When the bed is fluidized with liquids, it is known as ___________ fluidization, and with gas too it is known as ___________ fluidization.

Correct Answer: Homogeneous, Heterogeneous
When fluidised with a liquid, the interaction between solid and liquid is more effective due to the viscosity of the fluids, hence all the pellets are then in complete free fall state as compared to gases when the solids are always partially free. Hence when the bed is fluidized with liquids, it is known as homogeneous fluidization, and with gas it is known as heterogeneous fluidization.