Physical vs. Chemical Changes: Same Stuff or New Stuff?

Hey there, scientist! I'm Atlas, and today we're going to figure out something really cool: when matter changes, does it stay the same stuff — or turn into brand-new stuff? Imagine you cut a piece of paper in half. You now have two pieces, but guess what? It's still paper! You could even tape it back together. That's a **physical change** — the shape or size changes, but the substance (what it's made of) stays the same. Melting is the same idea. An ice cube melts into liquid water, but it's still water — just a different form. You can even freeze it back! Now imagine that same paper catching fire. After it burns, you have ash and smoke — not paper anymore. Something brand new was made. That's a **chemical change** — the original substance is gone and one or more new substances have formed. Here's a handy clue list for chemical changes: look for a color change that can't be reversed, a new smell, bubbles of gas, flames or a glow coming from the materials themselves (not just an outside heat source), or something you can't easily undo. Rusting is a chemical change too — iron reacts with oxygen and water (moisture) in the air and turns into rust, which is a completely different substance. Remember: physical change = same substance, new shape or form. Chemical change = new substance is made. When in doubt, ask yourself: 'Can I get the original stuff back easily?' If yes, it's probably physical. If no — something new was born!