Produced with Scholar
Icon for The Behavior of Particles and Gas Laws

The Behavior of Particles and Gas Laws

Learning Module

Abstract

This is a learning module designed for a high school chemistry class. It covers kinetic molecular theory and gas laws and their application. It focuses on modeling and includes a final project.

The study of gases and gas laws is important for all students to understand. Through the study of Gas Laws, students gain an understanding of the particulate nature of matter and are able to create models of how the individual particles that make up matter behave in different states and how they respond to changes in pressure, temperature, and volume. Students are also able to use mathematical models to make predictions on how variables will change with changing conditions.

This learning module is designed for a high school chemistry course and covers a basic overview of kinetic molecular theory and a conceptual and mathematical understanding of the gas laws. The end project in this module has students design and carry out an experiment to use what they learned about gas laws to test variables and analyze results. 

I have been teaching High School Chemistry for over 10 years and have taught all levels. Although I have taught this unit before, I have always approached it in a traditional manner, by giving notes to the whole class and having students complete various practice problems throughout the unit. The lab that I have traditionally used to enhance the content consisted of mini- demonstrations where students would need to identify the gas law being demonstrated.  For this learning module, although I kept the content the same, I changed the way students learned. Instead of me telling them the information in class, I have them read and watch videos to learn the content on their own. Students then are challenged to find examples of the concepts in their own life in order to apply the content to familiar experiences they have witnessed outside of the classroom.  This will allow students to actively contribute to the knowledge of the class by bringing in their own observations and experiences. 

Before starting this unit, students should have a basic understanding of the structure of the atom and the mole. 

This learning module should take approximately 2-3 weeks depending on the length of time given in class for the final project. 

Learning Standards Addressed

NGSS Standards

HS-PS1-7: Use mathematical representations of phenomena to support claims.

HS-PS1-2: Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

Common Core Mathematics Standards 

MP.2: Reason abstractly and quantitatively.

MP.4 Model with mathematics.

HSN-Q.A.1 Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.

HSN-Q.A.3 Choose a level of accuracy appropriate to limitations on measurement when reporting quantities.

District-Wide Essential Science Skills: 

ES1: Use mathematics and computation as fundamental tools for representing physical variables and their relationships and for a range of tasks such as constructing simulations; statistically analyzing data; and recognizing, expressing, and applying quantitative relationships.

ES2: Use and construct models as helpful tools for representing ideas and explanations. These tools include diagrams, drawings, physical replicas, mathematical representations, analogies, and computer simulations.

ES3: Use observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

ES4: Investigate and explain causal relationships and the mechanisms by which they are mediated. Can use relationships of cause and effect to predict and explain events in new contexts.

ES6: Use skills of collaboration, creativity, critical thinking, and communication to design, execute, and communicate scientific investigations.

Unit Instructional Objectives: 

Students can describe the arrangement of particles in solids, liquids, and gases.

Students can predict how a gas will behave in response to a change in temperature, volume, or pressure.

Students can calculate the change in pressure, temperature, or volume of a gas when 1 or more variable is changed.

Students can calculate pressure, volume, temperature, or moles using the Ideal Gas Law Equation

Students can ask questions that can be investigated within the scope of the school laboratory, research facilities, or field (e.g., outdoor environment) with available resources and, when appropriate, frame a hypothesis based on a model or theory.

Students can use valid reasoning, good judgment, and systems thinking to form ideas or solve problems.

Students can conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating an understanding of the subject under investigation.

Students can produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.

 

Update 1

For the Student

By the end of this update, you should be able to describe the arrangement of particles in solids, liquids, and gases. 

Watch the brief video below for an introduction to the Kinetic Molecular Theory: 

Media embedded September 28, 2019

Video From: Scámarca Productions, 2016

The video describes how energy in the particles varies depending on the state of matter. The following reading passage from Boundless describes in more detail the ideas of Kinetic Molecular Theory. 

