Big Ideas for Little Kids: Molecules in Preschool

Stream of Consciousness Teaching: Who loves building with blocks? Who loves the Block Center? Me too. I love building at the block center. Of all the things you can build, what’s your favorite thing to create with building blocks?

I’m hearing so many great answers. But what if we wanted to build something real and alive? Like a person or an animal or a tree that we can plant outside and watch it grow? Can we use building blocks for that? Or do we need something else?

Well, since real trees aren’t made out of LEGOs or wood blocks or soft blocks or bricks, I think we need to think bigger. Have you ever seen a Wood Block Tree? I don’t think I ever have. What are trees made of?

Bark, leaves, branches, sticks, wood, seeds, roots, dirt — Yes! And if we wanted to get some of these tree parts — the bark and leaves and sticks and wood and dirt — where would we go?

Outside, right! And when we go outside, we go into nature. That means we want to find the building blocks that make up nature, right?.

So does that mean that bark and leaves and branches and wood and dirt — that they’re all parts of nature? Are those the building blocks of nature?

They are? Okay. So you’re saying that if we want to build a tree, we can’t use our regular building blocks in the block center. We have to build using nature’s building blocks, is that what you’re telling me? Okay, I think I get it. Y’all really know your stuff.

So, we know how to build a tree. We’ve got all our parts and we’re ready to build. But before we do, I wonder if we can go a little smaller. What do you think? Should we build something a little smaller than a big, giant tree to get started?

What if we want to build a leaf?

What are the building blocks of a tiny little leaf?

I don’t know, it’s pretty small already. And a leaf is only one part — I don’t see any tiny parts that you can put together to make a leaf. Do you? Hmm, I’m kind of stumped.

Maybe if we look closer, we can see tiny parts that will help us build a leaf. What can we use to look really up-close and see if there’s any tinier parts to this leaf? Do we have a tool that lets us see things super-duper-up-close?

Yes, we have magnifying glasses! We also have microscopes. “Micro” means super-duper, really, really, REALLY small. Do you think we will find any super-duper, really, really, REALLY small building blocks that make up a leaf?

Let’s take a look.


What do y’all see? What do you think are all those tiny parts inside the leaf?

I mean, I thought leaves were small already, didn’t you? But it’s like leaves are made up of tiny little green specks. Do y’all see the tiny little green specks? How many do you think there are inside one tiny leaf?

A million-bazillion-bajillion? Probably about that many. I actually just remembered. I learned about these tiny specks when I was in school. I know what they’re called! Do you want to know the name for those little dots inside the leaf?

These little specks are called molecules. Can y’all say that with me?

MOL-E-CULES. Let’s spell it out.

I realize that atoms are the true building blocks but we can get there eventually. For now, let’s hold off on the sub-molecular and sub-atomic particles.

Molecules make up everything. They make up leaves, but they also make up everything else in the world. Molecules even make up you — your hair, your teeth, your skin — it’s all made of molecules!

If we take thee same super-powerful microscope that we used on the leaf, and we pointed it at our fingers, or the blocks, or the carpet — do you think we would see those tiny specks again? Remember, those tiny specks are called molecules and they make up EVERYTHING. So would we see them in our skin?

Yes! Because molecules make up… everything! Right. They make up your skin, they make up that chair, they make up trees and leaves and sticks and dirt. They are the tiniest building blocks in nature and they build everything in the world.

But what about the computer? Do molecules make up the computer?

How about this marker? Do molecules make up this marker? If we looked close enough, would we see molecules?

Yes! Because molecules are the building blocks of everything! When nature wants to build something, it starts by putting molecules together. Even air and water are made up of molecules.

Let’s zoom in super close on some other things and see if we can see the molecules.

Wow. It’s so crazy how things look completely different when you zoom in on them. It’s like you can see the tiniest building blocks. And those building blocks are called…

Molecules! Yes, tell me again though — what are molecules?

