Please help! A drop of oil (volume 0.05 cm3) is released from a medicine dropper on to the calm surface of a pond where it spreads out to cover an area of 40 cm2. Assume that the oil film has a uniform thickness equal to the diameter of an oil molecule. Calculate the diameter of an oil molecule.

The volume of the drop has to be the area of the film x thickness.
Set area x thickness = given volume and solve for thickeness.

Thanks Bob I'll get to calculating!