Week 3: April 20-24

Learning Goal: Students will learn about solubility to identify ways to show that matter can be made of particles too small to be seen. They will investigate saturation points of various salts and sugars.

• I can determine the solubility of a solid material (solute) by attempting to dissolve it in water (solvent).
• I can determine the saturation point of a solute by adding it to the solvent until it no longer dissolves.

Estimated Time for The Week:

30 minutes

Type of Lesson:

Solubility and Saturation Level

Materials:

• Leaves, dirt, grass
• Flour, corn starch, powdered drink mixes
• Various salts that you have at home - table salt, Kosher salt, Epsom salts, garlic salt
• Various sugars that you have at home - granulated sugar, powdered sugar, brown sugar, sugar substitute such as Splenda or Equal
• Clear cups or containers
• Water
• Measuring cup
• Teaspoon
• Muffin tins
• Saran Wrap (plastic wrap)

Background Information:

• Some solid materials dissolve in water. Add a variety of found household materials to water and investigate which will dissolve.
• Solutions form when the material (solute) is soluble in water (solvent). The solid particles dissolve until they can no longer be seen with your eyes. Younger children would say that it’s magic and it disappeared, but older students realize that the materials are not gone; they are still there, but they can no longer be seen.

Definitions Rewind and Remind:

• Solubility: the property a substance has of dissolving solvents, such as the solubility of salt in water
• Soluble: capable of being dissolved
• Solution: a mixture formed when one or more substances dissolve in another
• Solute: a substance that dissolves in a solvent to form a solution
• Solvent: a substance in which a solute dissolves to form a solution
• Saturated: when the solvent cannot dissolve any more solute
• Saturated solution: a solution where the solvent cannot dissolve any more solute
• Supersaturated solution: when a solution contains more solute than it normally would at a given temperature or pressure
• Dissolve: the process of a substance becoming incorporated uniformly into another
• Concentration: the ratio of solute to solvent in a solution
• Concentrated: a solution containing a lot of solute

Learn & Practice:

1. Warm Up: Watch this video What is a Saturated Solution?
2. Investigation - Part One:
   • Label the muffin tin with the various types of salt and sugar that you found in your home and set aside for later use. (*Read part two of the investigation for detailed instructions prior to beginning this experiment.)
   • Place four ounces of water in a clear cup or container.
   • Using the salts and sugars that you found around the house, add one level teaspoon and stir.
   • Continue to add teaspoons until the water will not hold any more. You will know that it has reached the saturation point when no matter how much you stir, powder collects at the bottom of the container.
   • The solution has become very concentrated, but the water can only hold so much!
   • Pour a small amount of the solution into your labeled muffin tin for later use.
   • Write down how many teaspoons it took to reach saturation.
   • Repeat steps 2 - 6 for each type of salt and sugar that you have available.
   • Build a table and chart the different materials.
3. Questions to Ponder:
   • Which solute took the most number of teaspoons before reaching saturation?
   • Do all sugars dissolve in water equally?
   • Can water hold as much salt as sugar?
   • Can you see a correlation when you bake? Consider the amount of sugar in a recipe as compared to the amount of salt.
   • Can you recover your sugar/salt crystals so that they are visible once again?
4. Investigation - Part Two:
   • Label your muffin tin or small containers with the types of salts and sugars that you dissolved in the water.
   • You may want to line the muffin tin with aluminum foil or plastic wrap to make sure the salt does not corrode your dish.
   • Pour a little of your solution into the labeled container.
   • Set aside and observe daily as the water evaporates.
   • Once the water is gone, you should have salt and sugar crystals.
5. Questions to Ponder:
   • Where did the water go?
   • Do all of the crystals look the same? If you have a magnifier of some sort, you will be able to examine the crystals with greater detail. You can even take a picture with your phone and zoom in closer.
   • Do the crystals look like the materials did before being dissolved?
   • How did they change? Compare the original substance with the one you have now.
6. Optional Extension Activities:
   • Make your own rock candy!
     1. Materials: wood skewer or chopstick, clothespin, 1 cup of water, 2-3 cups of sugar, a tall narrow glass jar/cup
     2. Clip the skewer to the clothespin so that it hangs down on the inside of the glass jar and is about 1 inch from the bottom of the jar. Remove and set aside for now
     3. Have your parent(s) help!
     4. Pour water into a pan and bring to a boil
     5. Pour ¼ cup sugar into boiling water, stirring until it dissolves
     6. Keep adding more and more sugar, stirring until it dissolves, until no more dissolves. (This takes time! Be patient and make sure you stir and give it time to dissolve)
     7. Once no more sugar will dissolve, remove from heat and let cool for about 20 minutes. You just made a SUPERSATURATED SOLUTION
     8. Have your parent pour the supersaturated solution in the glass jar almost to the top. (Add a few drops of your favorite food coloring color!)
     9. Place the skewer/chopstick with clothespin in the glass jar so that it hangs straight down
     10. Place your jar somewhere that it won’t be disturbed
     11. Sugar crystals will form for 3-7 days. Enjoy your tasty treat!
   • If you finish this assignment, and want to continue to do more science, then continue with this. In the beginning of the school year, we discussed the different phases of the moon. This would be an additional skill that would be worth reviewing. Below is a link that allows you to journal and track the phases each night. It is not required, but might be fun for the students who really enjoyed the Earth and Sun Foss unit: Moon Phase Journaling

