Lesson Plan: States, What’s the Matter?
Mark Chen – Boeing Fellows Program
Duke University
Grade Level: 3-5th Graders
Pre-requisite Knowledge:
- 2.P.1: Understanding the relationship between sound and vibrating objects
- Understanding of Models
State Standards:
- 3.P.2.2: Compare solids, liquids, and gases based on their basic properties
- 3.P.3.1: Recognize how energy can be transferred from one object to another
Introduction
There are three main states of matter that surrounds us: solid, liquid, and gas. Each one of these states has their own unique properties that distinguish it from the others. Students should be able to determine the properties of each state, and how these properties can interact with one another. Specifically, students should predict and observe how energy can be transferred.
In this lesson, students will first be exposed to the molecular configurations of different states of matter. They will draw out how “close” molecules are to one another, and how that distance affects the state of matter. They will also build their own device to record energy transfer.
Background
Matter makes everything around us, and it can be built by basic building blocks called atoms. Atoms are considered the basic unit of everything (although they can be further broken down into protons, electrons, neutrons, etc.[1]). They are also the building block of molecules, which are the fundamental units for non-element substances, like water and cheese! Since everything must be made of atoms and molecules, one thing that separates the different state of matter is how much movement the atoms or molecules have.
Solids generally have a fixed volume and shape because their molecules are locked into place. The molecules within a solid do not really move around. Think of a case of brand new water bottles; all the bottles are touching one another and cannot move at all. This is what happens in a solid. Molecules in a solid cannot move or slide past one another, but they can still vibrate in place.
Figure 1: (a) This is a visual representation of molecules in a solid state. (b) This water case is a model of molecules in the solid state. Note that both the water bottles and molecules are relatively packed together.
Liquids, on the other hand, have a fixed volume but take on the shape of whatever they are put in. The molecules in a liquid now can move around, and there is more space in between the liquid. Think back to the water case example. What happens when you remove a couple of water bottles from the case (but still left the remainder in the case)? The remaining bottles now can move around a little bit, although they are still constrained to whatever case they are in. The molecules in a liquid can move or slide past one another since there is a little free space between them.
Figure 2: (a) This is a visual representation of molecules in a liquid state. (b) This water case is a model of molecules in the liquid state. Note that both the water bottles and molecules have some space in between them.
Gases do not have a fixed volume or shape; the particles within a gas take up whatever space they can. This is because the gas molecules are so far apart that they just bump into one another once in a while. Now imagine your case of water, but with only one or two bottles left in the box. The bottles can roll around and be anywhere they can. Molecules within a gas can freely move past one another because there is lots of free space between them.
Figure 3: (a) This is a visual representation of molecules in a gas state. (b) This water case is a model of molecules in the gaseous state. Note that both the water bottles and molecules are relatively far apart from one another.
Now that you know how the different states of matter exist, let’s see how energy can be transferred between the molecules. Energy can be defined as the ability to do work, or move things around[2]. The amount of energy in the molecules composing in each of the three states of matter determines how much the molecules move around. The more energy a molecule has, the more it can move. Thinking back to our definitions of the different states of matter (solid, liquid, and gas), we can see why the gas molecules have more energy while solid molecules have less energy. Thus, the different states of matter just generally indicate how much energy that particular group of molecules has.
These molecules can also transfer energy. When molecules bump into each other, they can pass energy off to one another. This is kind of like a domino-effect: once one molecule gets a lot of energy, it becomes “excited” and can go bump into another molecule. The second molecule now has more energy, and it can go bump into something else. If more energy is introduced into a group of molecule, that group of molecules can move more and then pass on that energy to another group.
How can we conceptually understand what’s going on here? We understand processes and ideas through models. A model is really anything that simplifies or helps one learn; it can be thought of as a way of “telling a story[3].” For example, in the above explanation of solids, liquids, and gases, the water bottle case was our model of seeing how atoms interact with one another. Similarly, this exercise constructs a model for us to understand the transfer of energy: our model here will be sound. By listening and noting differences between the sounds, we are forming an intuitive model of how atoms can interact with one another and how energy from “tapping” goes from your finger to your ear.
