An example of a chemical property is the?

The formation of rust on a metal is indeed an example of a chemical property because it involves a chemical reaction between the metal and oxygen in the presence of moisture, resulting in the formation of iron oxide. This process is not just a physical change; it alters the composition of the metal, signifying a chemical change. The creation of rust demonstrates how materials can change at the molecular level due to reactions, which is the essence of a chemical property.

The other options provided do not fit the definition of a chemical property. For instance, the formation of steam from water and the formation of ice from water are both physical changes, where water changes states but its chemical composition remains the same. Melting point, on the other hand, is a physical property that describes the temperature at which a solid becomes a liquid, also not involving any chemical transformation. Thus, the identification of rust formation highlights the distinction between physical changes and chemical properties effectively.