                    The Kinetic Theory: A Microscopic Description of Matter

The kinetic molecular theory of matter offers a description of the microscopic properties of atoms(or molecules) and their interactions, leading to observable macroscopic properties (such as pressure, volume, temperature). An application of the theory is that it helps to explain why matter exists in different phases (solid, liquid, and gas) and how matter can change from one phase to the next.

Image from Boundless Chemistry

The kinetic molecular theory of matter states that:

  • Matter is made up of particles that are constantly moving.
  • All particles have energy, but the energy varies depending on the temperature the sample of matter is in. This, in turn, determines whether the substance exists in the solid, liquid, or gaseous state. Molecules in the solid phase have the least amount of energy, while gas particles have the greatest amount of energy.
  • The temperature of a substance is a measure of the average kinetic energy of the particles.
  • A change in phase may occur when the energy of the particles is changed.
  • There are spaces between particles of matter. The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases.
  • There are attractive forces between atoms/molecules, and these become stronger as the particles move closer together. These attractive forces are called intermolecular forces. 

Click on this link to see a simulation of intermolecular forces from The Concord Consortium (2019)

Example: Water

Let's take water as an example. We find that in its solid phase (ice), the water molecules have very little energy and cannot move away from each other. The molecules are held closely together in a regular pattern called a lattice. If the ice is heated, the energy of the molecules increases. This means that some of the water molecules are able to overcome the intermolecular forces that are holding them in a lattice, and the molecules move out of their rigid structure, forming liquid water. This is why liquid water is able to flow: the molecules have greater freedom to move than they had in the solid lattice. If the molecules are heated further, the liquid water will become water vapor, which is a gas. Gas particles have more energy and are on average at distances from each other which are much larger than the size of the atoms/molecules themselves. The attractive forces between the particles are very weak given the large distances between them.

 

Now watch this video on phase changes and solids, liquids and gases: 

Media embedded September 28, 2019

                                                      Video from Tyler DeWitt, 2011

Comment: Answer one of the following questions in the comment section below. 

  • Describe the difference in the arrangement of particles in solids, liquids, and gases

  • Rank the states of matter from the least amount of energy to greatest amount of energy.

  • What is kinetic energy and how does it relate to temperature?

  • The temperature of the oven is a direct measurement of the heat. Is this true or false? Explain.

  • The text says “The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases.” Do you think this is always true? Can you think of an exception to this general rule?

Update: Record/ take a picture of a phase change at home. Draw a model of how the particles are arranged during that phase change. Comment on 3 other updates.

 

For the Teacher

In this update, students will learn the basics of Kinetic Molecular Theory, and the behavior of particles in solids, liquids, and gases. 

Standards and Instructional Objectives covered in this update: 

  • HS-PS1-7: Use mathematical representations of phenomena to support claims.
  • MP.2: Reason abstractly and quantitatively.
  • ES2: Use and construct models as helpful tools for representing ideas and explanations. These tools include diagrams, drawings, physical replicas, mathematical representations, analogies, and computer simulations.
  • Describe the arrangement of particles in solids, liquids, and gases.

Students will watch 2 short videos and read a selection of text. All of these resources focus on the behavior of particles in the different states of matter. They also focus on modeling the behavior of particles. Modeling particles helps students develop a deep understanding of how molecular behaviors affect the bulk properties of matter. 

After watching the videos and reading the text, students will then choose a question to answer in the comment section. These questions are designed to have the students apply the new information and think about the meaning of the text instead of just pulling facts from text. The teacher should read the comments and either respond or have a class discussion about their responses to ensure that all the questions were answered, and if there any misconceptions that they are clarified.  The last question in the prompt, "The text says “The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases.” Do you think this is always true? Can you think of an exception to this general rule?" often causes students to struggle and many of them have the misconception that particles in solids are always more tightly packed than particles in liquids.  At this point, you should make the students aware that water is an exception to this rule and that the molecules in ice are actually more spread out than the molecules in water. This explains how ice is less dense than water, and why it expands when frozen. 

