Question

matter conservations matters quick check
which change is chemical? (1 point)
water freezing: liquid water becoming solid water
water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules
water boiling: solid water becoming gaseous water
water evaporating: liquid water becoming gaseous water

Explanation:

To determine a chemical change, we check if new substances are formed.

• Water freezing (liquid to solid) is a physical change (state change, same substance $\ce{H2O}$).
• Water undergoing electrolysis: $\ce{2H2O(l) -> 2H2(g) + O2(g)}$ forms new substances (hydrogen and oxygen), so it's a chemical change.
• Water boiling (solid to gas) and evaporating (liquid to gas) are physical changes (state changes, no new substances).

Answer:

B. water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules (assuming the options are labeled A, B, C, D with this as one of them; if original labels differ, adjust to the correct label with this description)