Learning Goal: The student will expand their understanding of the Four C’s of Engineering: collaboration, creativity, critical thinking, communication.

I can create a catapult and set goals to see how far my catapult can launch a piece of candy.

Estimated Time for The Week:

30 minutes

Materials:

• Candy (or other soft, non-breakable items)
• Tape
• Scissors
• Paper
• Markers
• A ruler, tape measure or yardstick
• Objects found around the house

Click the link for printable instructions for this lesson & many more: Candy Catapult

Learn & Practice:

For the Google Slides to click-through the below directions, click here! (It includes pictures for the steps below.)

1. This week’s challenge will be to catapult a piece of candy 10 feet.
2. This week is the 50th Anniversary of Earth Day on April 22nd! Look around the house for items you can use to construct your catapult (check the recycle bin, junk drawer, and garage). Try to use things like clothespins, spoons and scrap wood or any items that can be recycled to build a catapult!
3. Simple machines are everywhere. Think of some examples to help you create a catapult (spoons, pencils, tongs, rubber bands, scissors).
4. Design and draw a catapult design.
5. When design is complete, construct your catapult based upon your drawing.
6. Now, you need a target. Design a target to hit.
7. Go back to your original drawing and redesign your catapult to increase the accuracy and distance.
   • How far do you think your candy will travel now?
   • Can you change how far you pull back on your catapult to reach different targets?
   • Will making your catapult shorter or taller make a difference?
8. Next, try launching marshmallows, other candy or soft toys to test how materials of different weights travel different distances!
9. Can you reach twenty feet? Thirty? More? Add additional targets at these distances. Your target area might look a lot like a skeeball game, Topgolf course or football field etc. Take a look at some ideas for your target area in Slide #10 from the Google Slides.

Explanation:

Why does a catapult fling candy so far?

Catapults use a simple machine: the lever. The purpose of a lever is to make a load (in this case, candy) easier to move. There are four parts to a lever: a rigid bar (arm), pivot point (fulcrum), the object being moved (load force) and the force applied to move the load (effort force). Catapults use stored potential energy to eject the candy across the room. This stored potential energy transfers to kinetic energy as the candy is launched. Combining kinetic energy with a simple machine makes a task like hurling a piece of candy very exciting!

Extras:

Read this article, Catapult Facts, or watch this video, Fixies Catapult, to learn more about catapults.

If you want to, document your experience as you go and upload your work through photos or video to Class Dojo, Seesaw, Google Classroom, or whatever format you are using for your teachers to see! Most importantly, HAVE FUN!!!