Final answer:
The substance from the given options that caused a physical change to the coin's surface is melting, as it changes the state of the substance without altering its chemical structure.
Step-by-step explanation:
The question is asking which substance produced a physical change on the surface of a coin. The options given are rusting, melting, tarnishing, and evaporation. Of these, melting is the process that is typically a physical change. When a substance such as a metal is melted, its state changes from solid to liquid, but its chemical composition remains the same. However, rusting and tarnishing are examples of chemical changes, where the chemical composition of the metal changes due to a reaction with substances in the environment. Evaporation is also a physical change, but it's not one that would typically occur on the surface of a coin. Therefore, the correct answer to the question is melting, as it changes the physical state without altering the coin's chemical makeup.