Author: Maddie Van Beek

Once again, we are going to be using eggs to learn about science! In the past, we’ve used eggs to learn about osmosis and acid-base reactions. Today, we are focusing on sedimentation and crystallization. After you learn about these concepts, you are going to make egg geodes! 


Geode: A rock containing a cavity lined with crystals or other minerals. 

First of all, sedimentation is...

The process by which particles (solute) suspended in a fluid (solvent) eventually come to rest due to the forces, such as gravity, acting on them. 

Note:  The solute and the solvent (the particles and the liquid they are suspended in) come together to form a solution.

Crystallization is....

The process in which solid crystals precipitate from a solution or melt (Crystallization can also occur when crystals form from a gas, but this is rare. In our activity today, we are focusing on crystals that form from a solution).  

Can you think of a time that you’ve seen crystallization in the real world? I can! Back in November of last year, we did a snow blog (to see it, click here)! Snow flake formation is just one form of crystallization. Another form of crystallization is with natural crystals or gemstones. This takes a LONG TIME. 

Check out this video to see crystallization in action!

Now that you know a little bit about sedimentation and crystallization, try it out for yourself!


This is what you will be creating!

YOU WILL NEED:

• Eggs
• Push pin
• Bowl
• Small scissors
• White glue
• Small paintbrush
• Egg dye or liquid food dye
• Hot water
• Spoon
• Cup or container 
• Drying area (rack, plate, or newspaper would work fine)
  
• Alum powder--pictured below. You should be able to find Alum powder at any grocery store.

HERE’S WHAT TO DO!

1. Have you ever blown out eggs before you decorate them for Easter? That’s the first step to making egg geodes! You will need to carefully poke a hole in both the top and the bottom of the egg with the push pin. When you poke the hole, wiggle the pin around a bit to make the hole bigger. This will make it easier to blow the egg out of the shell.


2. Hold the egg over a bowl and blow on the top of the egg. The egg inside the shell should come out the bottom of the egg into the bowl. You can either throw the egg away, or go ahead and make an omelet! I suggest using your resources to have a great breakfast while you create your geodes :] 

3. This part is tricky. Now that you have an empty egg shell, you will need to use a small scissors to break the shell in half the long way. Don’t worry about it being perfect. As long as you have somewhat of a bowl shape, you are good to go. If your eggshell completely shatters, just blow out another egg and try again!


4. Again, you will have to be extremely careful in this step! Use a piece of paper towel to wipe the inside of the egg clean. Next, use the small paintbrush to coat the inside of the shell with white glue. Before the glue dries, sprinkle the Alum powder generously over the glue so that it coats the whole inside of the eggshell. 


5. WAIT!!! Your eggshell has to dry completely before you can move on. Leave it to dry overnight. 


6. Up and at ‘em? Back to the grind! Measure two cups of water and heat it up. You can either heat it to boiling on the stove or put it in a microwave-safe container and heat the water in the microwave.  Two to three minutes on HIGH should do the trick. 


7. CAREFULLY pour the heated water into the cup or container that you plan on using to create your egg geodes. 


8. Use a generous amount of food coloring to dye the water--30-40 drops is sufficient. 


9. Add 3/4 cup of Alum powder to the colored water and stir it with a spoon until the powder is completely dissolved. 


10. Let the Alum solution cool down for approximately 30 minutes. 


11. Once the solution has cooled down, use a spoon to submerge your Alum-coated eggshell. Make sure the open side is facing up, and the eggshell is resting on the bottom of the container. 


12. Now, the waiting game! Leave your eggshell to sit in the solution for 12-15 hours. Make sure you place the container in a safe place where no one will knock it over! 


13. After 12-15 hours, prepare a drying area. Use a drying rack, newspaper, or paper plate. Use a spoon to remove the eggshell from the solution.


14. Check it out! How has your eggshell transformed? Make sure to take pictures and write down your observations!


FOLLOW-UP QUESTIONS

1. What happened to your eggshell? Describe the change it went through. 
2. How can you relate your eggshell’s transformation to sedimentation and crystallization? 
3. Try to explain the process your eggshell went through. 
4. When does sedimentation and/or crystallization occur in real life? 

Here’s another fun activity about creating Alum crystals that will teach you a little more about crystallization! 

References:

• http://en.wikipedia.org/wiki/Crystallization
• http://en.wikipedia.org/wiki/Sedimentation
• http://www.marthastewart.com/343344/crystal-egg-geodes
• http://www.stevespanglerscience.com/lab/experiments/incredible-egg-geode

Author: Maddie Van Beek


Why is soap important? I’m sure you have the idea ingrained in your head that you need to wash your hands before dinner, before cooking, after using the restroom... but why?

Learn more about the importance of hand-washing in the link below!


Hand-washing Dos and Don'ts



Today, our activities are all about soap! First, we will see what happens when we put bar soap in the microwave. What do you think will happen? Next, we will try making a variety of soaps to see which ingredients do the best job of washing your hands! 

