And kids from John Hay Community Academy Boys & Girls Club and Carter Boys & Girls Club
John Hay Community Academy
Boys & Girls Club
Rock Candy Science Project
- Rock candy is formed by allowing a supersaturated solution of sugar and water to crystallize onto a surface suitable for crystal nucleation, such as a string, stick, or plain granulated sugar.
- Heating the water before adding the sugar allows more sugar to dissolve thus producing larger crystals.
- Crystals form after six or seven days.
- The Hay Club conducted multiple experiments, including whether a string or a wooden stick would grow faster over a seven day period (wooden stick).
GROW YOUR OWN ROCK CANDY (90-120 MINUTES)
Introduction: This activity will introduce participants to a concept known as a physical change. A substance may sometimes change color, shape or appearance, but otherwise remain the same.
This is known as a physical change. Sometimes an object loses energy or changes its state of matter, (e.g. liquid to a gas). This is known as a chemical change.
Objective: To introduce participants to the concepts of physical and chemical changes.
NGSS Alignment: 5-PS1-1: Develop a model to describe that matter is made of particles too small to be seen.
5-PS1-2: Measure and graph quantities to provide evidence that regardless of the type of change that occurs when heating, cooling or mixing substances, the total weight of the matter is conserved.
Facilitator: Participants will use a hot, boiling solution for part of this activity! Make sure participants are safe while handling hot containers and transferring the boiling solution, which can cause a bad burn if spilled.
Instruct Members To:
- Take two minutes to pick one person to gather all the materials for this project.
- Cut two pieces of yarn 1-2 inches longer than the height of the Mason jar.
- Set one string to the side until later in the activity – this is your control string.
- Seeding the rock candy:
- Soak the second string of yarn in water for 7-10 minutes. This is the yarn that will seed your rock candy.
- Squeeze the water from the string so that it still remains moist, but it not dripping wet.
- Roll the moistened string of yarn in 1 tablespoon of sugar on a plate.
- Play with varying quantities of sugar and use this later as a class comparison.
- Place your seeded (sugar-coated) string and your non-seeded string on a piece of wax paper, make sure they are not touching. We will continue with part two of this activity tomorrow.
- Review materials to be used as weights and find substitutes when needed.
- Divide members into their teams and ask them to retrieve the strings that were prepared in the previous session.
Instruct Members To:
- Take each of your strings and tie one end to a small object that serves as a weight. Some sugar may fall off of the string during this step (this is okay!).
- Tie the other end of each piece of string to a pencil or other object that serves as an anchor.
- Use a marker, colored tape or another method to mark the pencil that holds the seeded string.
- Write down what you marked on your seeded string in your lab notebook in case you forget later.
- Lower the weighted end of the string into each of the jars, rest the pencil across the top (mouth) of the jar.
- Each string should be about 1 centimeter from the bottom the jar. You may have to roll your string around the pencil to adjust the height.
These next steps are very important. Please take your time and be careful as you’ll be working with hot water!
Instruct Members To:
- Fill each jar with boiling water using a funnel or other device to reduce the risk of splashing water and spills.
- Keep the boiled water in each Mason jar until you are ready to replace this water with your sugar-water solution.
GROW YOUR OWN ROCK CANDY C MAKING THE SUGAR-WATER SOLUTION (30 MINUTES)
Facilitators: Complete the following steps for the group and give out appropriate amounts of the solution for each group to complete the activity.
- Use a measuring cup to add 1 cup of water to a pot, bring the water to a rolling boil on the stove.
- Reduce heat to low.
- Use a measuring cup to add 2 cups of sugar to the hot water, then mix with a wooden mixing spoon until all the sugar has dissolved.
- Turn the heat back up and wait until the sugar-water solution returns to a rolling boil, keep stirring to keep the solution consistent.
- Remove the boiling sugar-water solution from the stove.
- Continue to add 1 tablespoon of sugar at a time to the solution. Stir thoroughly after each spoonful, making sure the sugar is completely dissolved before adding more.
- Continue adding sugar until no more dissolves in the solution. After all the sugar has dissolved, let the solution cool for five minutes.
Making the Candy:
- Pour the hot water out of the preheated glass jars.
- After the sugar-water solution has cooled for five minutes, pour the solution into the two preheated glass jars, dividing the liquid equally between the two containers.
Flavoring the Candy:
- Flavor the sugar-water solution with individual packets of flavored candy or squeeze bottles used to flavor water.
- Sample different flavors of rock candy at the end of the activity!
Safety: Be extremely careful when handling the jars of sugar-water solution. It is hot and will burn if spilled on your skin. This step may be completed for participants by the facilitator.
- Using potholders, move the jars of sugar-water solution to a place where they can be left undisturbed for one week. Place both jars in the same location.
- Temperature may disrupt the crystallization process. Avoid putting the jars in direct sunlight, or where they may be exposed to extreme hot or cold temperatures.
- Lower the weighted strings into the jars of sugar-water solution, one string per jar.
- Tape the pencils to the edges of the jars to prevent them from falling/rolling off.
- Cover the jars with a paper towel to prevent dust and debris from flying in.
Carter Boys & Girls Club
Enviro Battery Science Project
- The enviro battery works by immersing a pair of connected zinc and copper plates into a potato, mud, water, or a piece of fruit. The Carter Club used a lemon, potato, and water.
- The zinc plate is the negative electrode, and the copper plate is the positive electrode. When the metals are immersed in the electrolyte, a chemical reaction takes place.
- Zinc is a more reactive metal than copper in this chemical process. It generates electrons faster than copper in this chemical process. The excess electrons flow from the zinc plate to the copper plate.
- This flow of the electrons from a reactive metal to a less reactive metal forms a small current which was strong enough to power a small clock.
Your enviro battery works by immersing a pair (or pairs) of connected zinc and copper plates into an aqueous medium such as a potato, mud, water, or a piece of fruit. The zinc plate is the negative electrode; the copper plate is the positive electrode. When the metals are immersed into the electrolyte, a chemical reaction takes place. The acid in the electrolyte breaks down the atomic structure of the copper and zinc, causing individual electrons to be released. Zinc is a more reactive metal than copper in this chemical process. It generates electrons faster than copper in this chemical process.
The excess electrons flow from the zinc plate to the copper plate. This flow of the electrons from a reactive metal to a less reactive metal forms a small current which is strong enough to power a small light bulb, a small watch or a sound chip.
From the kit: The LCD watch movement with its protective cover, 2
zinc plates, 2 copper plates, adhesive tape and a connecting wire.
From home: 2 potatoes or any fruits e.g. lemons, apples.
THINGS YOU NEED TO KNOW
There are universal standards for positive and negative terminals. The positive terminal is always the red coloured wire, whereas the negative terminal is always black. Always connect the negative terminal to a zinc plate (or a more reactive metal) and the positive terminal to the copper plate (or a less reactive metal). Note: It is important that the exposed wire and the plate touch. Use the transparent tape provided in the kit to further secure the connection.
- Connect the black wire from the LCD watch (negative) to one of the zinc plates by carefully threading the wire’s exposed metallic end through the hole on the plate. Gently twist the wire to secure it to the plate.
- Connect the red wire from the watch (positive) to a piece of copper plate.
- Assemble a “connection pair” by connecting the other pair of copper and zinc plates with a connection wire.
- Now that all of the components are connected, insert the copper and zinc plates into the potatoes as shown in the diagram. Voila! You have created a battery to power the LCD clock! (See section M for setting the clock)