Density with carbon dioxide
Initial Publication Date: August 25, 2009
Summary
In this activity, students will investigate the properties of carbon dioxide gas and air based on density. The teacher sets up the demonstration ahead of time by pouring carbon dioxide gas into a large see through container. (There are several different ways of getting CO2 in a container; which could be another lesson in itself.) Have students observe as you start to blow bubbles into the container. The students will be amazed to see the bubbles "floating in mid-air" in the container! (Or are they resting on something?) The questions and observations will begin!
CollapseLearning Goals
There are many goals for this activity. I use it to teach 3 areas in my Science class. First, I use it to teach about observation. Observing something helps students identify or put into words what they are seeing. If they can articulate what they see, they understand it. Next, this naturally leads to questioning. We can write down and edit many different types of questions that students come up with. This serves as a great way to model how to ask effective questions. Finally, I use it to teach students that air has matter. If they believe air (CO2) has density, then that air must have matter. It is a hard thing to get students to believe that the air around us has mass.
Vocab to review: mass, matter, density, carbon dioxide.
Vocab to review: mass, matter, density, carbon dioxide.
Context for Use
This is more of a guided demonstration meant for the entire class to observe. It can be done with any size class. It takes about two class periods to complete. One class period gets you through the demonstration and the next class period could be used to discuss the results and student responses.
I would recommend a document camera to project the action on a large screen if you have that technology.
I would recommend a document camera to project the action on a large screen if you have that technology.
Description and Teaching Materials
This activity could be kicked off with a discussion about air. Talk about what air is made of and that it actually has mass. Then, lead into to how to figure out density. Demonstrate that; Density = mass/volume. Remind students of the basic knowledge that more dense objects "sink" and less dense objects "float." Students will write down their observations, discuss the observations, write a hypothesis and then hold further discussion.
You will need:
bubbles (the stronger the better)
large, see-through container
carbon dioxide
scifun.org is where I first saw this experiment.
You will need:
bubbles (the stronger the better)
large, see-through container
carbon dioxide
scifun.org is where I first saw this experiment.
Teaching Notes and Tips
Try this activity on your own first. It can be a very powerful activity if done correctly.
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Assessment
Students will be graded on a test at the end of the unit. But, I also do check point quizzes and journal entries that help me identify who understands where we are currently at.
Standards
6.2.1.1.1 Understanding density