Eliciting Student Ideas: What is Air? What is a Gas?

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Students will be able to identify their initial thoughts on the composition, properties and methods of measuring air and gasses as the first in a series of lesson on understanding Earth's atmosphere.

Big Idea

A useful starting point for a middle school unit on weather. This lesson will give you insight into your students prior held understanding of air versus gasses.

Getting Started

The goal of this activity is for students to identify their prior knowledge on the composition, properties and methods of measuring weather and air. There are many common misconceptions about air. It is important to be aware of these before beginning, so that you can probe for them - and explicitly address them - to ensure student understanding. 

Materials Needed:

  • Student Science journals and pencils
  • Poster paper or white boards
  • colored markers

Note on student grouping: For the first part of the activity, students will work by themselves for about 10 minutes then work in groups of 3-4 for the remainder of the activity.


5 minutes

Elicit students ideas by asking them respond to the following questions in their journals without talking to their neighbors. (5-7 min) If they have clarifying questions for you, try not to give any content specific information at this time. You want only their initial ideas, not the “right answer.”

  • What is air and what are the properties of air?
  • What is a gas and what are the properties of gases?

 The value of this step is for you to have an opportunity to collect some "data" on what your students know prior to the lesson. I have found this to be a critical part of the flow of my teaching as it helps me recognize potential misconceptions and challenges to the lessons ahead. 

Give students 5-7 minutes to write their ideas down. Have them get into groups of 3-4 students and give each table a large sheet of poster paper or if you have white boards, one large white board per group along with colored markers.

NOTE: You might consider separating these questions across two different classes. 


15 minutes

Working in groups, ask students to create two posters with GAS in the center of one and AIR in the center of the other.  Using their collective ideas and questions they should create mind maps to group and connect their responses.

NOTE: Encourage them to FIND CONSENSUS within their group, but HONOR ALL IDEAS. They may have FRIENDLY DEBATES, but this is not the time to have the “right answer.”

If you or your students have not had any experience creating Mind Maps, please read How to Make A Mind Map® before you begin this lesson. This is a powerful brainstorming tool that I use frequently with both my students and my colleagues and there are some simple to follow protocols that will make the process run better if followed. 


15 minutes

Explain: Ask each group to share their posters with the class.

I do not correct any misconceptions at this time, nor do I let any debate, questions or discussions. If students have questions, we record them on a poster and address them later. 

Also, I like to sit to the side or at the back of the class and take general notes about the students' ideas. I find these notes helpful when planning future lessons. 

I like to emphasize some basics of public speaking to the class before we begin. While these are by no means formal presentations, I still ask students to make sure to speak clearly, face their audience, not their posters, keep hands to their sides or hold in front, stand up (they like to lean on the white board), etc. 

Be mindful of time as this part can run overtime if not managed well. You may want to use a timer to keep things on track. Some students (and teachers as well) can be long winded. One strategy I like to use is to ask kids to explain their answer in 20 words or less. This challenges them to think carefully, be concise and hopefully clear.


20 minutes

You may wish to assign homework to continue student thinking around the topic of characteristics and properties of gasses. I like to use science probes from the NSTA Press published series by Page Keeley titled Uncovering Student Ideas in Science. 

Suggested Homework  - Assign Science Probes*: Hot and Cold Balloons & Floating Balloons. These two probes focus on the relationship of temperature, pressure and density of gases. 

*Uncovering Student Ideas in Science (Volume 3)- Another 25 Formative Assessment Probes by Page Keeley, Francis Eberle, and Chad Dorsey (2008) 

 If you have not used any of the science probes from the series, please read below.

From the website: Uncovering Student Ideas in Science, Volumes 1-4, provide a set of grades K-12+ formative assessment probes that link key concepts in science to commonly held ideas described in the research on learning. These probes can be used to reveal the variety of conceptions, including misconceptions, naive ideas, partially correct or incomplete ideas, and scientific ideas students bring to their learning. Used individually or as a set, these probes provide the diagnostic and formative tools science teachers at all grades need to uncover the preconceptions students bring to their learning and inform pathways needed to build a conceptual bridge from where students are at any point in the instructional cycle to where they need to be scientifically.

If time permits to complete in class, ask students to discuss their ideas with their lab group. Ask them to come to consensus and have a spokesperson share out to the class. Teacher should record ideas on poster paper. Save these ideas and return to them throughout the lessons and labs that follow and have students evaluate these initial ideas and change as they see fit.