YOU WILL NEED:

• A variety of bar soaps. Pick 3-4 different brands of bar soap, but one must be Ivory. 
• Bowl
• Water
• Microwave
• Plate

HERE’S WHAT TO DO!

1. Unwrap each bar of soap. 
2. One by one, place each bar of soap in a bowl of water and record what happens.
3. Do you any of them float? Do they all sink? 
4. You should have noticed that the Ivory bar floats. Why is it that Ivory floats while others sink? Make a hypothesis!
5. You might have guessed that there was an air pocket in the Ivory soap... cut it open and find out.
6. Did you find an air pocket? Nope! What could it be? 

Explanation: The truth is, Ivory soap IS filled with air, but only in minuscule amounts. There are no large air pockets, but there are tons of tiny little air bubbles whipped into the soap during production. These little air bubbles are what make Ivory soap float. 


Now, let’s see what happens when we put Ivory soap in the microwave!


HERE’S WHAT TO DO!

1. Place the Ivory soap on a paper towel in the microwave.
2. Set the microwave on HIGH for 2 minutes.
3. Observe amazingness! What happened?!
4. You should have seen the Ivory soap expand much like a marshmallow! Why do you think this happened? Clue: Think about the air bubbles. 
5. This effect is actually a demonstration of Charles’ Law. Charles’ Law states that volume of gas will increase as temperature increases. How did you see that demonstrated when you put the Ivory soap in the microwave? Explain how your observations relate to Charles’ Law. Learn more about Charles’ Law HERE. 

Here’s video that demonstrates what should have happened:

Let’s switch gears--we are now going to make our own soap! Rather than making entirely homemade soap, we are going to take a quick shortcut that will allow you to alter plain bar soap and compare the additives that you choose to use. 

YOU WILL NEED:

• Bar soap
• Spoon
• Small microwavable bowl
• Muffin tin
• Masking tape
• Marker
• Additives of your choice--could include milk, honey, oatmeal, sugar, cinnamon, etc. 

HERE'S WHAT TO DO!

1. First, you need to buy a few bars of fragrance free, dye free soap. 
2. Next, decide which ingredients you would like to add to your soap. A common combination is milk and honey. You could also try using oatmeal or sugar as an exfoliant. You decide! How might adding these ingredients affect the soap’s hand-washing effectiveness? Write down your hypotheses for each combination you create. 
3. Next, you will melt the bar soap down to a liquid form. Be careful--it does get very hot when melted! Stop the microwave every 30 seconds and stir until the soap is completely melted. 
4. Mix in your additives with the melted bar soap. Make sure you save one piece of bar soap to use as a control. 
5. Pour the bar soap mixture into a muffin tin. Make sure you label the tin with masking tape and a marker so you know which soap is which. For example, you might label the row, “Honey Oatmeal,” “Honey Milk,” or “Cinnamon Sugar” depending on what you mixed with your soap.
6. Let the soap dry completely. This will take a few hours.
7. Now that your soap is finished, try it out!
8. Find a few friends to help you determine which soap is most effective. Use a washable marker to draw a line on your friends’ hands. Have each of them use a different soap for 1 minute. Record observations. Which soap washed the marker off most completely? 
9. Repeat step 7, except have each friend use a different soap than the one before. Did you get the same results?
10. Repeat step 7, except have each friend use a different soap than the last two times. Did you get the same results? Continue until each friend has used each soap, including the original, unchanged bar soap. 
11. Repeat steps 7-9, except use permanent marker. Did you find the same results?
12. Repeat steps 7-9, except use pen. Did you find the same results? 
13. Create a table or graph to represent which soap was most effective in removing the marker, permanent marker, and pen.  

Check out our Clean Hands Challenge for another fun experiment about hand-washing! 








Resources:

http://www.stevespanglerscience.com/lab/experiments/soap-souffle

http://www.chm.davidson.edu/vce/gaslaws/charleslaw.html

http://www.wikihow.com/Make-%27Melt-and-Pour%27-Soap

http://www.education.com/activity/article/Make_Soap_middle/

Author: Maddie Van Beek

Before we get going, think about these questions: How often do you watch the weather on TV? What kind of weather conditions have you seen reported? What kinds of weather conditions have you experienced in your lifetime? How has weather impacted your life? 


Get your brain warmed up! Write about a specific weather memory. 


Make a connection: Why would you need to pay attention to the weather? Can you think of a time that knowing the approaching weather would be important? 


Predict: Before you read ahead, hypothesize what do you think creates or influences weather conditions. Write down any guesses you think of! 


When you were thinking of what might influence or change the weather, did you ever think of air masses? Air masses are extremely important to consider when predicting what the weather may be like! 


According to education.com, an air mass is a large body of air with consistent temperature and humidity. When air masses form, they are taking on the temperature and humidity characteristics of the region they are in. The density of an air mass depends on the temperature and humidity levels. Warm or humid air masses are less dense then cold or dry air masses. 

Does it surprise you that humid air is less dense than dry air? 

This is because a molecule of water has a smaller mass than a molecule of oxygen or nitrogen (a large percentage of dry air molecules are nitrogen). 

