Substances are identified by the properties that they exhibit.  There are two broad classes of properties - chemical properties and physical properties. The chemical properties of a substance describe how that substance reacts (or doesn't react) with other substances. On the other hand, the physical properties of a substance describes characteristics and qualities of that substance that are independent of the manner in which it reacts with other substances.
 

Chemical vs. Physical Properties

Two of the properties are physical properties and the other is chemical property ... or vice versa. To know which property falls into which category, study the infographic below. Once you understand the distinction between chemical and physical properties, you're ready to identify the one property that doesn't belong.