What Happens During Chemical Reactions?

O

Owlo

Koko, you look like you've been on quite an adventure. There's something orange on your sleeve.

K

Koko

Oh! That's rust, Owlo. I was climbing the old metal fence near the garden, and it left marks all over me.

O

Owlo

Rust is actually a perfect example of something I've been wanting to talk to you about. Have you ever wondered why metal turns rusty in the first place?

K

Koko

I always thought it just got old and tired, like when my shoes wear out.

O

Owlo

That's a reasonable guess, but it's something far more interesting than just getting old. What's actually happening is a chemical reaction.

K

Koko

A chemical reaction? That sounds like something from a science movie.

O

Owlo

It does sound dramatic, doesn't it? But chemical reactions are happening all around us, every single day. Let's head to the science lab, and I'll show you what I mean.

O

Owlo

Here we go. Now, a chemical reaction is what happens when two or more substances combine and change into something completely new.

K

Koko

So the metal and something else combined to make rust? What did it combine with?

O

Owlo

Exactly right. Iron in the metal reacts with oxygen from the air, and water helps it along. Together, they create a brand new substance called iron oxide. That's rust.

K

Koko

So rust isn't just dirty metal. It's actually a whole new thing that didn't exist before.

O

Owlo

Precisely. And that's the key idea with chemical reactions. You start with ingredients called reactants, and you end up with something new called products.

K

Koko

Reactants and products. That sounds like a recipe, kind of.

O

Owlo

That is a brilliant way to think about it. Chemistry is very much like cooking. Let me show you a classic example right here in the lab.

K

Koko

Wait, is that baking soda and vinegar? My cousin showed me this once and it went everywhere.

O

Owlo

Yes, and we'll keep it over the tray this time. Watch what happens when I pour the vinegar in.

K

Koko

It's fizzing and bubbling like crazy! Where is all that gas coming from?

O

Owlo

The vinegar and baking soda react together and produce a gas called carbon dioxide. That's the bubbling you see. The liquid and powder are gone, and something new has formed.

K

Koko

So the baking soda and vinegar are the reactants, and the fizzy gas is the product?

O

Owlo

You've got it. And here's something important. Once a chemical reaction happens, you usually cannot simply reverse it. The new substance is different from what you started with.

K

Koko

Like how you can't un-bake a cake. Once it's baked, it's a cake forever.

O

Owlo

That is a perfect example, Koko. Baking is actually full of chemical reactions. Heat causes ingredients to change permanently into something new.

K

Koko

So every time my mom bakes, she's basically doing chemistry in the kitchen?

O

Owlo

Every single time. Digestion in your body is a chemical reaction too. Even the way leaves change color in autumn involves chemical reactions.

K

Koko

That's wild. I never thought chemistry was happening inside me right now.

O

Owlo

Your body is running hundreds of chemical reactions every second just to keep you alive. It's one of the most remarkable things about living creatures.

K

Koko

Okay, my brain is a little full right now. But in a good way.

O

Owlo

That means it's working perfectly. Before you go, I'd love to hear you put it all together. Can you tell me what you've learned today about chemical reactions?

K

Koko

Okay, so a chemical reaction is when two or more substances mix and turn into something completely new. The starting ingredients are called reactants, and the new stuff you get is called products. Once the reaction happens, you usually can't go back. Rust, fizzing vinegar, baking a cake, even digesting food — it's all chemistry. Basically, the whole world is one giant science experiment, and I've been walking around in it without even knowing.

O

Owlo

That is one of the best summaries I've ever heard. And I have heard quite a few over the years.

K

Koko

Next time I want to learn about explosions. For science reasons, obviously.

O

Owlo

We'll add that to the list, Koko. Right after we cover why you should never mix certain chemicals at home.