Students are then asked to create an update where they record or take a picture of a phase change and then draw a model of the particles in that phase change. 

 

Update 2

For the Student

By the end of this update, you will be able to predict how a gas will behave in response to a change in temperature, volume, or pressure and calculate the change in pressure, temperature, or volume of a gas when 1 or more variables are changed.

Read the following text and take notes. You will complete a quiz on the concepts introduced in this text. 

Getting started: some handy terms you'll need to know

Before doing gas law calculations, you've got to figure out what all of the appropriate terms, symbols, and variables are. For those of you having trouble figuring it out, here are some of the more common ones:

ideal gas: An imaginary model of a gas that has a few very important properties. These properties are that the particles of the gas are assumed to be infinitely small, the particles move randomly in straight lines until they bash into something (another gas molecule or the side of whatever container they're in), the gas particles don't interact with each other (they don't attract or repel one another as real molecules do) and the energy of the particles is directly proportional to the temperature in Kelvins (in other words, the higher the temperature, the more energy the particles have). We make these assumptions because a) They make the equations a whole lot simpler than they would be otherwise, and b) Because these assumptions don’t cause too much deviation from the ways that actual gases behave.

kelvins: A temperature scale in which the degrees are the same size as degrees Celsius but where "0" is defined as "absolute zero", the temperature at which molecules are at their lowest energy. To convert from degrees Celsius to Kelvins, add 273. By the way, we don't say "degrees Kelvin", we just say "Kelvins". Go figure.

pressure: A measure of the amount of force that a gas exerts on whatever container you've put it into. Imagine a shaving cream can. When the pressure is very high in there, the gas in the can pushes very hard on the walls of the can, which is why the cans are made much stronger than soda cans. Units of pressure include atmospheres (1 atm is the average atmospheric pressure at sea level), Torr (which are equal to 1/760 of an atmosphere), millimeters of mercury (1 mm Hg is the same as 1 Torr, or 1/760 atm), and kilopascals (there are 101,325 kPa in 1 atm).

standard temperature and pressure: A set of conditions defined as 273 K and 1 atm.

temperature: A measure of how much energy the particles in a gas have. Units of temperature that you'll run into include degrees Celsius (which you shouldn't use when doing gas law calculations for reasons we'll talk about later) and Kelvins (which is equal to 273 plus the degrees Celsius).

volume: The amount of space that some object occupies. The unit of volume can be cubic centimeters (abbreviated "cc" or "cm3 "), milliliters (abbreviated "mL" - 1 mL is the same as 1 cubic centimeter), liters (abbreviated as "L" and equal to 1000 mL), or cubic meters (abbreviated "m3 " - there are one million cubic centimeters in a cubic meter).

Robert Boyle was a man with a dream. He wanted to be the first man to eat 100 hard-boiled eggs in a 24-hour period. Unfortunately, some of the other chemists got jealous - let's just say that considerable ugliness ensued and Boyle's dream was permanently derailed (this isn't actually true). However, Boyle was a man of many talents, and was able to come back from his humiliating egg fiasco to come up with a gas law of his own.

Here's what Boyle did: He put a gas into a container in which he could change the volume and measure the pressure. When he multiplied the volume of the gas times it's pressure, he found it was equal to some arbitrary number (let's call it k, because he did). If he changed the pressure of the gas, he found that the volume also changed, which isn't really surprising (if you push on something, it gets smaller). What is surprising is that if you multiply the new pressure by the new volume, the answer is the same arbitrary number that you had in the first place (k!). From this, we can make the following statement:                       

                                                             P1V1 = P2V2

In this equation, P1 is the initial pressure of the gas and V1 is the initial volume of the gas. P2 is the final pressure of the gas and V2 is the final volume of the gas. This way, if you know the initial pressure and volume of a gas and know what the final pressure will be, you can predict what the volume will be after you put the pressure on it. Let's see an example.

Question: If we have 4 L of methane gas at a pressure of 1.0 atm, what will be the pressure of the gas if we squish it down so it has a volume of 2.5 L?

