Question

In a ________ reaction, a single uncombined element replaces another element in a compound. synthesis double displacement single displacement

Answer 1

In a single displacement / replacement reaction a single uncombined element replaces another element in a compound.

Single replacement is type of chemical reaction where an element react with a compound and take the place of another element in that compound.
example of this type of reaction is
Zn+ 2HCl -----> Zncl2 + H2