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Fun with chalk: Create your own original and fizzing chalk paint designs!

5/28/2018

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Author: Maddie Van Beek

​It’s almost summer! If you’re from the Midwest, you know that this was a LONG WINTER. It’s time to take advantage of this beautiful weather and get outside! Today, we’re going to learn a few different ways to have fun with sidewalk chalk.

 
Let’s get thinking:
  • Where do you usually see chalk?
  • What do you think chalk is made of?
  • Is chalk natural or manmade?
 
Write down your ideas and then let’s get rolling!
 
First, let’s learn a little bit about where chalk comes from. We did a blog on chalk two years ago, so we’ll dig up some information from our previous research:
Science of Chalk
History of Chalk
 
Where does chalk come from?
Did you know that chalk is actually a rock? Chalk comes from the mineral limestone, and is soft, white, and porous. The scientific name for chalk is calcite, or calcium carbonate (CaCO3).  Most of the chalk you use today is no longer made of calcium carbonate, but is instead made of a similar mineral called calcium sulfate, or gypsum.
 
Where does chalk occur in nature?
Chalk is actually mined from chalk deposits, which are found in different areas around the world such as Germany, England, and Denmark. These chalk deposits were formed over millions of years from microscopic calcite shells called coccoliths. Over time, the build-up of coccoliths created formations like the ones below!
Picture
Picture
When did humans start using chalk?
People have been using chalk for ages, as archeologists have found chalk cave drawings from early humans dated back to 40,000 BC.  Artists used chalk by grinding calcium carbonate (the chalk found in nature) and mixing it with water and pigments. Teachers commonly used chalk in the 20th century on slate blackboards. Now, we’re still using chalk for art and fun today.
 
How to make sidewalk chalk:
This is the recipe we used in our previous activity to make your own homemade sidewalk chalk. 
Picture
YOU WILL NEED:
  • Toilet paper tubes
  • Scissors
  • Duct Tape
  • Bucket or large mixing bowl
  • Wax paper
  • Water
  • Tempera paint (available at Target, Amazon, and most craft stores)
  • Plaster of Paris (gypsum)
  • Cookie sheet


Here’s what to do! 
  1. Collect about six toilet paper tubes. This is what you will use for your chalk mold. Cover one end of each tube with duct tape. Make sure the tape is secure so none of your chalk mixture will leak out the end. 
  2. Measure a 6x6 inch piece of wax paper and cut it out. Roll the wax paper square up and place it inside the unsealed end of one of your cardboard tubes. The wax paper is to keep your chalk mixture from sticking to the inside of the cardboard tube. 
  3. Repeat step 2 until you have all six of your paper tubes lined with wax paper. 
  4. Measure out 3/4 cup of warm water and pour it into your bucket. 
  5. Measure 1 1/2 cups of plaster of Paris and sprinkle it into the warm water. Stir as you sprinkle. The plaster will begin to harden in the next half hour, so you will want to work quickly. 
  6. Divide the plaster of Paris mixture into six different bowls. Pick six different colors of tempera paint, and add about 3 tablespoons of paint to each bowl. Stir until the color is evenly distributed. 
  7. Place each cardboard tube tape-side down on a cookie sheet, then pour the colored plaster of Paris mixture into each tube (one color per tube). 
  8. Move the sheet of tubes to a place where they won’t be disturbed. It will take about three days for the chalk to dry completely. Peel the tubes and wax paper off, and voila! You have your own homemade sidewalk chalk! 
  9. BONUS: To spice it up, add glitter or other materials for a fun texture! For nighttime fun, mix in a little Glow in the Dark Paint with your plaster of Paris mixture before it dries. You’ll have pictures that show up at night!
 
 
If you’re looking for a new way to experience sidewalk chalk, you can try sidewalk chalk paint! This “chalk paint” really isn’t chalk at all. Instead of gypsum, sidewalk chalk paint utilizes cornstarch.  It’s just another great way to have fun and get outside!
 
Basic Sidewalk Chalk Paint
YOU WILL NEED:
  • Cornstarch
  • Water
  • Food coloring
  • Small bowls or cups
  • Paint brushes
 
Here’s what to do!
  1. Pour a cup or so of water into the containers and add several drops of food coloring or craft paint into each.
  2. Mix about 1 cup of cornstarch into each container of water.
  3. Stir the cornstarch and water together until smooth. If it’s too thick, just add more water. A little goes a long way! If it’s way to runny, sprinkle a little more cornstarch.
  4. Paint away!
 
FIZZING Sidewalks
Now that you know how to make sidewalk chalk paint, let’s make it a little more exciting. You may have used baking soda and vinegar in other experiments. If you have, you probably know that baking soda is a base, and vinegar is an acid.
When mixed together, acids and bases cause a chemical reaction. This chemical reaction produces a gas called carbon dioxide. In this case, c02 = BUBBLES AND FIZZING FUN! Let’s try it out!
 
