Energy and Matter is one of the most challenging Crosscutting Concepts for students and teachers. Read this post to get the anwers you need.
Energy and Matter: An Overview
This Crosscutting Concept is pervasive across science disciplines and the Next Generation Science Standards. Let's start with the basics and make sure that we have a clear understanding of both of these concepts.
What is matter?
Matter is simply the stuff that makes up everything around us. It makes up everything that takes up space and has mass. For example, a building, a person or, a chair and even stars are all made of matter. Nibbles, my cat seen in the image below, is made of matter.
What is matter made of?
Particles make up matter. And particles are teeny tiny pieces of matter. These definitions become more clear when you look at the progression of this Crosscutting Concept from kindergarten to high school.
To view this progression, take a look at this post from NSTA. It shows what students should be thinking about in each grade level band.
When do students learn about particles?
In early elementary, students explore the idea that matter can be broken into smaller parts. When I think about this, I think about crumbs. Crumb are tiny pieces of larger things like cookies. And, these crumbs can be very, very small. In fact, they can be so small that they are difficult to see.
Students first learn about particles and their behavior in 5th grade. Check out the evidence statement for performance expectation 5-PS1-1 here to learn more about this standard.
Conservation of Matter and Mass
Mass is a measure of the total amount of matter that is in an object. In upper elementary, students learn that matter can be tracked in terms of weight. When there is a change in weight, there is also a change in the amount of matter that is present.
However, matter can't be created nor destroyed. Therefore, students are able to use this concept to track where matter is going.
Let's take a look at Nibbles again to see how this concept applies to the real world. Here is a picture of her as a kitten. As you can see, she was much smaller than she is now.
As she grew, she also gained weight. This means that she is now made of more matter. But where did all of this additional matter come from?
Nibbles is a healthy eater and obtained her additional matter and mass by eating kitten food. This shows that the old saying that “you are what you eat” is absolutely correct. Often, students observe growth but don't directly correlate this to the food that is consumed building their own biomass.
Middle School and High School Progression
In Middle School, students learn that the total number of particles in a chemical reaction stays the same. In prior standards, this was taught as balancing equations. However, middle school students are not required to know how to balance an equation. Still, a simple balanced chemical equation can serve as a model that demonstrates the conservation of particles.
In high school, especially in later years, students learn about nuclear reactions. In this case, the number of atoms does not stay the same. However, the Crosscutting Concept of Energy and Matter in the High School grade band states that in these nuclear processes “the total number of protons plus neutrons is conserved”.
What is the difference between weight and mass? When should students start using the term mass?
Most people use these term interchangeably. On Earth, mass and weight are essentially the same. However, gravity affects the weight of an object. Because the gravitational force on different planets varies, so does the weight of an object.
Nibbles has a mass of 4.5 kg on Earth, Mars, or anywhere else in the universe. However, if Nibble were able to fly to the moon, her mass would only be 0.74 kg. This is because there is less gravitational force on the moon.
Calculate your own mass on the moon using this website.
According to the 5th grade standards, students don't need to fully understand the difference until after 5th grade. The assessment boundary for the 5th-grade standard states that the assessment does not include distinguishing mass and weight.
What is energy?
Energy is the ability to do work. However, I dislike this definition because it doesn't encompass the many forms that energy takes in the minds of students. Instead, I define energy as the ability to do anything. Here are just a few of the many things that energy can do:
- Create sound
- Heat a room
- Move Objects (even small ones like particles)
- Make Electricity
What is conservation of energy?
Energy takes many form. For example, thermal energy (heat), light and electricity are all types of energy. The law of conservation of Energy states that energy isn't created or destroyed.
The law of conservation of energy states that energy isn't created or destroyed. Instead, energy can be transferred from one location to another or it can change forms.
What is the relationship between matter and energy?
Energy is a property of matter. Objects that have matter (all objects) also have energy. The amount of energy in an object can be measured in multiple ways. For example, it is often tracked at heat and temperature. Changes in temperature are often used to track the flow of energy.
Energy and Matter – Connection to the Crosscutting Concepts and Science and Engineering Practices
Energy and Matter and Systems
This Crosscutting Concept is also related to the concept of Systems and System Models. Starting in Middle School, students learn to discuss the flow of energy and matter into and out of and within a system. Also, students learn that the transfer of energy is responsible for the motion of matter.
Within a natural system, the transfer of energy drives the motion and/or cycling of matter.
Energy, Matter and States of Matter and Cause and Effect Realtionships
In Upper, students investigate states of matter. As an object gains energy, the particles that make up the object move faster. As a result, the state of the object changes. When particles start to flow freely, the object changes from a solid to a liquid form. As the energy increases further, the particles bounce off of each other and move farther apart. The state changes from a liquid to a gas.
Changes in energy and the flow of matter explains many cause and effect relationships in science. If students have difficulty making connections to the CCC of energy and matter, exploring Cause and Effect relationships can be a good way to make these concepts more accessible.
Scale, Proportion and Quantity
Students from Kindergarten through High School explore matter at different scales. In early elementary, students explore this concept at the visible level. Then, in 5th grade, students explore matter at unobservable scales.
Science and Engineering Practice Related to Energy and Matter
Energy and Matter is most easily relatable to the following Science and Engineering Practices of Developing and Using Models and Analyzing and Interpreting Data. However, it can also be use with all of the other practices.
For examples, this SEP of Developing and Using Models can be used to help students discuss and explain the flow of energy and matter within a system. Also, analyzing and interpreting data by tracking changes in temperature and mass can be used to track the flow of matter and energy.
Energy and Matter Resources
The PhET States of Matter Simulation, created by the University of Colorado, Boulder is an excellent resource. It helps students to see the relationships between energy and matter.
I recommend using this resource in 5th grade. Here is my write up for fifth grade students. It is a great way to help students understand what is happening at the particle level after they have been given the opportunity to explore and the visible level.
However, like many of the PhET simulation, it includes very simple and more complex features. In fact, I often used this simulation in my high school chemistry courses. The simulation includes phases change diagrams which allow students to explore the relationship between temperature and pressure.
I have also created reference sheets and graphic organizers for each of the Crosscutting Concepts. The reference sheets explain what the Crosscutting Concept looks like at each grade level band. This reference sheet can be kept in a digital or physical notebook so that students can refer back to it each time they encounter the Crosscutting Concept of Energy and Matter.
The Graphic Organizer helps students to make connections between the content, or the disciplinary core idea, and the Crosscutting Concept. It is currently available for upper elementary and middle school.
This resource is a great scaffold for students. But also, it is a great resource for teachers. By using this resource, teachers see what the concept should look like in a specific grade level band.
Here are some other resources that might be helpful. Check them out.