Answer: Let's plug the numbers we've been given into the problem. Set up a table and fill in your given values and your unknown.

P1: 1.0 atm

V1: 4 L

P2: ?

V2: 2.5 L

When we put all of these numbers into the equation, we get:

P1V1 = P2V2

(1.0 atm)(4 L) = (P2)(2.5 L)

Then we need to solve for our unknown to find the new pressure.

x = 1.6 atm

Watch this video for an explanation of Boyle's Law:

Media embedded September 28, 2019

                                                         Video From Tyler DeWitt, 2008

Jacques Charles was a disturbing and scary guy. Though he came up with a really handy law for determining what the relationships between the volume and temperature of a gas are, his private life was far more bizarre. Some say that if you go by the old Charles mansion at the edge of town, you can still hear the moaning and wailing of his ghost, forever roaming the night(not really true).

Anyhow, what Charles determined through his studies was that when you change the temperature of a gas, the volume changes. Not surprising - you probably know already that if you heat something, it tends to get bigger. What he found, though, was that if you divide the volume by the temperature of a gas at one temperature, you get a constant. Just like Boyle found, if you change the volume or temperature of this gas, you get the same constant. From this, Charles came up with this statement:

Where the subscript "1" indicates the initial volume and temperature and the subscript "2" indicates the volume and temperature after the change. Temperature, incidentally, needs to be given in Kelvins and not in Celsius - this is because if you have a temperature below zero degrees Celsius, the calculation works out so the volume of the gas is negative, and you can't have a negative volume.

Let's see an example of this equation in action:

Question: If we have 2 L of methane gas at a temperature of 40 degrees Celsius, what will the volume be if we heat the gas to 80 degrees Celsius?

Answer: Create a table and fill in the given information and unknowns. Make sure to convert the temperatures to Kelvins (by adding 273) because Celcius can't be used in this equation.

V1: 2L

T1: 40o C +273 = 313 K

V2: ?

T2: 80o C =273 = 353 K

We're now ready to start sticking these numbers into the equation:

This video below shows you how to calculate using Charles Law:

Media embedded September 28, 2019

                                                      Video from Tyler DeWitt, 2008

 

There was a third guy whose gas law is a little less famous than the others. Some think it's because it has something to do with having a bad public relations firm working for him. Whatever the reason, his name is Gay-Lussac, and his law related pressure to temperature:

This gas law explains how if you increase the temperature of a container with fixed volume, the pressure inside the container will increase. This explains why you shouldn't leave cans of spray paint in your trunk - the pressure might get so high that the propellant will blow the can up.

REMEMBER… When solving these problems, always convert the temperature to Kelvin!!!

This video shows you how to use Gay Lussac's Law: 

Media embedded September 28, 2019

                                                 Video from Tyler DeWitt, 2010

 

Imagine a world in which you didn't need to memorize the three laws above. Instead, there was one big law that covered both of them. Hey, that's the world you live in now, and the law you need to know is the combined gas law:

In this equation, all of the terms are exactly the same as in the preceding equations. The way you can use this equation is that whenever you're changing the conditions of pressure, volume, and/or temperature for a gas, you just plug the numbers into this equation. However, let's imagine that the temperature of the gas didn't change while you were making your change. Since the first temperature term and the second are the same, they cancel out. As a result, if one of these variables isn't mentioned in the problem, just ignore it entirely. Let's see an example:

Question: If we have two liters of a gas at a temperature of 420 K and decrease the temperature to 350 K, what will the new volume of the gas be?

Answer: To solve this problem, use the combined gas law to find the answer. Since pressure was never mentioned in this problem, just ignore it.

P1: X

V1: 2 L

T1:420 K

P2: X

V2: ?

T2: 350K

Here is a video that walks through an example of how to use the Combined Gas Law:

Media embedded September 28, 2019

                                                    Video from Tyler DeWitt, 2010

What happens if you don't change the conditions of a gas, but just want to find out what a gas is like when it's sitting in a container, not doing much? Well, the equations above won't help you much, because they're equations which depend on making a change and comparing the conditions before the change and after the change to make determinations about what the gas is like.

