Question

When substances are different from the starting substances, ______ has occurred. a physical change a chemical change no change a mass change

Answer 1

A chemical change... But only if the process is irreversible

Answer 2

Answer : The correct option is, Chemical change.

Explanation :

Physical change : It is a change in which there is no new compound or substance is formed. In this, changes occurs only in the phase.  This change is reversible in nature.

For example : Water boiled  : It is a physical change because in this process only phase changes from liquid state to gaseous state.

Chemical change : It is a change in which a new or different compound or substance is formed and releases some amount of energy. There is no changes occurs in the phase. This change is irreversible in nature.

For example : Marshmallows browned  : It is a chemical change due to the burning of sugar. In the sugar burning process, sugar react with oxygen to give carbon dioxide and water as a product.

As per question, when the substances are different from the starting substances, chemical change has occurred.

Hence, the correct option is, Chemical change.