In $\mathrm{CsCl}$ type structure, the coordination number of ${\mathrm{Cs}}^{+}$ and ${\mathrm{Cl}}^{-}$ respectively are:

The correct option is D

8,8

Explanation:

• The coordination number is defined as the number of the neighboring particles in a crystal.
• In Caesium chloride $\mathrm{CsCl}$, the cesium ions form the simple cubic arrangement and the chloride ions occupy the interstitial sites
• In $\mathrm{CsCl}$, each Cesium ion ${\mathrm{Cs}}^{+}$ is surrounded by $8$ chloride ions and each Chloride ion ${\mathrm{Cl}}^{-}$ would be surrounded by $8$ Cesium ions.
• Hence, the coordination for the $\mathrm{CsCl}$ type of structure is $8:8$.

Therefore, option (D) is the correct answer. In $\mathrm{CsCl}$ type structure, the coordination number of ${\mathrm{Cs}}^{+}$ and ${\mathrm{Cl}}^{-}$ respectively are $8,8$.