A match is lit and held under a cold piece of metal. The following observations are made: (a) The match burns. (b) The metal gets warmer. (c) Water condenses on the metal. (d) Soot (carbon) is deposited on the metal. Which of these occurrences are due to physical changes, and which are due to chemical changes?

Key Concepts

Physical Changes

Physical changes are alterations that do not change the chemical composition of a substance. They involve changes in state, shape, or appearance, such as melting, freezing, or condensation. In the context of the question, the warming of the metal and the condensation of water are physical changes, as they do not involve a transformation of the substances involved.

Chemical Changes

Chemical changes involve a transformation that alters the chemical composition of a substance, resulting in the formation of new substances. This can include reactions such as combustion, where reactants are converted into products with different properties. In the scenario presented, the burning of the match and the deposition of soot are chemical changes, as they indicate a reaction that produces new materials.

Energy Transfer

Energy transfer is a fundamental concept in chemistry that describes how energy moves from one system to another, often during physical or chemical changes. In this case, the heat from the burning match is transferred to the metal, causing it to warm up. This energy transfer is crucial for understanding the interactions between the match and the metal, as well as the resulting changes observed.