Final answer:
The weak bases in the given list are NH3 (ammonia), Na2CO3 (sodium carbonate), and CsOH (cesium hydroxide).
Step-by-step explanation:
The weak bases in the given list are NH3 (ammonia), Na2CO3 (sodium carbonate), and CsOH (cesium hydroxide).
Ammonia (NH3) is a weak base because it only partially dissociates in water, producing a small amount of hydroxide ions (OH-) and ammonium ions (NH4+).
Sodium carbonate (Na2CO3) is a weak base because the carbonate ion (CO3^2-) reacts with water to produce hydroxide ions (OH-).
Cesium hydroxide (CsOH) is a strong base because it is a compound of a strong alkali metal with hydroxide ion.