Question

The cells used in a wrist watch undergo:

• A. physical change
• B. periodic change
• C. chemical change
• D. none of the above

Answer 1

Answer: (C)

chemical change

Physical changes are reversible and, no new substance is formed. An example is the melting of ice. Periodic changes are the ones that occur after regular intervals of time. An example of periodic change is the beating of the heart. Chemical changes are irreversible. New substances are formed during a chemical change.

The Cells used in wristwatches are called button cells. These cells undergo chemical reactions to produce energy that is used in the functioning of the watch. Thus, option C is correct.