So here, let's take a look at this example question. It says which of the following is not a chemical property from an unknown element. Now remember a chemical properties associated with matter undergoing some type of chemical reaction where the composition, the chemical bonds and therefore the identity of our original substance is forever changed. If we take a look here at option a it says it has a yellow orange color. Now this is just talking about the appearance of the element the way it looks. And we haven't talked about it yet, but this represents a physical property, the way something looks is associated by its physical property. Now, even though we haven't talked about physical properties yet, we know that this could not be a chemical property because it's not talking about how that or yellow orange substance is reacting or involved in a chemical reaction. So, this would be our answer. This is not a chemical property. If we look at the other options, it is very soluble in an acid solution soluble, meaning we're dealing with soluble it. E. Which is one of our key chemical properties we talked about up above. So this would be a chemical property. It is radioactive, radioactive is also another chemical property. We've talked about. It experiences rusty when exposed to pure oxygen gas. So, we've been talking about this consistently that rusting of metals is an example of an irreversible process. It's an example of a chemical change. It has to do with oxygen from the air chemically binding to the metal. So this represents a chemical reaction and therefore a chemical property. It has a high reactivity with acids. So we're talking about its reactivity, which again, is another chemical property we talked about. So it would have to be the answer. It's what it doesn't represent a chemical property. It's talking about the appearance of the element, not necessarily its reactivity or its involvement in the type of chemical reaction. Now that we've seen this example, click on the next video and let's take a look at the practice question.