight of the bowling ball, or anything else, changes depending on where you weigh it. The mass of the bowling bowl does not change no matter where it is. The bowling ball has the same amount of mass  on earth as it does on the moon or anywhere else you take it.

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Everything in the universe is made of teeny tiny particles called atoms. Some things are made up of just one kind of atom. A penny is made up entirely of copper atoms. Atoms can join together to make molecules. When penny is exposed to oxygen in the air, the copper atoms of the penny and the oxygen atoms in the air combine, a chemical reaction takes place that make a molecule called copper oxide – that is the dirty stuff that you see on the penny.  This “stuff” is often referred to as “tarnish.” When you soak the pennies in taco sauce, another chemical reaction takes place. Try this experiment to watch this chemical reaction.

You Will Need:

• Dirty Pennies
• Taco Sauce
• Vinegar
• Tomato Paste
• Salt
• Water
• Small Plates
• Masking Tape

Put some tarnished pennies in a small dish and pour taco sauce over them. Let the taco sauce sit for a few minutes and then wash the taco sauce off the pennies. How do the pennies look now? If you look at the ingredients in the taco sauce you will notice that the main ingredients are tomato paste, vinegar and salt. Which ingredient affected the tarnish on the pennies? To find out, you need to test different combinations of the ingredients. First, try to polish the pennies with just tomato paste, just salt and just vinegar. How do the pennies look? Then, try polishing the pennies in different combinations of the ingredients: tomato paste + salt, vinegar + salt and tomato paste + vinegar.  Which combination worked best?

Here are some websites that will give you good directions for this experiment and an explanation of the chemical reaction that creates the tarnish and then takes it away again:

• Exploratorium: Copper Caper
• PBS Kids: Fetch Copper Cleanup

Here are some books that will help you see other chemical reactions that polish tarnish from pennies or silver.

• Google Preview – Science Experiments That Surprise and Delight: Taco Sauce Penny Cleaner (pages 60-63)
• Science Rocks!: Spruce Up Silver (pages 41-42)
• Google Preview -  Science Experiments That Fizz and Bubble: Not Quite the Midas Touch (Pages 20-21)
• Mythbusters Science Fair Book – Can Cola Shine a Penny? (Pages 13-14).

Words to Know:

Chemical Reaction – A change in which a substance (or substances) is changed into one or more new substances.

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Sometimes when atoms come together to form a molecule, one end of the molecule has a positive charge and one end of the molecule has a negative charge. When this happens the molecule is a polar molecule. Molecules that do not have two electrical poles are called non-polar molecules.

This experiment will  show you how polar molecules and non-polar molecules behave when added together. If two kinds of molecules are added together that are both polar molecules, they will mix. They are miscible. Miscible means that the two things can mix together. If two non-polar molecules are added together they will also mix and are miscible. However, if a non-polar molecule and a polar molecule are added together, they will not mix together. This is called imiscible. Imiscible means that the two kinds of molecules CANNOT mix together.

What You Need:

• Plastic Bottle
• Water
• Vegetable Oil
• Food coloring
• Measuring Cups
• Alka Seltzer

Fill the bottle about 3/4 of the way up with vegetable oil. Fill the bottle the rest of the way up with water. Now add some drops of food coloring. Close the cap on the bottle and shake it up. What happens?

Break the alka seltzer tablet in half. Open the bottle and drop in one half. What happens? Once the bubbles settle down drop in the other half. What happens again?

Water is a polar molecule. Vegetable oil is a non-polar molecule. These two substances do not mix together, they are imiscible (they will not mix together). That’s why you see the blobs of water bobbing around in the oil. Food coloring is a polar molecule so it WILL mix with the water. The water and the food coloring are both polar molecules will mix together. That’s why the water blobs turn the color of the food coloring and the oil does not.

The alka seltzer just makes the bottle more fun because it makes the colorful water blobs move without shaking the bottle. The alka seltzer tablets dissolve in the the water and make carbon dioxide gas (like we saw vinegar and baking soda do in the Exploding Ziploc experiment). The carbon dioxide gas bubbles attach to the colorful water blobs and make them float to the top of the bottle. When the gas bubbles pop there is no gas bubble to hold up the water blob, so it slowly floats back down to the bottom of the bottle.

Here are some website and books that will give you good directions for making your own lava bottle and understanding molecules and polarity:

• National Geographic for Kids: Groovy Lava Lamp
• Steve Spangler Science: Make Your Own Lava Lamp
• Science Bob: Blobs in a Bottle
• Exploratorium: Glitter Globe
• Glasgow Sciece Center: Lava Lamp
• Science Rocks! Fizzy Fountain (pages 24-25)
• Naked Eggs and Flying Potatoes: Bubbling Lava Bottle (pages 36-39
• Super Simple Wthings To Do With Bubbles: That’s Lava-ly! (pages 16-17)

Science Experiment Idea: Make several different lava lamps using different liquids for the water. Try vegetable oil and water, like our experiment today. Then try vegetable oil and rubbing alcohol or vegetable oil and orange juice or vegetable oil and olive oil. See if you can determine which substances are miscible when added together. Which ones make a good lava lamp and which ones don’t?

Words to Know:

Polarity – When atoms align.
Atoms - The smallest, most basic unit of matter. An atom is made up of a nucleus surrounded by electrons.
Molecules - At least two atoms held together by a chemical bond.
Polar Molecule - A molecule that has two opposite electrical poles. One end of the molecule has a positive charge and one end of the molecule has a negative charge.
Non-Polar Molecule – A molecule that does not have opposite electrical poles.
Miscible – Able to mix when added together.
Imiscible – Not able to mix when added together.

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