Think back to a time when you could smell something cooking in an oven before you entered the room.
How is it possible for you to smell something cooking before you can see it?
Overview
In this activity, students discuss odors and why things can be smelled from a distance. The teacher releases an odor from two sources in the room. Students record when they detect the odor as well as the strength of the odor over time. After observing a “play back” visualization of the detections patterns recorded by all the people in the room, students analyze the data using a computational model. Students share prior knowledge and ideas about particles and molecules that they believe are relevant and might help account for the observed phenomenon. The teacher then demos the next model the students will use. The students take interactive notes about the capabilities of the gas particle “sandbox” model and choose a research topic/question (of their design) to investigate related to gas particle interactions.
Standards
Computational Thinking in STEM
- Computational Problem Solving Practices
- Developing Modular Computational Solutions
Acknowledgement
Cite the Modelsim research
Activities
- 1. Exploration 1 - Predict
- 2. Exploration 1
- 3. Discoveries and Insights
- 4. Exploration 2 - Brainstorm
- 5. Exploration 2 - Model Rules
Student Directions and Resources
In this activity, you will discuss odors and why things can be smelled from a distance. You will need to call upon and share your prior knowledge and ideas about particles and molecules that might help account for the observed phenomenon. You will also use a computational model to explore this phenomenon.
Today we begin our unit on the particulate nature of matter, or PNoM for short. Throughout this unit you'll have the opportunity to ask questions about why matter behaves the way it does and you'll be given the tools and freedom to find answers to those questions!
The first activity in this unit is on detecting odors.
1. Exploration 1 - Predict
Question 1.1
2. Exploration 1
“What patterns are there in how odors travel?“
Predict
Your teacher will open two containers at different locations in the room at about the same time, both containing the same substance, but at different temperatures. The substance is one that will have a recognizable odor.
Question 2.1
What patterns do you think you will see in which people will detect the odor first?
Question 2.2
Which people in the room do you think will be the last to detect the odor?
3. Discoveries and Insights
Now that you've considered how odors behave in a room, you will get to experience it directly. Your teacher will bring out some odors and allow them to diffuse throughout the room. While this happens, record your observations and thoughts and then answer the questions below.
Question 3.1
What do you observe while the odor is diffusing throughout the room? Consider taking note to the intensity of the smells you experience and any changes you notice over time. Take note of who smells the odors first in the classroom and what happens to the odors over time.
4. Exploration 2 - Brainstorm
After experiencing odor diffusion in a room, you may have a better idea of what affects this process. Answer the questions below to explore this.
Then consider how we can model particle movements during diffusion?
Question 4.1
How do you picture the odor moves from each container throughout the room? Draw a sketch below
Note: Draw your sketch in the sketchpad below
Question 4.2
Why do you think odor levels may fluctuate up and down for some people in the room over the length the entire experiment?
Question 4.3
What do you know about gases and molecules that may help further explain your answers?
Question 4.4
What variables or factors might affect how an odor spreads across a room?
5. Exploration 2 - Model Rules
In the next activity you will be working in a team of two people to build a model of the phenomena you observed. Using a "sandbox" model -- which is a model that provides the tools, agents, and behaviors of a system, but allows you to design the system -- you will attempt to replicate the behavior of odors as they move around a room.
The model is introduced below. Here is how you can run the model:
1. Press the SETUP button on the top left to reset the model.
2. Press the GO/STOP/ADD ELEMENTS button the run the model. This button will turn dark blue meaning the model is actively running.
3. You can pause the model by clicking the GO/STOP/ADD ELEMENTS button again.
Explore the model freely and answer the questions below.
Question 5.1
How can particles of different substances be distinguished from one another?
Question 5.2
How can solid obstacles be added to the model?
Question 5.3
How can removable obstacles (such as doors or lids) be removed or replaced in the model?
Question 5.4
How can molecules be sped up or slowed down?
Question 5.5
What visualization cues can change in the model to help you better see the relative speed of the molecules?
Question 5.6
Once you have made a model, how will exporting the world help you conduct future experiments?
Question 5.7
You will need to carefully consider the mechanism you are trying to model. In the space below, explain what mechanism you believe is responsible for the patterns observed in odor diffusion and describe how you intend to test whether or not your hypothesis is correct.
