Which of the following represents a chemical reaction?*1 pointA) Melting of iceB) Rusting of ironC) Dissolving salt in waterD) Cutting paper into pieces

The correct answer is B) Rusting of iron.

This is because a chemical reaction involves a process that leads to the transformation of one set of chemical substances to another. In the case of rusting of iron, iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust. This is a chemical change as new substances are formed and the process is not easily reversible.

On the other hand, options A, C, and D are physical changes, not chemical reactions. Melting of ice involves a change of state from solid to liquid, but it's still water in both states. Dissolving salt in water is a physical change because the salt and water can be separated again by evaporation. Cutting paper into pieces is also a physical change because the paper's composition doesn't change, only its shape and size.