Describe what happens in a single replacement reaction. What can replace what?

The one element is substituted in place of other element in compound.

Explanation:

Single replacement:

It is the reaction in which one elements replace the other element in compound.

AB + C → AC + B

For example:

Consider the reaction between zinc and silver nitrate. In this chemical reaction the zinc is substituted in place of silver in silver nitrate compound.

Chemical equation:

2AgNO₃ + Zn → ZnNO₃ + 2Ag

The starting material consist of compound (AgNO₃) and pure element (Zn).

After reaction a new compound (ZnNO₃) and pure element (Ag) is generated.