Final answer:
A single-replacement reaction is a chemical reaction in which one element replaces a similar element in a compound. It can occur with metals replacing metals or nonmetals replacing nonmetals. These reactions are redox reactions due to the change in oxidation numbers.
Step-by-step explanation:
A single-replacement reaction, also known as a single-displacement reaction, is a chemical reaction in which one element replaces a similar element in a compound.
The general form of a single-replacement reaction is A + BC → AC + B. This reaction can occur when element A is a metal and replaces element B in the compound, or when element A is a nonmetal and replaces another nonmetal in a compound. Single-replacement reactions are redox reactions because they involve a change in oxidation numbers.