Understanding Chemical and Physical Change for 9-Year-Olds

What is Change?

Every day, we see things change around us. Sometimes, these changes are big, and sometimes they are small. But did you know that there are two main types of changes? They are called chemical changes and physical changes.

What is a Physical Change?

A physical change is when something changes, but its chemical nature stays the same. This means that even if the appearance changes, the material is still the same inside.

Examples of Physical Changes:

• Melting Ice: When ice melts, it becomes water. The water is still H2O, but it just looks different.
• Cutting Paper: If you cut a piece of paper into smaller pieces, it's still paper.
• Mixing Colors: When you mix blue and yellow paint, you might get green paint, but it’s still paint.

What is a Chemical Change?

A chemical change happens when a substance transforms into something new. In this case, the molecules change, and you end up with a different material.

Examples of Chemical Changes:

• Burning Wood: When you burn wood, it turns into ash and smoke. Those are completely different things than the wood you started with.
• Rusting Iron: If you leave a metal out in the rain, it can rust and change color. That rust is a new material.
• Baking a Cake: When you mix ingredients and bake them, they change into something delicious and are no longer the separate ingredients.

How to Remember Them:

Think of it this way: If you can get the original thing back just by reversing the change (like melting ice back into ice), then it’s a physical change. But if you can’t get it back to the original (like ash from burnt wood), then it’s a chemical change.

Understanding these two types of changes can help you see the world in a new way! Every time you cook, play, or even do a science experiment, you're experiencing physical and chemical changes!