Chemical Reactions Hatch a Rubber Egg

Hmm....do you mean that a solid can change into a liquid or a gas?

Yes, heat melts solid ice and causes it to change to water. Heat also causes water to evaporate and become a gas.

We are studying how matter can change states!

You are both correct! Heat can cause
both reversible and irreversible chemical reactions.

But.. if I accidentally burn my toast in the toaster, I cannot reverse it.

Chemicals can also cause a change in the state of matter – for example, 
acetic acid found in vinegar.

Lemon juice is an acid too. I remember testing it with pH paper in 4th grade!

Can we do an experiment to learn more about chemical reactions?

Pay close attention. Watch what happens to the egg shell. 

That's right, Tilly! 
The acid reacts with the calcium carbonate shell. As the shell dissolves, it forms carbon dioxide gas.

Hey, I see BUBBLES
in my glass!
They're filled with gas...right?