Which change is chemical?

Question

A. Water boiling: solid water becoming gaseous water
B. water evaporating: liquid water becoming gaseous water
C. Water freezing: liquid water becoming solid water
D. Water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules

Answer 1

The change that is chemical is:

D. Water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules.

In this process, water (H₂O) is decomposed into its elemental components, hydrogen (H₂) and oxygen (O₂), which are different substances from the original compound. The other options (A, B, and C) are physical changes, as they involve changes in states of matter without altering the chemical identity of water.