But what happens when two different air masses meet? That’s our focus today! Think of oil and water as two separate air masses. If oil represented the warm air mass and water represented the cold air mass, what would you see happen? A boundary would form between the oil and water, and the oil (warm air) would float above the water (cold air). 

Here’s a little more information about fronts:

“Vilhelm Bjerknes (1862-1951), a Norwegian physicist and meteorologist, coined the term front to describe the boundary between warm and cold air masses. The leading edge of a warm air mass advancing into a region occupied by a cold air mass is called a warm front. A cold front occurs when a cold air mass advances into a region occupied by a warm air mass. If the boundary between the cold and warm air masses doesn't move, it is called a stationary front. The boundary where a cold air mass meets a cool air mass under a warm air mass is called an occluded front. At a front, the weather is usually unsettled and stormy, and precipitation is common." 

Here is a visual to help you understand the difference in air movement during cold fronts and warm fronts:

Analyze the visual and explain what you see.

As the warm front approaches, there may be fog or increasing rainfall, and thunderstorms may form, as well. This is due to the (usually) higher humidity in the air of warm fronts compared to that of cold fronts. Because warm air is less dense than cold air, the warm air rises as it runs into the cold air, which is followed by condensation and cloud-forming. 

Similar events happen when a cold front encounters a warm front, except they happen more quickly. Because cold air is denser than warm air, cold fronts are able to force warm air out more quickly. The cold air pushes the warm air upwards, which may be followed by precipitation or storms due to moisture in the air. 

Don’t quite get it? Try out this air mass activity to help you better understand air masses before we move on! 

Air Mass Activity

Check out this video to see a demonstration similar to the activity we will do next!

Here’s another similar example. Think about how this demonstration is similar to the one we already watched. What did these experiments have in common? What are they demonstrating? How are the demonstrations different? Do the differences show us different things, or are they basically two different ways to show use the same concept? Explain. 

Let’s try this on our own! 

Our task today, using food-colored cold and hot water as a visual, is to find out what happens when a warm front and a cold front collide. 

Hypothesize: What do you think will happen when you combine warm water and cold water? Will they mix immediately? If not, how long do you think it will take to mix? 


YOU WILL NEED:

• Writing utensil
• Paper
• Blue crayon or marker
• Red crayon or marker
• 10-gallon aquarium or container
• Piece of cardboard
• Scissors
• A large spoon
• Five gallons of very cold water (you may refrigerate the water in advance or put it in the freezer to chill it) 
• Blue and red food coloring
• Five gallons of very hot water (you may use the stove or microwave to heat the water, but ask an adult for help) 
• Timer 

HERE’S WHAT TO DO!
1. Before we start the demonstration, use a writing utensil to draw seven pictures of the aquarium we will be using. Label the pictures 0 minutes, 1 minute, 3 minutes, 5 minutes, 7 minutes, 10 minutes, and 15 minutes. You will be using these rectangles to create visuals of what you see for the next 15 minutes.

2. Measure the tank’s width and height, and then use those measurements to cut a piece of cardboard of identical measurements. Use the ruler to draw a straight line where you will cut the cardboard in order to make sure your piece of cardboard is cut as exactly as possible. 

3. Place the piece of cardboard in the middle of the aquarium so that it fits snugly and can stand on its own. From an aerial view, you would see something like this:

4. Make sure the cardboard fits snugly, as it needs to keep water from passing through the center of the aquarium for at least one minute! 

5. Next, grab your container of cold water and your container of hot water. Color your cold water with blue food coloring and your hot water with red food coloring. Add the desired amount of food coloring to the water and mix in with a large spoon. 

6. Once the water is colored, the cardboard is in place, and you have your drawings ready, fill the left side of the tank with the cold, blue water.

7. Now, fill the right side of the tank with the hot, red water.  

8. Remember, the blue water represents a cold air mass and the red water represents a warm air mass. 

9. Using the drawing labeled 0 minutes and the red and blue markers, sketch what the tank looks like right now. Do this quickly--it does not have to be perfect. 

10. Finally, carefully remove the cardboard from the tank and start your stopwatch. 

11. Using your pre-labeled drawings, sketch what the tank looks like at 1, 3, 5, 7, 10, and 15 minutes.
 
12. Organize your pictures in chronological order and analyze the sequence. What happened initially when you removed the cardboard barrier? What happened as time went on? Did the “air masses” stay side by side, or did they shift? Describe the movement. Explain the behavior you observed. 


Extension: Create captions that describe what is happening for each visual you created. 


YOU SHOULD KNOW: 

What is an air mass?

What is a cold front?

What is a warm front? 

What happens when two air masses collide? 





References: 

http://ww2010.atmos.uiuc.edu/(Gh)/guides/crclm/act/arms.rxml

http://sciencenetlinks.com/lessons/air-masses/

http://www.education.com/science-fair/article/when-air-masses-collide/

http://www.education.com/science-fair/article/fronts-moving-air-masses/

http://en.wikipedia.org/wiki/Cold_front

http://en.wikipedia.org/wiki/Warm_front

http://en.wikipedia.org/wiki/Humidity