Right, they are tiny speck building blocks! And where can we find molecules? Are they only in leaves or are they everywhere and in everything?

Everywhere yes! So you are made of molecules. And I am made of molecules. And your mom and dad — are they made of molecules too? Is your pet dog made of molecules? Is your house made of molecules?

If we look close enough, we’re all made of molecules!

When you‘re at lunch today, tell the lunch lady that your food is made of molecules. Your tray is made of molecules. Your milk is made of molecules.

When you go home, tell your parents that you are made of molecules. That your bed is made of molecules and your favorite toy is made of molecules.

I guarantee you they will be super impressed. They may ask: How do you know that? Where did you learn it?

And you can tell them: I used my big brain (that’s made of molecules)!

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This is probably the place to leave the lesson. There are more analogies and videos to help kids better understand the concept, but it’s better to save it for another time so we don’t overwhelm them. It will be hard enough for them to separate the idea that molecules make up a leaf vs. molecules make up everything.

A few notes on the pedagogy and repetitive style: The constant repetition of the same ideas and definitions keep kids focused on what we are talking about. High-level concepts and new ideas need constant reinforcement.

The more times you can say the definition in different contexts, the better the chances children will make the connections and retain the new information. Saying the definition in different ways, even slightly, will also resonate with different students’ learning styles. It’s easy to tune out so give them lots of chances to tune in. When they hear your enthusiasm and see the connection for themselves, they will have their “Wow-Cool” moments.

On top of the repeated definitions, I give lots of examples about molecules. I list items in the classroom, in the lunchroom, and at home. I tell them their favorite people and things are all made of molecules. This makes it relevant and it makes kids want to share a new fact about these people with them. If they go home and tell parents that they are made of molecules, that will for sure lock the idea in their heads.

The examples also help take the concept from one example to a bigger picture. Without them, children will probably keep thinking that molecules make up leaves and that’s it. They may not make the connection that molecules make up everything. The leaf-tree example is there to give them a relevant problem to solve, working from the block center to trees to leaves to a question about what parts make up the whole. It starts with a familiar situation for kids to get a handle on the big idea concepts on a micro-level (no pun intended). Once that’s in place, it’s time to pivot and switch to applying the concept at a macro-scale.


To reinforce the idea, bust out the sand sensory table at centers and leave some sandcastle molds and water nearby so kids can build using the sand. It’s always good to have some inspiration so showing a fun time-lapse sand castle video could be a good start.

When you come to the carpet, ask them: Did you have fun building with sand? Is sand big or small? Does the sand remind you of molecules?

We learned yesterday that molecules are the tiniest building blocks. They are just little specks, like we saw in the zoomed-in leaf. And sand, well that’s pretty teeny-tiny too!

Did you build your sand castles by stacking all those tiny specks on top of each other, one after the other? Or did you build it in big chunks with huge handfuls of sand? Let’s look at your finished amazing castles. Now does that look like a bunch of little specks, or does it look like a castle?

Right, it looks like a castle! Now what about a leaf? Does that look like a bunch of little specks put together, or does it look like a leaf? And look at your hand, does that look like a bunch of tiny specks or does it look like your hand?

Molecules are a lot like the sand you used to build your castle. You don’t need to focus on each grain of sand to build a castle.

When you look at your castle, you don’t say — wow, look at all my sand molecules. You say, look at my castle. Just like when I ask you to raise your hands, I don’t say, raise your hand molecules. But those molecules still make up the bigger thing because molecules are…

Building Blocks!

Y’all are some serious physicists.

And that’s how you can teach molecules to a 5-year-old.

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ELI10: Challenges and Extensions

Even sand is made of molecules. Check out this image of sand under a microscope:

In the right cultural context, this lesson from Tim Reid on WKRP will hit it out of the park. He teaches the makeup of an atom by comparing the relationships of neutrons, electrons, and protons to rival gangs in the same neighborhood.

How Sound Affects Molecules:

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