Step-by-Step Activity
In this activity, we will see how energy can be transferred between different states of matter. Specifically, we will see (or rather, hear) how the energy made from tapping your finger can transfer through the states of matter. Students will also have an opportunity to build their own device to collect their own data. As an extension, students can also learn about how humans perceive sound (acoustic energy) through vibrations.
Set-Up (10 min per station, +an additional 5 min per station if cards are made)
The teacher should first prepare for this lesson by having three different stations: a “Solid” station, a “Liquid” station, and a “Gas” station. At the solid station, there should be a balloon filled with sand. At the “Liquid” station, there should be a balloon filled with water. At the “gas” station, there should be a balloon filled with air (roughly the same volume as before).
Note: the balloon should be a REGULAR balloon, and it should be placed within a bin to avoid possible leaks/bursts. Make sure that the balloon is latex-free if students have allergies.
Tip: To help get all the students engaged, a teacher may elect to keep the funnels and tubes at his or her own desk and have student “runners” come get them. If so, be sure to create cards or “badges” for each student. Examples include “Tube” or “Funnel.” Make sure there are enough cards for each item.
Background Information: Lecture before Activity
Students should be familiar with how different states of matter conceptually exist. Students should also know how models work (and how models are both useful and limited). (Tip: it might be useful for students to do a different activity to understand how models work before working on this activity).
Day of Activity
Students should be divided up into groups of three or four students. Each group should be given two funnels, a tube to connect the funnels, and tape to help assemble the device. The tubes should be pre-cut to about 6 inches long.
1. Students should first have a lecture on the different states of matter. Students should also understand that energy can be transferred between molecules by having the molecules bump into one another. (lecture)
2. Students should complete the first part of the activity hand out individually to see if they have enough background for understanding the material. (10 min)
3. Students can now break into different groups. This group should follow the instructions on part 2 of the hand out as to how to build the hearing device. (15 min)
Tip: To get all the students engaged, consider having the necessary materials at your desk and giving the students certain “material cards.” For example, one card might say “tube” and another might say “funnel.” Only students carrying those cards can “trade-in” for the actual part at the desk.
Tip: To save time, these devices can also be pre-constructed. That way, the students can focus on just getting data and analyzing it.
4. Students should now go around to different stations to collect data (as indicated on part 3). Each student should place one end of the device at the station and the other end on their ear. They should then tap the station (i.e. the balloon) and record what they hear. (15 min)
5. Students can then return to their desk and finish the worksheet. (10 min)
6. OPTIONAL: If there is time left over in the class period, you may discuss with the students what this device may be used for. Some examples include a stethoscope (listen to the sounds of your heart)
Reflection/Assessment
Students should have filled out the worksheet (to be graded). They should have explained what differentiates between different states of matter, and they should have learned how energy can be transferred. They also have their recorded data from their activity, and they should be able to explain their results. Students can also extend their knowledge by considering other applications for their device.
Extension
After conducting the exercise, students should have gotten the following results. The “solid” station should have a soft and short sound. The “liquid” station should have a rather low-pitched sound (and it may last longer). The “gas” station should have a short sound.
The idea that this lab demonstrates is that a “solid” should transfer energy better than the liquid and gas. However, the students’ results should show that the water balloon transferred sound better. To explain this, introduce to the students the idea that there are different types of energy, such as thermal, acoustic (sound), electrical, etc., and the medium of which sound propagates affects it. For a more in-depth lesson on how different environments affect sound, see the lesson plan created by the Kenan Fellows Program at UNC[4].
[1] http://www.livescience.com/37206-atom-definition.html
[2] http://www.livescience.com/42881-what-is-energy.html
[3] http://www.learner.org/courses/essential/physicalsci/session2/closer1.html
[4] http://www.learnnc.org/lp/editions/biomusic/6517