STEAM

Materials:

Quart sized plastic baggies

Number 2 pencils (pre-sharpened)

A large plastic bin (if you’re doing the experiment indoors)

Instructions:

1. Fill the plastic bags with water and seal them tightly.

2. Take the bags outdoors or hold them over the bin.

3. Predict what will happen when you put the pencil through the bag.

4. Quickly pierce both sides of the bag with the pencil. If you take too long, the bag will leak. The pencil should go through the bag, but the bag shouldn’t leak.

5. Predict what will happen when you remove the pencil.

6. Remove the pencils.

Experiment Variations:

Try sticking other objects through the bag (like crayons or bamboo skewers) to see which one produces the least amount of leaks. You can also test the activity with other types of materials. Try using a cloth bag, a different kind of plastic, or a paper bag. Does the same thing happen?

Data Recording and Analysis:

“All good scientists know that data recording and analysis is crucial to any scientific discovery” (Easy! 3 Steps to the  Perfect Leak Proof Bag Science Experiment). This will look different depending on the grade level of the child. A young child might draw a picture of the results and write a word or two. (Easy! 3 Steps to the  Perfect Leak Proof Bag Science Experiment)

Science behind the lesson:

“Plastic baggies are flexible because they contain long chains of molecules that can bend and flex. If plastic bags did not have polymer chains, the plastic would be hard and inflexible. But, because these chains are so flexible, when you pierce the bag, the molecular chains in the plastic flex around the pencil inside the hole, creating a tight seal around the pencil and preventing the water from escaping (although you may have a few minor leaks). When you remove the pencils, the polymer chains can’t move enough to fill the holes, so the water escapes in a fun fountain.” 

(Easy! 3 Steps to the  Perfect Leak Proof Bag Science Experiment)

Materials:

Heavy whipping cream

Mason jar or any glass jar

Instructions:

1. Fill your Mason jar about half way with cream.

2. Take turns shaking the butter until it is agitated and the fat begins to clump. (It should take a few minutes for the fat to start to clump together, and the cream should look like whipped cream.)

3. After about 10 minutes of shaking, the cream should be converted into butter. 

4. The liquid separating out from the butter is the buttermilk. You can strain off the buttermilk, pouring it into a separate jar to save it for later to use to make pancakes or biscuits. The buttermilk is thin and slightly tart with little bits of butter left behind.

5. Pour a little cold water into the Mason jar with the butter in it. Close the lid, and shake the butter with the water to rinse off the remaining buttermilk.

6. Pour out the liquid. The buttermilk is being rinsed off so you have nothing left but pure butter.

7. If you want salted butter, you can add a bit of salt with the cream before shaking. 

Tip: If you want to spend less time shaking, take the heavy whipping cream out of the refrigerator, and pour it into the glass jar, and let it sit until it warms up and becomes room temperature. This will reduce the time you spend shaking the jar to make the butter.  

Science behind the lesson:

“When cream is shaken, the fat molecules in the cream leave their normal position and clump together. After a while, all of the fat molecules cling together, forming a lump of butter and leaving the buttermilk behind.” 

(Making Butter Science Experiment: The Science of Butter)

Materials:

A glass jar or a glass cup

A handful of popcorn kernels

A Tablespoon of baking soda

1/2 cup of vinegar

Instructions:

1. Fill your glass jar or cup about halfway with water.

2. Put the glass jar or cup in a bowl or pan so nothing gets spilled.

3. Pour your popcorn kernels in. 

4. Add the vinegar. Nothing will happen yet.

5. Add the baking soda.

6. Observe what happens.

Tip: You may need to stir the popcorn kernels up a bit to get them to start jumping.  

Science behind the lesson:

“This science experiment works through a chemical reaction. The two chemicals (baking soda and vinegar) react when mixed and form carbon dioxide (CO2) gas. The gas forms bubbles that collect around the popcorn kernels. The gas bubbles lift the kernels up to the surface of the liquid, and when the gas is released, the kernels fall back down into the jar, making it look like the kernels are dancing or jumping!” 

(Priddy)