The ideal gas law is an equation of state, which means that you can use the basic properties of the gas to find out more about it without having to change it in any way. Because it's an equation of state, it allows us to not only find out what the pressure, volume, and temperature are but also to find out how much gas is present in the first place.

Here it is:

                                                                        PV = nRT

Where P is the pressure of the gas (either in atmospheres or kilopascals), V is the volume (in liters), n is the number of moles, R is the ideal gas constant, and T is the temperature (in Kelvins).

There are two common values for the ideal gas constant. One of them is 0.0821\(L\space\ atm \over mol\space\ K\) , and the other is 8.314 \(L\space\ kPa \over mol\space\ K\)The question is, which one do you use?

The value of R used depends on the pressure given to you in the problem. If the pressure is given to you in atmospheres, use the 0.0821 value because the unit at the end of it contains "atmospheres". If the pressure is given to you in kilopascals, use the second value because the unit at the end contains "kPa".

Another good thing about this law: It allows us to figure out how many grams and moles of the gas are present in a sample. After all, "moles" is the "n" term in the equation, and we already know how to convert grams to moles. (remember molar mass!) Let's see an example:

Question: If I have 4 liters of a gas at a pressure of 3.4 atmospheres and a temperature of 300 K, how many moles of gas are present?

Answer: The first thing you need to do is figure out what value of the ideal gas constant should be used. Since pressure is given to you in atmospheres, use the first one, 0.0821

P: 3.4 atm

V: 4 L

n: ?

R: 0.0821

T: 300 K

The next two videos explain the Ideal Gas Law:

Media embedded September 28, 2019

                                                         Video From Tyler DeWitt, 2010

Media embedded September 28, 2019

                                                         Video from Tyler DeWitt, 2010

 

Comment: Ask any question you have on the material that you just learned. If you know the answer to any of the questions, help out your peers by responding and answering each other's questions.

Once you have read responded in the comments, take the knowledge survey. Use notes that you have taken while reading the update.

 

For the Teacher

In this update, students will learn the relationship between pressure, volume, temperature, and moles of a gas and the mathematical laws that describe the relationships. 

Standards and Instructional Objectives covered in this update:

NGSS Standards

  • HS-PS1-7: Use mathematical representations of phenomena to support claims.

Common Core Mathematics Standards

  • MP.4 Model with mathematics.
  • HSN-Q.A.1 Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.

District-Wide Essential Science Skills:

  • ES1: Use mathematics and computation as fundamental tools for representing physical variables and their relationships and for a range of tasks such as constructing simulations; statistically analyzing data; and recognizing, expressing, and applying quantitative relationships.
  • ES3: Use observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

Unit Instructional Objectives:

  • Predict how a gas will behave in response to a change in temperature, volume, or pressure.
  • Calculate the change in pressure, temperature, or volume of a gas when 1 or more variable is changed.
  • Calculate pressure, volume, temperature, or moles using the Ideal Gas Law Equation

This section is very long and should be completed over a few class periods or longer depending on how much support your students need with algebra. Teachers can supplement this section with various practice problems to help the students calculate using the Gas Laws. 

The videos that were included were all done by Tyler DeWitt. Tyler DeWitt is a popular digital content author and the creator of one of the most popular educational channels on YouTube.  He is well known for his effective communication of chemistry concepts in easy to understand language.  Students like his simplified language and find his videos very easy to understand, which is why I included them in this update. 

At the end of the update, students should write their questions or comments about any part of the material. Encourage students to answer each other's questions to create a learning community where they can support each other. After they have had time to ask and answer questions, the students should take the knowledge survey to show their understanding of the Gas Laws. 

 

Update 3

For the Student

By the end of this update, you will be able to create a model that shows how particles behave when there is a change in pressure, volume, or temperature. 

