States of matter—solid, liquid, and gas—are important for figuring out if a change we see is physical or chemical.

1. Physical Changes: These happen when a substance changes its shape or state, but not what it's made of. Some examples are:
   • Ice melting into water.
   • Water boiling into steam.

In these cases, the state of matter changes, but the water remains H₂O (the same stuff) the whole time.

2. Chemical Changes: These happen when a substance changes into something new. For example:
   • When wood burns, it turns into ash and gas.
   • When iron rusts, it changes from metal to a different kind of substance.

Here, the original materials are changed in a big way, creating new products.

From what I've seen, you can notice these changes by watching how substances act. For instance, when you heat up sugar, it first melts. That’s a physical change. But if you keep heating it, it will change into caramel, which is a chemical change.

Learning to spot these changes can help you understand not just what happens in labs but also in everyday life. This makes science feel a lot more connected to our daily experiences!