Author: Maddie Van Beek

Happy Thanksgiving! Just a few days ago, most of the country was celebrating Thanksgiving by having a turkey dinner. Traditionally, Thanksgiving dinners aren’t complete without mashed potatoes and gravy, but gravy is notoriously tricky to thicken to the right consistency. So how exactly do you make gravy, anyway? Let’s find out! ​

Author: Maddie Van Beek

Today, we are going to create a fun and foamy reaction that looks like a tube of toothpaste big enough for an elephant! You've created other reactions in the past, such as when we exploded a plastic bag or created film canister rockets. The most similar reaction to the one we are creating today is when we blew up a balloon with yeast. Yeast is going to be part of our reaction today. ​

If you missed our other ultra-reactive blogs, check them out here: ​

What are chemical reactions? In a chemical reaction, two or more molecules interact, which causes a change in the molecules. Old bonds are broken and new ones are formed. 


Learn more about chemical reactions here: http://www.chem4kids.com/files/react_intro.html


There are more than one type of chemical reaction. An exothermic reaction releases heat or light. An example of this is wood burning in a fire. The wood burning releases heat and light. This is the opposite of an endothermic reaction. While an exothermic reaction releases energy, an endothermic reaction absorbs it. Today, you are going to be creating an exothermic reaction.


In order to create Elephant Toothpaste, you will use a catalyst to get the reaction going. A catalyst increases the rate of a chemical reaction. ​

In this activity, yeast is your catalyst. When the yeast meets the hydrogen peroxide, it will cause the peroxide to quickly release oxygen.  ​

The oxygen is released in the form of a bunch of tiny bubbles, thus creating foam that looks like toothpaste!
Vocab to remember:

• Reaction
• Exothermic 
• Endothermic
• Catalyst

Check out this amped-up version of Elephant's Toothpaste on Jimmy Kimmel. ​

Author: Maddie Van Beek

Today, we are going to mix together a few different substances to create a new substance of a different color! I know this sounds like common sense... when you mix together certain colors, they create a new color. For example, if I mixed together a red liquid and a yellow liquid, the result would be an orange liquid. But today is a little different! We are going to mix together a few substances–different substances that will cause a clear liquid to suddenly change blue! Don’t believe it’s possible? Let’s get going!


Before we move on to the activity, you must understand the reaction that will occur. The reason that your liquid will turn from clear to blue is because the substances involved cause a chemical reaction. That reaction makes all the difference! Otherwise, there would be NO WAY that two clear liquids would make blue! (For a review of chemical reactions, visit our blog about the reaction between vinegar and baking soda).



The reaction that we are working with today is called an Iodine Clock Reaction. You will be using iodine, starch, and Vitamin C to create this reaction. The starch is trying to turn the iodine blue, but the Vitamin C is battling the starch. This causes a delay in the reaction. Eventually, the starch defeats the Vitamin C and the color change occurs.

The delay is the reason it’s called a clock reaction. Initially, when the two liquids are mixed, nothing happens. It takes a certain amount of time for the reaction to occur, and then BAM! Your liquid will suddenly change colors!


Check out this video of the reaction that you will be creating:

YOU WILL NEED:
* Iodine tincture (2% from the pharmacy)
* Vitamin C tablet (1000 mg)
* Hydrogen peroxide (3% from the pharmacy)
* Liquid laundry starch
* 3 clear plastic cups
* Measuring spoons and measuring cups


Here’s what to do!
1. Label your cups A, B, and C.
2. Put a 1000mg Vitamin C tablet into a plastic bag and crush it up. You could use any hard object to help you crush it into a fine powder.
3. Carefully dump your Vitamin C powder into cup A. Add 2 ounces of warm water into the cup and stir until the powder is dissolved. Observe: What color is liquid A? What does it look like?
4. Before the next step, take a look at the iodine. What color is it?
5. Put one tablespoon of liquid A into the cup labeled B. Add one teaspoon of iodine. What happens to the color when these two liquids are mixed together? Set cup A aside.
6. Put 2 ounces of warm water into the cup labeled C. Add one tablespoon of hydrogen peroxide, then add 1/2 teaspoon of liquid starch. Use a spoon to stir the liquids together.
7. Now, let’s get going with this chemical reaction! Carefully pour the liquid in cup B into cup C. Pour the liquid back and forth between the two cups a few times and then wait patiently for a chemical color-changing surprise!


Extension: You just demonstrated an iodine clock reaction. How can you add a variable to create an experiment? Try changing the temperature of the water or the amount of Vitamin C or iodine to see if this affects the time it takes for the liquid to change colors! What about mixing? If you just let the liquid sit after you mix them, does it take longer to change? If you stir it more, does it change faster? Make sure to record your observations!


References:
https://en.wikipedia.org/wiki/Iodine_clock_reaction
https://sciencebob.com/rapid-color-changing-chemistry/

Author: Maddie Van Beek

You may have heard the saying “oil and water don’t mix.” It’s true! If you’ve never seen oil and water together in the same container, you will soon! The reason oil and water don’t mix is because they have different densities. Oil is less dense than water, which means that it weighs less. Because water is more dense, it sinks to the bottom of the container. Because oil is less dense, it will always float to the surface of the water.
​
Test it out!

