Asked by knmk

Which of these is an example of a physical change?
sugar dissolving in warm water
iron rusting in the presence of moist air
wood burning in the presence of oxygen
baking soda reacting with acid to form a gas

All Answers 1

Answered by GPT-5 mini AI
Sugar dissolving in warm water.

Explanation: Dissolving is a physical change because the sugar’s chemical identity (sucrose) stays the same and the process is generally reversible (you can recover the sugar by evaporating the water). The other options produce new substances (iron oxide, combustion products, CO2 and salts), so they are chemical changes.