In which of the following substances is the speed of molecules the highest?
A]ice
B]Kerosene
C]Sugar cube
D]Water vapour

Dear student, order is speed of molecules for.differeny state is solid < liquid < gas. Here, ice and sugar cube is solid. Kerosene is liquid. Water vapour is in gaseous phase. Hence, speed of molecules is highest in water vapour option (D) regards,