Answer: Option (b) is the correct answer.
Explanation:
When any change in the chemical composition of a substance occurs then it is known as a chemical change.
For example, reactivity, toxicity, flammability, combustion etc are all chemical properties.
So, when sugar burns in air to form water and carbon dioxide then there occurs change in chemical composition of sugar. Therefore, chemical property of sugar also changes.
On the other hand, when there occurs no change in chemical composition of a substance then it is known as physical property.
For example, density, boiling point, freezing point etc are all physical properties.
Therefore, we can conclude that sugar burns in air to form water and carbon dioxide describe chemical properties.
