Final answer:
Burning wood is an example of a chemical change because it results in the formation of new substances such as ash, smoke, and various gases, altering the chemical composition of the original material.
Step-by-step explanation:
The question asks for an example that provides evidence of a chemical change. Among the options provided, the correct answer is Wood releases ash and smoke when burned. This is because burning wood involves a chemical reaction where the wood reacts with oxygen, leading to new substances such as carbon dioxide, water vapor, ash, and various other gases. This process is a clear indication of a chemical change occurring due to the transformation of the original substances into different substances with new chemical properties.
Other examples of chemical changes include the rusting of metal, where iron reacts with oxygen and water to form iron oxide (rust), and the burning of natural gas in a furnace, where methane (CH4) reacts with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O).
The other options given, like rock particles separating or sugar dissolving in water, are examples of physical changes, where no new substances are formed.