Here’s what to do!
  1. Follow the directions for Basic Sidewalk Chalk Paint, but sub half of the cornstarch for baking soda.
  2. Dump vinegar into a spray bottle and set aside for later.
  3. Create your sidewalk art with the sidewalk chalk paint baking soda mixture. For more abstract art, put your paint into squeeze bottles!
  4. Spray your art with vinegar and watch it bubble!
 
For more fizzing fun, check out:
Use baking soda and vinegar to blow up a balloon  
 
Make your own film canister rocket 
 
Exploding glow in the dark art



References
Blackboard chalk and whiteboard pen. History of Pencils.  http://www.historyofpencils.com/writing-instruments-history/blackboard-chalk-and-whiteboard-pen-history-and-future/
 
Chalk. https://en.wikipedia.org/wiki/Chalk
 
Chalk drawings. Encyclopedia of Art. http://www.visual-arts-cork.com/drawing/chalk-drawings.htm
 
Gypsum. https://en.wikipedia.org/wiki/Gypsum
 
Stewart, M. Magic sidewalk chalk paint. https://www.youtube.com/watch?v=bdx3Qj4zbJQ
 
Vacker, M. Homemade sidewalk chalk. PBSParents: Crafts for kids. http://www.pbs.org/parents/crafts-for-kids/homemade-sidewalk-chalk/
 
Carolyn. How to make sidewalk chalk paint. Simple Play Ideas. 
http://simpleplayideas.com/make-sidewalk-chalk-paint


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Magnets

5/24/2018

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If you take a look around you, there’s a good chance that you’ve got a magnet somewhere near you. And if it’s not in the room with you, it’s more than likely in the next room!
Picture
These fascinating objects can be anything that produces an area of magnetic force, called a magnetic field. Like most other forces, the magnetic field is invisible to the human eye. We can only see the physical effect it has on objects, like the magnetic dart board pictured above.

Magnets only affect certain metals, like iron and steel, and therefore won’t work on materials such as plastic or glass. Most refrigerator doors are made from steel sheet metal, which is what makes them excellent candidates for decorative magnets! Other metals that are not magnetic (copper, gold, or silver, to name a few) can still magnetize slightly when placed in a magnetic field.

Magnetic fields are created by the movement of electrically charged particles, such as electrons.  This movement of electrons can be a permanent quality that comes from the material the magnet is made from, like a refrigerator magnet. An example of a non-permanent magnet is an electromagnet. Electromagnets can be produced by an electric current flowing through a coiled wire. Once the electric current that creates a movement of electrons is removed, an electromagnet is no longer magnetic. To learn more about electromagnets, check out a previous blog post here!
Picture

​Every magnet has a north pole and a south pole. If the same poles of two different magnets are brought near each other, they will repel (push away from each other). But if the opposite poles are placed nearby, they will attract each other! In the picture on the left, someone has placed the same pole of two magnets near each other, and is feeling the repulsion coming from both magnets.


Magnetic objects must be inside the magnetic field in order to respond to the forces, so if you aren’t seeing the expected repulsion or attraction, you might have to move your magnets closer together.

A majority of the planets in our solar system have a significant magnetic field, including Earth! Using probes, scientists have found that Mars and Venus do not have magnetic fields, and while Jupiter has the largest magnetic field, we know that Saturn, Uranus, and Neptune’s fields are all much stronger than Earth’s.

The core of our planet is believed to be an alloy (or mixture) of iron and nickel, which is what gives off its own magnetic force. The most notable uses of this magnetic field are by compasses and birds
Picture
Picture
Birds have a special protein in their eyes that allows them to see Earth’s magnetic field. The protein is called “Cry4” and a bird can only sense the magnetism in the presence of blue light. Their “sixth sense” is especially helpful when flying long distances, as it serves as a built in compass!


Observe Magnetic Fields
Picture
Picture
By using a container with iron filings and a magnet, we can visualize the lines in a magnetic field, just like in the image above! Here’s what you’ll need.



Materials:

- Petri dish
- Tape
- Iron fillings
- Small magnet



​

Picture



​Step 1: Fill your petri dish with a small amount of iron filings. You can find a container of these filings for under $10 at a home improvement store, or by ordering online!

Step 2: Close the petri dish and tape it shut so you don’t accidentally spill the filings. Electric tape works well for this.




Step 3: Observe the magnetic field by holding your magnet against the petri dish. What happens to the iron filings when you bring the magnet closer? Try moving it around the dish and watch carefully!




Image Credits:


A, Marc. “Magnetic Dartboard”. Released into the public domain. Uploaded on 5/2/18 from publicdomainpictures.net

Kuiper, Pieter. “Feeling Magnetic Repulsion”. Released into the public domain. Uploaded on 5/2/18 from commons.wikimedia.org

Hodan, George. “Compass”. Released into the public domain. Uploaded on 5/2/18 from publicdomainpictures.net

Hodan, George. “Flying Bird”. Released into the public domain. Uploaded on 5/2/18 from publicdomainpictures.net

Black, Newton Henry. “Magnet”. Released into the public domain. Uploaded on 5/3/18 from commons.wikimedia.org

Magnet and materials images property of Discovery Express Kids, LLC.

​

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