Step-by-step explanation:
A property that changes chemical composition of a substance is known as chemical property.
For example, precipitation, reactivity, toxicity etc are chemical property.
A chemical change cannot be reverted back.
Hence, when paper is burned in air then combustion reaction is taking place which is a chemical reaction as it cannot be reverted back.
On the other hand, a property that does not bring any change in chemical composition of a substance are known as physical properties.
For example, shape, size, mass, volume, density, etc of a substance are all physical properties.
Thus, we can conclude that paper burns readily in air is a chemical property.