Pop Rocks Science
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Warning!
Adult supervision: (choking hazards, liquids not for drinking, etc.)
 Please read the procedure before beginning! After reading, please watch the video. Some activities require more time and cleanup than others. You also have the choice of performing these activities in a way that suits your needs.
 Materials
- Pop Rocks
- Jar of Water
- Jar of Dish Detergent
- Jar of Liquid Glue
- Jar of Liquid Starch
- Experiments use the scientific method. First, ask a question: Does the viscosity of a liquid affect how Pop Rocks pop?
- Next, make observations. Observe to determine the viscosity of each of the four liquids. Place the jars in a row on a tray or in the STEM SAK box in order from least viscous to most viscous to prepare the experiment.
- Now, form a hypothesis (or statement) about how the viscosity or other properties of the liquids may affect how the Pop Rocks pop.
- Now, test the hypothesis. Drop a small amount of Pop Rocks in each liquid.
- Next, take data. Listen to the Pop Rocks in each liquid, and make note of which ones pop the most/loudest and which ones pop the least/quietest.
- Finally, determine the conclusion. Was the hypothesis correct? If not, what is the conclusion? Ask more questions and go through the process again. Is it the viscosity of the liquids that affects the pop rocks, or could it be something else?
- Which variable in the experiment was the independent variable? Which one was the dependent variable?
- Optional: Set up a viscosity race with the leftover liquids! Prop up the STEM SAK box or a tray at an angle. Hold a jar of each liquid in each hand, and have a friend hold the other two. Count down, and pour the liquids down the slope to see which reaches the bottom first.
Science Behind it!
    Pop rocks are tiny pieces of hard candy that are mixed with a highly pressurized gas known as carbon dioxide. This gas is similar to the gas that expels out of your mouth when you have had too much to eat or drink, what plants need to live, and what escapes when you open a can of soda. This carbon dioxide is blown into the hard candy and then broken into a billion pieces, which you know as pop rocks. When you place the pop rocks into your mouth, the tiny air pockets where the carbon dioxide is, wants out, so it expands in your mouth! Cool!
    This experiment teaches you how to use the scientific method. The scientific method is a tool we use all over the world to logically solve scientific problems through critical thinking. The steps to this process are: come up with a question, observe (think of your senses), formulate a hypothesis, test your hypothesis, collect data, and determine a conclusion.
    Viscosity means how think something is. There can be high viscosity, that is thick like honey or lava. What might have a low viscosity, that is thin?
    The independent variable is the variable in the experiment that is changed on purpose by the person doing the experiment. The dependent variable is what is being tested. A great example is determining if how long you sleep affects your test scores at school. The independent variable is the number of hours you sleep which affects your test score, the dependent variable.
    What are some other ways or methods in which to test pop rocks?
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