When an element displaces another element from its compound, a _____________ reaction occurs.

• When one compound of higher reactivity displaces another compound of low reactivity in a chemical reaction it is said to be a displacement reaction.
• As the name suggests, in displacement reaction one compound takes place of the other one.
• Displacement reaction: $\mathrm{AB}+\mathrm{C}\to \mathrm{AC}+\mathrm{B}$
• For example: $2\mathrm{NaBr}\left(\mathrm{aq}\right)+{\mathrm{Cl}}_2\left(\mathrm{aq}\right)\to 2\mathrm{NaCl}\left(\mathrm{aq}\right)+{\mathrm{Br}}_2\left(\mathrm{aq}\right)$

Therefore, when an element displaces another element from its compound, a displacement reaction occurs.