Which one among the following is an example of chemical change ?

A chemical change occurs when one or more new substances are formed through a chemical reaction, often involving the rearrangement of atoms [2]. Cooking and frying are classic examples of chemical changes because they involve irreversible processes like protein denaturation, which creates new substances with different properties [1]. In contrast, physical changes only alter the state, shape, or size of a substance without changing its chemical identity [1]. The melting of an ice cube and the boiling of gasoline are phase changes (solid to liquid and liquid to gas, respectively), which are classified as physical changes [2]. Similarly, the attraction of an iron nail to a magnet is a physical property and does not result in a new chemical substance, making it a physical change. Therefore, frying an egg is the only chemical change among the options.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 5: Changes Around Us: Physical and Chemical > In a Nutshell > p. 68
2. [2] https://www.nps.gov/teachers/classrooms/physical-chemical-changes-in-matter.htm