Fill an empty water bottle about three-fourths full with water. Add about a half-cup of oil to the bottle. What happens? The oil just sits right on the surface. Tip the bottle upside-down. The oil rises to the top and the water sinks to the bottom. What do you think will happen when you shake up the bottle? Try it out! It may look like the oil and water have mixed, but it’s only temporary. You probably see that the bottle looks to be filled with a bunch of bubbles. This is the oil broken up by the vigorous shaking. Eventually, all the oil will rise back to the top.


We took this demonstration a step further a few weeks ago when we made our own lava lamps out of colored water and vegetable oil: http://discoveryexpress.weebly.com/blog/make-your-own-lava-lamp.


You just saw a small example of how oil is insoluble in water. Insoluble means that the oil does not dissolve or mix in with water. Why would this matter in real life? Oil is a commodity that is always being shipped across the ocean to different areas. Sometimes, there are mistakes and oil is spilled into the ocean, possibly because of a leak in an oil tanker. Why would this matter? While oil sits on top of the water because it’s insoluble, it is extremely difficult to remove from the water. That’s what we are going to focus on today!


Check out this link to learn more about oil spills and why they are a BIG DEAL: http://www.kidzworld.com/article/24170-oil-spills-sad-but-true


How do we deal with oil spills? Read this article about how oil is removed from water: http://www.livescience.com/32524-how-are-oil-spills-cleaned.html


The question of the day: What is the most effective way to remove oil from water? In this experiment, you will use different materials to act as surface skimmers, the first of the four oil spill cleanup methods you just read about on livescience.com.


YOU WILL NEED:

• Water
• Vegetable oil
• Clear container
• Dry-erase marker
• Tools: Cotton balls, gauze, polypropylene cloth

Here’s what to do!
1. Fill your clear container half full with water.
2. Add vegetable oil to the container of water until you have at least a half-inch layer of oil sitting on the top. This is your oil slick.
3. Use a dry-erase marker to mark the where the surface of the oil is. This is your reference point to see how much oil you can remove with your materials.
4. Make a prediction about which tool will work best for removing the oil from the water. Why do you think this will work the best?
5. Make a chart to record your observations. It may look something like this:

Author: Maddie Van Beek

Halloween may be over, but that doesn’t mean you can’t still have some spooky fun with Halloween science activities! 


1. Use your colorful candy to try out candy chromatography! 


What exactly is chromatography? 


Chroma means color and graphein means to write. 


There are a few different kinds of chromatography, but today you are going to be dealing with paper chromatography. When you use paper chromatography, you can separate different inks or dyes into their individual components. For example, a black marker actually has many different colors of dye to create black ink.

​Watch the video below to watch how paper chromatography can be used to separate black ink into its individual colors: 

You can use this same idea to separate the dyes of your favorite candies! 


YOU WILL NEED

• M&Ms or Skittles
• Coffee filter paper
• A tall glass 
• Water 
• Table salt 
• Pencil
• Scissors
• Ruler 
• 6 toothpicks 
• Aluminum foil 
• 2 liter bottle with cap

Check out our blog about candy chromatography here for instructions: http://discoveryexpress.weebly.com/blog/candy-chromatography


2. Create your own glowing beverages! 


Did you know that tonic water glows under a black light? The reason that it does this is because of one special ingredient: quinine. 


Why is quinine fluorescent? Read the link below to find out! 

Now that you know about quinine, do you know what a black light is? Why is a black light any different from a regular light? They might appear the same as any other light bulb, but they function very differently. Black lights actually produce ultraviolet light. When you turn a black light on, it causes white things to glow in the dark. 


Read about black lights in the link below to find out how they work: ​

YOU WILL NEED

• Tonic water
• Ice cube trays
• Sprite or 7-up
• A black light

​
Here’s what to do! 


The instructions for this activity are very simple. Make ice cubes out of tonic water and then put them in any light colored drink such as 7-up or Sprite. Turn on a black light, turn off the lights, and watch your beverages glow an eery blue!


3. Make pumpkin slime!


The slime that you will be creating is a non-newtonian fluid. Newtonian fluids behave as you would expect a liquid to behave. For example, when you hit water, it gives way. You can easily put your hand through it without much resistance. Non-newtonian fluids sometimes act like a solid and sometimes act like a liquid. When you hit a non-newtonian fluid, it resists the impact. How can that be? 


Watch this video to see people experiment with non-newtonian fluid. They even try to bike across it! You’ll be amazed at its power to resist stress. ​

YOU WILL NEED:

• One pumpkin
• Cornstarch 
• Mixing bowl
• Spoon
• Cookie sheet or pan
• Food coloring (optional: your pumpkin will already color your slime an orangey tint)

Check out our blog from a few weeks ago to learn more about non-newtonian fluids and create your own pumpkin slime: http://discoveryexpress.weebly.com/blog/pumpkin-slime




References:
https://sciencebob.com/free-halloween-science-ideas/


http://www.scientificamerican.com/article/shining-science-explore-glow-in-the-dark-water/


http://science.howstuffworks.com/innovation/everyday-innovations/black-light.htm