In this update, you will be using a simulation to illustrate the relationships between pressure, volume, and temperature at the particulate level. 

Go to the PhET Gas Properties Simulation at this link.

Choose Explore.  You should see the simulation pictured here: 

ScreenShot from PhET Gas Properties Simulation available at https://phet.colorado.edu/sims/html/gas-properties/latest/gas-properties_en.html

When you first open the simulation, take about 10 minutes to explore how the sim works. Change different variables and settings. 

As you learned in the previous update, Boyle's law, Charles' Law, and Gay Lussac's Law showed the relationship between only two variables. It is easier to study relationships if only two parameters are varied at a time and the others are all held constant. 

Use the simulation to explore how the particles in a gas behave for each of the three laws.  Create a data table similar to the one pictured here to help you organize your thoughts. Pay particular attention to the motion of the particles and the number of collisions during your observations. 

Create an update: Find a real-life example of a gas law.  Describe the even and then create a model that describes the behavior of the particles during the example.  Once you create your model, take a picture and include it in your update. 

Comment on 2 other students' updates. Could the example be explained a different way or with a different gas law? 

 

For the Teacher

In this update, students will observe how the behavior of particles in a gas explain the relationships described in the gas laws. 

Standards and Instructional Objectives covered in this update:

NGSS Standards

  • HS-PS1-2: Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

Common Core Mathematics Standards

  • MP.2: Reason abstractly and quantitatively.

District-Wide Essential Science Skills:

  • ES2: Use and construct models as helpful tools for representing ideas and explanations. These tools include diagrams, drawings, physical replicas, mathematical representations, analogies, and computer simulations.

Unit Instructional Objectives:

  • Predict how a gas will behave in response to a change in temperature, volume, or pressure.

In this update, students are exploring a simulation that shows how the particles in a gas behave when pressure, temperature, and volume behave. Students then are asked to apply what they have learned to phenomena that they have experienced in their own lives and create a model to explain how the particles are behaving in that example. 

Common real-life examples of gas laws could be: 

  • tires becoming flat in the winter
  • bags of chips inflating when in an airplane
  • hot air balloon inflating and rising
  • spray cans exploding when heated

Students should be encouraged to find their own example to use and, if safe and possible, to demonstrate and record the change to include in their update. 

Once students have posted their example, students should comment on each other's posts if they can think of a different way of explaining the example.  Often, real-world examples of gas laws can be explained with multiple gas laws, each being a correct explanation. This forces students to think of all of the different variables that are changing during the examples. 

Update 4

For the Student

By the end of this update, you will be able to perform a demonstration to the class that illustrates a gas law. 

For this update, you will create a presentation that illustrates one of the topics we have been studying including: 

  • Boyles’ Law
  • Charles’ Law
  • Gay-Lussac’s Law
  • The combined gas law
  • The ideal gas law
  • Kinetic theory (of gases)
  • Phase change (melting, evaporating, freezing, sublimation)

For this presentation, you will need to perform a demonstration live for the class, or record a video to be played to the class. Don't be afraid to be creative in your presentation. 

With your presentation, you should include an explanation of the demonstration in writing along with 2 discussion questions.  

You should be able to find demonstrations that are safe and appropriate to do in the class by searching for classroom gas law demonstrations. You must plan ahead and get your demonstration approved and provide me with a list of your needed supplies. 

Create an update: Upload a recording of your demonstration and include it with your written explanation and 2 discussion questions. 

Comment: Respond to your classmate's discussion questions in the comment section of their updates. 

 

 

For the Teacher

In this update, students will give a demonstration to the class that illustrates one of the topics they have learned. 

Standards and Instructional Objectives covered in this update:

NGSS Standards

  • HS-PS1-2: Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

District-Wide Essential Science Skills:

  • ES2: Use and construct models as helpful tools for representing ideas and explanations. These tools include diagrams, drawings, physical replicas, mathematical representations, analogies, and computer simulations.
  • ES4: Investigate and explain causal relationships and the mechanisms by which they are mediated. Can use relationships of cause and effect to predict and explain events in new contexts.
  • ES6: Use skills of collaboration, creativity, critical thinking, and communication to design, execute, and communicate scientific investigations.

