Which change is chemical?

Question

1. Water freezing, liquid water becoming solid water.
2. Water undergoing elextrolysis: liquid oxygen and hydrogen molecules.
3. Water evaporating: liquid water becoming gaseous water.
4. Water boiling: solid water becoming gaseous water

Answer 1

The change that is chemical among the options given is:

2. Water undergoing electrolysis: liquid oxygen and hydrogen molecules.

During electrolysis, water (H₂O) is broken down into its constituent elements, hydrogen (H₂) and oxygen (O₂), which is a chemical change because it alters the chemical composition of the substance.

The other options are physical changes, where the substance remains chemically the same, just changing states (solid, liquid, gas).