Week of June 8, 2020
The goal of the NEWESD 101 Science Kit Cooperative is to send out weekly science challenges to our members. The challenges will sometimes be tailored to a grade level, or a more general challenge which can be adjusted or added to based on the grade level you are teaching.
If you are needing any science materials to show demos to your students during your virtual meetings, please let me know and we will do our best to accommodate any requests.
Grades K-2: Make Your Own Super Bouncy Ball
- 1/2c warm water
- 1T Borax
- 1-2 T clear Elmer's glue (or Elmer's clear glitter glue) generic glue found at places like dollar store don't seem to work.
(Let your parents help here). You want to stir together the 1/2 cup of warm water and 1 tablespoon of borax, until it is completely dissolved (add more water if it doesn’t all dissolve). If the water is hot, allow it to cool. To get the light blue translucent glitter super bouncy ball in the photo, we combined clear and glitter glue together as we poured it into the borax solution.
Next slowly pour your desired amount of glue into the bowl of borax solution. The more glue you use, the bigger the ball! (We used about 2 tablespoons of glue)
As soon as the glue hits the borax solution it will start to harden. Gently squeeze and squish the glue ball until it is no longer sticky. Remove from the borax solution and roll between your hands to make it ball shaped.
Grades 3-5: Invisible Ink
What better way to get kids excited about science than with an experiment straight out of a spy novel? Write a secret message using colorless ink, wait for it to dry, then use a special secret solution to reveal the message.
- 1/2c water
- 1T baking soda
- Q-tips (or a paintbrush) to apply invisible ink
- 1/2c rubbing alcohol
- 1tsp turmeric
- Paper towels (or a paintbrush) to apply color-changing solution
- Measuring glass
- Measuring spoon
- Spoon for stirring
- Add 1T baking soda to 1/2c water.
- Stir the baking soda into the water to make the “invisible ink”.
- Use q-tips (or paintbrushes) to draw a picture with the invisible ink on paper.
- While you are waiting for your paper to dry, mix up your color changing-solution. First, add 1 teaspoon of turmeric to 1/2 cup of rubbing alcohol.
- Stir the turmeric into the rubbing alcohol. (Note: The solution can stain a little bit. I used a white plastic bowl, which was not the smartest, because it was a little difficult to clean afterwards. You might want to use a glass bowl.)
- After the paper is dry, use a paper towel (or paintbrush) to apply the color changing solution to the paper to reveal the secret message! (Note: We used paper towels, but our hands were all a little orange for a few hours afterwards, so you might want to use a paintbrush instead!)
Grades 6-8: Bioplastics
- Access to stove
- Access to cooking pot
- Gelatin packets (3) (not jello)
- Food coloring
- Silcone molds (optional)
- Add 1/3 cup of water and 3 gelatin packets to the pot. If desired add 2 or 3 drops of food colouring. Whisk together over medium low heat until completely mixed.
- Once the mixture starts to steam and thicken a bit, remove it from the heat.
- Using your spoon gently scrape the foamy layer off and discard. If you don’t remove all the foam now it will cause some cloudiness in your final plastic. This isn’t all bad and we left it on some batches and removed it on others. The better you are at removing the foam, the more clear your final plastic will be.
There are different options for what you can next for forming your gelatin plastic.
- You can pour your solution onto a container lid and leave it for about 45 minutes. After 45 minutes you will have a rubbery consistency material. You can cut it with cookie cutters, scissors, or a knife. You can shape it by hand. It’s neat to play with and I recommend doing this with at least one batch. We left ours on the lid because we wanted to see what would happen. Turns out as it cures into a hard plastic it twists and lifts creating neat shapes. It took about 2 days to cure completely and give us hard plastic.
- The second option is to use silicone molds. Carefully spoon your liquid solution from the pot into your silicone molds. I found it was better to fill the molds and make them quite thick. If we only added a bit to make thinner pieces, they tended to twist and curl in the molds as they set. The issue with making them thick is that it takes much longer to harden and set. Our thickest pieces spent 4 to 5 days in the molds curing, then another 2 days hardening before they were completely cured. But you can get the coolest little plastic shapes!
How it works
This project, along with our milk plastic experiment, create what is known as bioplastics and are created from biomass or organic matter. Bioplastics are different from most mass produced plastics that are created from fossil fuels.
Gelatin is created by breaking down collagen which is found in all animals where its function is to bind cells together. Collagen is a very long chain of amino acids, the building blocks of proteins, that bonds to itself in a triple helix pattern.
Gelatin is long chains of hundreds of amino acids. At room temperature it is solid, but when you heat it up the bonds between the chains loosen, allowing them to slide and stretch apart. Gelatin also has a strong affinity for water. Hydrogen atoms that are attached to the side of the chains can bond with water molecules. When we heat up and mix our solution we are weakening the chains, then during the cooling process those hydrogen atoms form connections with the water molecules. This is called a hydrogen bond.
In our solution we have added a LOT of gelatin to a fairly small amount of water. All those water molecules bond with the hydrogen molecules, then the amino acid chain also starts to bond with itself, trapping those water molecules within it’s complex 3D structure. If we used more water, we would end up with more of a gummy candy consistency or even a jello consistency. But in this experiment all the water molecules are used up, so once it finishes curing we end up with a very hard plastic.