A Matter of States

Many children’s books and curricula about the states of matter begin by telling children the meaning of the terms solid, liquid and gas. But what if we didn’t start that way? What if we gave students examples of these materials and let them develop their own definitions through hands-on experimentation and observation? Even though we couldn’t know exactly where the exploration would lead, this is exactly what my partner teacher and I decided to do with our class of 3rd and 4th graders. We wanted them to take action and build their own understanding of how the world works, a key feature of constructivist learning.

At Sycamore, we like to start our units with a “big question.” In this case we began by asking “What is the world made of?” Students discussed their ideas and then developed their own related questions.

From there, we dove right into our investigation. We decided it would be easier to start by comparing solids and liquids first and then come back to gases later. We put out three solids (a nail, a rock, and an ice cube) and three liquids (water, liquid soap, and syrup) for them to study. We discussed how to observe these materials closely and had each student write descriptions and make detailed drawings in their science journals.

After this first experience, we observed that our students needed more practice writing definitions as most of them had just written adjectives like “hard” or “firm” for the solids, and “runny” or “wet” for the liquids.

We spent some time with the dictionary, and then we played a game that required each person to write a definition of a well-known object for the rest of the class to try and guess. We asked the students to think critically about whether their description would be true for all items in the category. For example, for pizza, one student had included that “it has pepperoni on it.” We asked her, “Could it still be pizza without pepperoni on it?” Asking students to be skeptics of their own work helps them improve their precision.

After they learned how to write more thorough definitions, we asked them to try again. This time, their explanations were far more detailed, but still contained some inaccurate or superfluous information.

We decided it was time to give them additional materials to explore in order to help them tighten up their work. We let the students spend some time trying to pour different solids (blocks and nails) and liquids (water and syrup) between two cups to see how they reacted. This sparked a completely new question: How do solids and liquids act differently when they are in containers?

It also added a whole new dimension to their writing.

Students completed one more draft on their own, and then we had them partner up so they could work collaboratively. They shared their work, and spent time asking each other questions. Finally, they wrote a definition together that combined the best elements of each one.

Our students continued to observe real-life examples such as water moving between two syringes. We also let them explore water in all three of its states: ice, water and steam.

After each team reflected on these new experiences, they were able to make changes to their joint definitions. Then we had each partnership come together with another so that four students could go through the same review process, and compose a final version for their whole group. This was challenging, but we talk to our students frequently about the value of sharing your own ideas, while being adaptable enough to consider the ideas of others.

The last step was to take all of the group definitions for solid and liquid and make them into one final class definition. Everyone was really excited to work on this step, as it was an extension of the personal and peer editing we do during Writers’ Workshop. Each student gave their input, and through this process we boiled it down into one succinct statement for each:

Solid: A hard or soft object that you can hold. It will not take the shape of what contains it. A solid is something that has length, width and height.

Liquid: If you pour a liquid, it will level out. You can run your hands through it. A liquid can take the shape of whatever contains it.

Our students were really proud of all their hard work, and were able to reflect on the benefits of experimentation and writing many iterations. They also developed a very complete and robust understanding of the scientific meanings of solid and liquid.

We are now continuing to explore the definition of a gas. Although not yet complete, a highlight of this part of the process has been our exploration of dry ice.