Changing States of Matter Lab

Our Changing States of Matter Lab offers a firsthand visual of how adding thermal energy to a state of matter can cause it to change to a different state. To coincide with this lab, be sure to check out our Changing States of Matter Activities and our other States of Matter Printables which will help to solidify states of matter and their properties. These resources were created with middle school students in mind, but could be used for a multitude of ages. This lab uses simple tools and materials for a relatable visual for students.

*Be sure to check out our other Homeschool Science Resources including our Floating Egg Lab Experiment!

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Implementing the Changing States of Matter Lab

Print FREE Changing States of Matter Lab Sheet

Do you need the lab sheet to do the demonstration? No. The lab sheet is there to help keep structure in your class and to add an element of comprehension. Students are more likely to recall how the energy level and molecule movement increases or decreases if they write about it. There is just something about writing that helps students to retain information. Download Changing States of Matter Lab Sheet below!

Start with a pot of ice

We used a pot since we were doing the lab investigation at home. We added just enough ice to fill the bottom of the pot. I let the kids touch the pot before putting it on the eye of the stove. This way my students could feel how cold it was. We talked about the absence of thermal energy… heat. Heat can be measured by temperature. The higher the temperature, the more heat. Heat can also be described as thermal energy. This is a great time to talk about how the molecules within the ice are arranged. In this case, the molecules are tight and arranged in an orderly fashion with low energy.

Next add thermal energy to produce liquid

Now it is time to add some thermal heat by turning on the stove top. If you put the eye on high, it is amazing to see how quickly the solid ice begins to melt. We discuss how with the increase in thermal energy, there is an increase in energy within the state of matter. The molecules begin to move and slip past each other turning into liquid water. This process is called melting.

Add more thermal energy to produce gas

Continue to observe as the liquid water begins to evaporate into vapor. The steam can be seen rising from the pot. As the energy in the liquid increases, the molecules begin to spread out even more and with not being able to contain their energy level, they turn into a gas floating away. This is a great time to talk to your students about how in each of these processes, melting and evaporating, energy is entering the state of matter. This is called an endothermic change. If the processes were opposite and energy was leaving the state of matter, then that would be described as an exothermic change. For example, in condensation gas loses energy to turn into liquid water. The energy exits the state of matter to change to a new state.

Discuss Endothermic and Exothermic Change

This is a great time to talk to your students about how in each of these processes, melting and evaporating, energy is entering the state of matter. This is called an endothermic change. If the processes were opposite and energy was leaving the state of matter, then that would be described as an exothermic change. For example, in condensation, gas loses energy to turn into liquid water. The energy exits the state of matter to change to a new state.