Which reaction type involves an element reacting with an ionic compound?

The type of reaction where an element reacts with an ionic compound is called a single replacement reaction. In this scenario, a single element displaces another element from an ionic compound. This results in the formation of a new ionic compound and the original element is released.

For instance, if a metal such as zinc is added to a solution of copper sulfate, zinc will displace copper, leading to the formation of zinc sulfate and the release of metallic copper. This clearly illustrates how one element can replace another within a compound, which is the hallmark of a single replacement reaction.

In contrast, other types of reactions like simple synthesis involve combining two or more reactants to form a single product, not the displacement of one element by another. Decomposition reactions involve breaking down a compound into simpler substances, and complex formation reactions generally describe the combination of substances into a more complex compound, often involving coordination of ions or molecules rather than the displacement of one element by another.

Thus, the unique mechanism of one element replacing another within an ionic compound defines single replacement reactions as the correct answer.