Making Models to Build Knowledge

I needed a hands-on model that I could quickly assemble with articles found in the lab. A quick look through my cabinets yielded just such items: different colored marbles, an aluminum dish, and assorted other small items. But what about the electrons? Could I find something that could also help visualize the idea that the electrons are smaller and of much less weight than the protons/neutrons. Paper hole punches! Soon each table was equipped with the makings of an atomic model for every pair of students.

Almost immediately regret over the decision to select marbles settled in. The irritating sound of ricocheting marbles filled the classroom as students succumbed to the irresistible urge to repeatedly drop a marble from their hand onto the table allowing it to reverberate across the epoxy resin surface of the work space.  Clearly, there was no ill-will on the part of the students as they simply “needed” to handle those marbles. So, we carried on. Somehow students were simultaneously listening to instruction and were eager to assemble the atomic models as the theory was introduced. Dropping “neutrons” and “protons” into the “nucleus” was easy but they questioned how they should place the electrons outside the nucleus. Instinctively, they didn’t want to just drop their paper circles by the side of the dish. The concept of energy levels organically became part of our discussion and the students seemed relieved to have direction as to how to order their electron around the nucleus. Great care was taken to properly place their electrons.  Chatter about atoms was filling the classroom.

Later in the unit students easily built isotopes with this same model. They could visualize how the isotope carried the same charge and proton number as the “regular” atoms but that their mass was different. It was easy to accept that these isotopes, because of their varying masses, might have different physical properties and characteristics.

The same models were employed to make cations and anions by adding and removing electrons as the unit moved into ions. Students could easily visualize how charge became negative when electrons were added and positive when electrons were removed.

This same model provided variety to lessons, hands-on learning, and additional review as we built on the students’ understanding of the atomic theory. The models became a familiar tool in the classroom and as they sat before the students,  the marbles were heard ricocheting less and less across the tables. Just like with a beaker or graduated cylinder, the students began to handle the models as a simple piece of equipment required to accomplish a task, in this case, the task of mastering atomic theory.

Keep it simple! No fancy kits need to be ordered to provide our students with hands-on activities. Often things we have lying around can serve the purpose. The rewards include a buzzing classroom and student achievement.

Uncomplicated but poignant activities

It was a simple idea. It’s possible they’ve even done it before in another class sometime during their education. However, I knew they would learn from it and would thereby approach the learning objectives. So, I prepared the materials.

The instructions, accompanied by an image, were simple: build a model of the ventilation system. The building part was easy and fun. With their hands and minds engaged, they were hooked and as the more challenging part of the activity faced them, they plowed ahead. With the expectations for the write-up in front of them, they reached for the models again and again, seeking deeper understanding. They discussed. They questioned. They pointed. They pulled.


“Oh, I get it” followed by an explanation of the role of air pressure in breathing.

“So, when the diaphragm contracts, the thorax expands.”

“The intercostal muscles are located here and contract and expand with the diaphragm”

Soon everyone in the room can accurately and biologically describe inspiration and expiration. And all it took were some plastic bottles and balloons.

VALUE the power of simple.

Later in the day the health teacher and I were comparing curriculum since we share students who are doing a unit on the respiratory system in both health and biology. He began to describe an activity he had completed with the students and then hesitated, “Oh, it was nothing. It was so simple” he says, almost discrediting the activity because it was simple. “The students were handed a straw and told to run up and down the stairs using only the straw with which to breathe in and out.  He continued, “But they really got it. As they came up the stairs, they described feeling panicked, even though they knew they could remove the straw. Suddenly they had a real idea as to what it would mean to have emphysema."

Today as we continued our learning about the structures of the ventilation system, I asked those same students about what would happen if the airways were constricted. They immediately piped in what they knew about emphysema. They added their experience in the stairways and I asked them what they learned from that. The response was unanimous, “Now I know how it might feel like to have emphysema.” And all it took was a straw.

VALUE the power of simple.

Recently a colleague came to me and said, “I think I need to change the way I teach. I’m too lecture based and I need more activity driven lessons” and then she followed up with an overwhelming description of what that might look like. She had grand but complicated ideas that would require hours of prep time, a luxury she does not have.  “Simple goes a long way” was my advice. “What do you mean?” she queried. “Look at this gap activity – students simply matching concepts with descriptions” but it engages them. We brainstormed a bit and she came up with a brilliant idea. In fact, it’s so brilliant that I’ll be borrowing and reporting on it someday! She ran back to her room and produced the activity in about ten minutes.  And all it takes is a story problem and a stack of paper cut-outs with words to enable hands-on, engaged processing of the problem.

VALUE the power of simple.

Be empowered by uncomplicated ideas. Think outside the box but look inside the box (i.e. your classroom) for your supplies.