 Okay, let's try this one. Which of the following is NOT a chemical change? Okay, so can anybody tell me right away? Boiling water. Boiling water. What kind of change is that? Physical change. Physical change, right? So it's this one. So what, how do we know that if, oh so everybody probably knows this is a physical change. That's why they know these other ones are, are chemical changes, right? So what about a chemical change makes it a chemical change? We'll ask that question. It changes the chemical structure. The chemical structure, right? So what is that, what's another way to say it? It's like, do we can't change the chemical structure when we went from liquid water to gaseous water? It can't be changed back. Yeah, that's still a good way to think about it. Yeah, you can't change it directly back again, okay? So when I burn up coal, can I take that carbon dioxide that I burned up and take it immediately back to coal? No. No, no. If I boil an egg, can I take that hard-boiled egg and make it back into a non-boiled egg? No. No, it ain't gonna happen, right? And what about making bread rise using baking soda? Can I make the bread go flat again if I take the baking soda away? No. Because the baking soda is already reacted with the bread, it's made carbon dioxide, and that's what makes the baking soda puff up, okay? So are there any questions on chemical physical change? Okay, wonderful. Remember, the three that aren't boxed are chemical changes. The one that is is the physical change.