Which of the following is an indication that a substance has undergone a chemical change? no new product has been formed. the color of the substance has not changed. the original constitute has not changed. the molecular structure has changed. nextreset

Option (d) is the correct answer.

Explanation:

A change causes change in chemical composition of a substance is known as a chemical change.

For example, reactivity, toxicity, combustion etc are all chemical properties.

Chemical changes lead to the formation of new compounds. As a result, there occurs change in molecular structure of a compound.

Whereas a change that does not bring any changes in chemical composition of a substance is known as a physical change.

For example, boiling point, density, volume, melting point etc are all physical properties.

Thus, we can conclude that the molecular structure has changed is an indication that a substance has undergone a chemical change.