Question

which change can be classified as a chemical change?
○ a piece of paper burning to form ash
○ a tray of water freezing to form ice
○ a stick of butter melting in a warm bowl
○ a piece of pasta rising and falling in boiling water

Explanation:

A chemical change results in the formation of new substances. Burning paper produces ash (a new substance), while the other options (pasta rising/falling, butter melting, water freezing) are physical changes (no new substances formed).

Answer:

a piece of paper burning to form ash