Unit Instructional Objectives:

  • Predict how a gas will behave in response to a change in temperature, volume, or pressure.

In this update, students should work in small groups to prepare a demonstration to be performed for the class.  Chemistry teachers often perform demonstrations to classes to illustrate ideas and concepts being taught to the class, but this switches the roles and has the students performing the demonstrations for each other. THis allows students to gain a deeper understanding of the concepts through researching and developing a way to explain the concept to their peers.  

By creating discussion questions and answering each other's questions they are contributing to the class knowledge. 

If students struggle to come up with demonstrations, you could suggest they search one of the following: 

  • Cartesian Diver
  • Balloon in a Flask
  • Charles' Law and Rising Water
  • Can Crusher
  • Marshmallows in a syringe
  • Hot air balloon with a plastic bag

 

Update 5

For the Student

By the end of this update, you will conduct a short research project to determine the effect of changing variables to demonstrate an understanding of the subject under investigation.

For this activity, you will be conducting research, designing and carrying out a lab investigation, and creating a project proposal to a fictional recycling corporation, CanCo. The project description is below.  

​                                                             CanCo Project Proposal

 

CanCo is looking to hire a scientific community that can prove that they are able to effectively and efficiently solve our technical research problems. Your task is to solve the problem outlined below and give a presentation to the company representative on the assigned deadline. Your teacher may act as a consultant while you perform your experiments, but may not be able to answer all questions.

Technical Problem: CanCo wants to combine the cleaning and crushing operations at our plant. We have found that we can both clean and crush a can by putting some water into it, heating it, and turning the can into a bath of tap water. We are looking to install a robotics system that would do this operation, but we need to know the following:

  1. What variables affect the amount of can crush (i.e. the initial can volume minus the final can volume)?
  2. How does each of the variables listed in #1 affect the amount of can crush?
  3. What conditions should we set for the process to obtain the maximum crush?
  4. Is the process (with your proposed conditions from #3) reliable enough to always give at least 75% volume crush on all cans? Provide enough data to support your claim.

Your quality presentation: Due to the representative’s limited time, your presentation of results will be limited to a maximum of five minutes. Your presentation needs to concisely answer the four questions outlined above (think about “effective communication” when preparing). On the date of your presentation, you will be required to share your presentation and written lab report to your teacher that will send it to the company. Your team will be competing against other teams for our future business. Because this presentation is important, your group will be in charge of peer-reviewing 2 other group presentations and written reports. You will then have an opportunity to revise your presentation before you present it. 

You will have the lab for 2 days. You are in charge of this project- make sure you have planned and are prepared by bringing in any necessary materials not found in the lab.

You can use this planning document available at this link to organize and plan your experiment. 

Your team will be competing against other teams for our future business. Because this presentation is important, your group will be in charge of peer-reviewing 2 other group presentations and written reports. You will then have an opportunity to revise your presentation before you present. 

 

 

 

 

 

For the Teacher

By the end of this update, students will be able to conduct a short research project to answer a question; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, to demonstrate an understanding of the subject under investigation.

Standards and Instructional Objectives covered in this update:

NGSS Standards

  • HS-PS1-2: Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

District-Wide Essential Science Skills:

  • ES2: Use and construct models as helpful tools for representing ideas and explanations. These tools include diagrams, drawings, physical replicas, mathematical representations, analogies, and computer simulations.
  • ES4: Investigate and explain causal relationships and the mechanisms by which they are mediated. Can use relationships of cause and effect to predict and explain events in new contexts.
  • ES6: Use skills of collaboration, creativity, critical thinking, and communication to design, execute, and communicate scientific investigations.

Unit Instructional Objectives:

  • Use valid reasoning, good judgment, and systems thinking to form ideas or solve problems.
  • Conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating an understanding of the subject under investigation.
  • Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.

