Learners put together everything they have covered about matter and energy and arrive at the definitive test for telling them apart. Students have already sorted everyday objects into categories, learned the three states of matter, discovered that energy makes things move and change, and practiced asking why. This lesson gives that prior knowledge a formal scientific structure: a three-attribute framework that works as a real test, not just a definition. By the end, students can apply that test to things that seem simple and to things that are genuinely tricky, including air, fire, sound, and magnetism, and explain their reasoning at each step.

Key Ideas

• Matter and energy are two completely different categories. The difference is not just about how things look or feel but about whether they pass three specific tests.
• The three-attribute test for matter: Does it take up space? Does it have mass (weight)? Can it be picked up or contained? Matter passes all three. Energy fails at least two.
• Energy is defined by what it does, not what it is. It makes things move, heat up, or light up. Energy cannot be weighed, picked up, or put in a box.
• Some things seem confusing at first. Air is invisible but takes up space, has mass, and can be contained. It is matter. Sound makes things vibrate but has no mass and cannot be picked up. It is energy. The three-attribute test resolves both.
• Adding or removing energy from a piece of matter does not change its mass. A balloon full of air weighs more than an empty one because of the extra matter (air) inside, not because of the energy used to inflate it.

Vocabulary

• Matter: Anything that takes up space and has mass. All solids, liquids, and gases are matter.
• Energy: Something that makes things move, change, or happen. Heat, light, sound, and electricity are forms of energy, not matter.
• Mass: The amount of matter in an object. Mass stays the same no matter where you are.
• Volume: The amount of space something takes up.
• Three-attribute test: The scientific check used to determine whether something is matter: Does it take up space? Does it have mass? Can it be picked up or contained?

Discussion Questions

• If you could weigh a beam of sunlight, what do you think you would find? How does that answer connect to whether light is matter or energy?
• Fire produces heat and light and seems to have a shape. Does fire pass the three-attribute test? Walk through each attribute one at a time.
• A shadow has a shape and moves when you move. Is a shadow matter or energy, or neither? How do you know?

Hands-On Activity: The Balloon Mass Test
Students test whether air has mass by comparing the weight of an inflated balloon to a deflated one. This is a demonstration of the three-attribute test in real time.

Supply List

• Two identical balloons
• A simple balance or kitchen scale
• A ruler or tape measure (optional)
• A notebook and pencil

Instructions

• Hold one uninflated balloon in your hand. Describe it: does it have any mass? Does it take up much space?
• Blow up the second balloon fully and tie it off. Hold it next to the deflated one. What changed? What stayed the same?
• Place both balloons on the scale or balance. Which side is heavier?
• Discuss: both balloons are the same rubber. The only thing added was air. Air has mass. That is what made the difference.
• Now apply the three-attribute test to air itself. Does air take up space? (Yes, the balloon expanded.) Does air have mass? (Yes, the filled balloon was heavier.) Can air be picked up or contained? (Yes, it is inside the balloon.) Conclusion: air is matter.
• Extension: what would happen if we repeated this with a balloon filled with light instead of air? Why is that impossible?

Hands-On Activity: Trying to Store Light in a Jar
Students test whether light can be contained the way matter can. This demonstration directly compares what happens when you close a container full of air (matter) versus close a container full of light (energy).

Supply List

• A clear jar with a lid
• A flashlight or phone light
• A dark room or closet (or a cardboard box that can be closed)
• A notebook and pencil

Instructions

• Go into a dark space or use the cardboard box. Shine the flashlight inside the jar. The jar is full of light right now. Put the lid on quickly.
• Open the jar in the dark. Is the light still there?
• Discuss: the moment you put the lid on, the light source was cut off. The light did not stay in the jar. Compare this to air, which stays in the jar when you close it because air is matter.
• Apply the three-attribute test to light: Does light take up space? (No, it cannot be sealed inside.) Does light have mass? (No, an empty jar and a jar full of light weigh the same.) Can light be picked up or contained? (No.) Conclusion: light is energy.
• In your notebook, draw a two-column chart. Label one column Matter and the other Energy. Add air and light to the correct columns with one piece of evidence for each.
  
  

Hands-On Activity: Tricky Edge Cases
Students apply the three-attribute test to genuinely confusing examples. The goal is not to memorize answers but to practice using the test as a tool and to discover that some things that seem like matter turn out to be energy, and vice versa.

Instructions

• For each item below, apply the three-attribute test out loud before reading the explanation. Decide first, then check.
• Sound: Does sound take up space? Does it have mass? Can it be picked up or contained? (Sound is vibrations traveling through matter. It cannot be weighed, sealed in a jar, or picked up. Sound is energy.)
• A shadow: Does a shadow take up space? Does it have mass? (A shadow is an absence of light. It has no mass and cannot be contained. A shadow is neither matter nor energy in itself. It is the result of light being blocked.)
• Electricity: Does electricity take up space? Does it have mass? (Electricity is the movement of electrons through a conductor. The electrons are matter. The movement is energy. Electricity itself is a form of energy, not a separate substance.)
• Magnetism: Can a magnetic force be weighed or contained? (Magnetism is a non-contact force. You can weigh a magnet, which is matter. But the magnetic force itself has no mass and cannot be put in a box. Magnetism is a form of energy.)
• After going through all four, add each one to your chart from the previous activity. Write one sentence of explanation for each.