Category Archives: Science Experiments

Miscible Molecules: Lava Bottle

Miscible Molecules: Lava Bottle

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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:srpalkaseltzerdog

  • 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:

Science Rocks Naked Eggs and Flying Potatoes Super Simple Things To Do With Bubbles Atoms and Molecules

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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Transpiration – Flower Transformation

Transpiration – Flower Transformation

srpcarnationFind More Science Experiments Plant parts like petals, leaves and stems have little holes called stomata – kind of like the pores in our skin. When stomata open, water escapes. When this happens the water is replaced by the plant absorbing water up from the roots into the stem and leaves and petals. As water evaporates from the leaves and petals more water is sucked up through the stem from the roots. This is called tranpiration…kind of like a person sucking on a straw. What You Need:

  • White Flowers (Carnation, Queen Anne’s Lace)
  • Food Coloring
  • Water
  • Vase

Fill a vase with water. Add food coloring to the water. Collect or buy some white flowers. Make a fresh cut at the end of the flower stem and put the flowers in the water. Check on the flowers every hour. How are the petals changing?

Mythbusters Science Fair Book Super Simple Things To Do With Plants Eyewitness Plant

Words to Know: Cohesion – When molecules of the same substance stick together. Transpiration – The loss of water from the parts of plants; petals, leaves, stems, flowers, etc. Absorb -  To soak up. Evaporation – Water changing from a liquid to a vapor.

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Air Pressure – Do Not Open Bottle

Air Pressure – Do Not Open Bottle

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srpwaterbottleEven though air seems like nothing, it really is something. Gases like air, even though they are not visible to our eyes, are made up of molecules just like solid objects. These molecules are pulled toward the earth by gravity.

Earth is surrounded by a layer of air that is heavy. That layer of air exerts pressure on the surface of the earth, a lot of pressure. Our bodies are used to it so it doesn’t bother us. In fact, we are so used to it that what bothers us is when the air pressure is gone.

The higher you go in the atmosphere, the less air pressure there is because the “thickness” of the air is less the higher you go. That’s why airplanes have “pressurized” cabins. We can’t survive in too little air pressure.

What You Need:

  • Empty Water Bottle
  • Thumb Tack
  • Water

As the bottle is filled with water the water pushes any air left in the bottle out. When you put the lid on no air can get in the botter either. Air on the outside of the bottle is pushing on it as well as the lid. The small holes in the bootle aren’t big enough for air to sneak in and increase the air pressure on the water…but when you open the cap more air can get in and press down on the water making it leak out the holes.

Here are some websites and books that will help you understand air pressure:

That Surprise and Delight Naked Eggs and Flying Potatoes Super Simple Things to Do With Water

Words to Know:

Air Pressure – The force that air exerts due to it’s weight. Even though air seems like nothing, it really is something. Gases like air, even though they are not visible to our eyes, are made up of molecules just like solid objects.

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Sound Waves – Salt Sound Meter

Sound Waves – Salt Sound Meter

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Sound is vibrations that move through the air or through liquids or solids. The sounds we usually hear are vibrations that move through the air. Your voice is the vibration of your vocal chords. The tiny bones inside your ears pick up sound vibrations in the air and send those messages to your brain. You can actually see sound…if you know how to look.

srpwhistleWhat You Need:

  • Large Bowl
  • Plastic Wrap
  • Salt
  • Water
  • a Whistle
  • 2 Large Metal Pans
  • Anything That Makes Noise!

Stretch a large piece of plastic wrap over a bowl and pull it tight on all the edges. Sprinkle salt on top of the plastic wrap. Now blow a whistle or clap your hands or bang two objects together – how does the salt behave? Now clean the salt off and try putting drops of water on top of the plastic wrap. Can you make the water move with sound?

Science Experiment Idea:

Try different noisemakers to see which one will move the salt the most. Make marks on the platic wrap with a sharpie to help you see how much the salt moves. Try different volumes of sound both loud and soft as well as high and low pitches. For example, can you hum and make the salt move? Can you scream and make the salt move? How about a kazoo? A whistle? Which kind of sound do you think will move the salt the most? After testing, were you right?

Light and Sound Loud or soft? high or low? : a look at sound Listen Learn about Sound The Science of a Guitar

Words to Know:

Sound – Vibrations that travel through a solid, liquid or gas.
Volume - The loudness of sound.
Pitch – How high or how low a sound is.

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Make a Kaleidoscope

Make a Kaleidoscope

srpkaleidoscopeFind More Science Experiments

Many of you have probably played with a kaleidoscope. It is a tube that you hold up to your eye. You point the tube toward light and then slowly turn it. As you turn the tube you can see patterns of colors at the other end of the tube. A kaleidoscope works by reflecting light.

Light travels in a straight line. When light bumps into something it changes direction. If light bumps into something shiny it reflects back in the direction it came from. Think of light like a bouning ball. In a kaleidoscope there are shiny surfaces. If you make your own kaleidoscope you can use mirrors or aluminum foil. When you point the kaleidscope toward light, the light enters the kaleidoscope and reflects back and forth between the shiny surfaces inside the kaleidoscope. Since you have filled the end of the kaleidoscope with little shiny objects, the light bounces off those too and makes the interesting patterns of color. As you turn the kaleidoscope the little shiny objects move which makes the patterns of color move.

Here is a video that will show you how to make your own kaleidoscope:

Here are some websites and books that will help you understand how kaleidoscopes work or build your own:

Stomp Rockets, Catapults & Kaleidoscopes
Build Your Own Mini Golf Course (Kaleidoscope page 18)

Stomp Rockets Catapults and Kaleidoscopes Build Your Own Light and Sound Tricks of Light and Sound

Words to Know:

Reflect: To bounce off.

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