Areaction in which two ions switch places is which type of reaction?

double-displacement

single-displacement

synthesis

decomposition

A reaction in which two ions switch places is called double-displacement reaction.

Explanation:

Double displacement reaction usually takes place between two positive ions or two negative ions. When anions or cations of totally different compounds change places, two totally different compounds are formed.  

Syntax for double displacement reaction:

AB + CD --> AD + BC

It can also be defined in simple terms as the reaction in which exchange of ions takes place is called double displacement reaction.

The chemical reaction is as follows:

NaOH(aq) + HCl(aq)  --> NaCl(aq)  + H2O (l)

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).