This project is adapted from the book Whole-Class Inquiry: Creating Student-Centered Science Communities by Dennis Smithenry and Joan Gallagher-Bolos . 

In this project, students work together to develop a lab that tests two different variables to alter how much they can cause a can to crush when moving from a hot-plate to ice water. This demonstration is useful to have students examine because it can be explained by multiple gas laws and there are many opportunities to change the conditions to create more or less crush. 

Students will evaluate each other using a one-point rubric, which is common in our school. With the one point rubric, the requirements of the project are listed but it is up to the students to develop their own way to excel in each criterion. 

Students should have at least 2 days in the lab for testing, along with 2-3 days to work with their groups to create the report and presentation. 

The rubric for the project is below: 

 

Update 6

For the Student

By the end of this update, you will have presented your project proposal and the class will have voted on the presentation that is awarded the contract. 

Now that you have created a proposal, received feedback and modified your presentation and report, it is time for your final proposal. Your group may present live to the class, or you may submit a video of your presentation. 

After all the presentations are complete, the contract will be awarded. 

Comment:  In the comments, reflect on what you learned from this project.  Include information that you learned by designing and completing the lab, the peer review process, presenting your project, or listening to others. 

 

For the Teacher

In this update, students will be presenting their final proposal to the class.  

Standards and Instructional Objectives covered in this update:

NGSS Standards

  • HS-PS1-2: Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

District-Wide Essential Science Skills:

  • ES6: Use skills of collaboration, creativity, critical thinking, and communication to design, execute, and communicate scientific investigations.

Unit Instructional Objectives:

  • Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.

For the presentations, groups can either present live to the class or if they are not meeting in person, they can submit a video to be reviewed by the class. 

The goal of this presentation was to win a "contract" with the recycling company, so there should be a winner declared at the end. There are multiple options as to how the teacher might award the winner. If possible, an outside person should come into the class to make the ratings. This makes the task seem more real and objective.  

Other options could be a class vote where students are allowed to vote for another group to determine the winner or the teacher can award the contract themselves. 

For their final comment for the unit, students should reflect on their learning that occurred during the project. They should be encouraged to look at what they learned throughout the entire process, including the designing of the lab, the writing of the report, the peer-review process, the presentations, and listening to each other. 

 

 

References


DeWitt, T. (2008, July 31). Charles' Law. Retrieved from https://www.youtube.com/watch?v=oIfFoiwRCVE.


DeWitt, T. (2008, July 31). Boyle's Law. Retrieved from https://www.youtube.com/watch?v=ZoGtVVu3ymQ.


DeWitt, T. (2010, November 4). Gay Lussac's Law Practice Problems. Retrieved from https://www.youtube.com/watch?v=wHD-32rUHkE.


DeWitt, T. (2010, July 31). Combined Gas Law. Retrieved from https://www.youtube.com/watch?v=bftkRnTcFj8.


DeWitt, T. (2010, November 8). Ideal Gas Law Practice Problems. Retrieved from https://www.youtube.com/watch?v=TqLlfHBFY08&list=PLz8VX_lVZkWcGZr61LHEkAS_hXbbAsIHo&index=5.


DeWitt, T. (2011, October 6). Phase Changes. Retrieved from https://www.youtube.com/watch?v=EZHmUTmJtF8.


PhET Interactive Simulations. (2019, September 19). Gas Properties. Retrieved from https://phet.colorado.edu/en/simulation/gas-properties.


ScámarcaProductions. (2016, May 24). The Kinetic Molecular Theory (Animation). Retrieved from https://www.youtube.com/watch?v=1Jtw8g795Us.


Smithenry, D. W., & Gallager-Bolos, J. (2009). Whole-class inquiry: creating student-centered science communities. Arlington, VA: NSTA Press.


The Concord Consortium. (n.d.). Intermolecular Attractions and States of Matter. Retrieved from https://lab.concord.org/embeddable.html#interactives/sam/phase-change/5-interatomic-interactions-and-states.json.