Chemical and physical properties are used to help identify substances. A substance's chemical properties identify whether or not that substance reacts with another substance or it can be said that a chemical property of a substance will helps in deciding whether the substance will react or not with another substance. To react with oxygen, the substance should have the ability to burn, the more quickly the substance burn, more readily the substance will burn to produce light and heat.
This can also be explained with the formation of rust on a chemical compound, The more readily the compound reacts with oxygen, more readily it undergoes rusting .
For example when iron kept in open air, it undergoes rust as it reacts with oxygen.