Petrol is kindve like this but it evaporates so quickly. What weighs less than petrol? Is the rate something evaporates related to the weight?
The rate at which something evaporates is determined by their atoms bond strength, weight has less importance. The reason petrol evaporates fast (and melts and boils at low temperatures) is because they only have London forces, which is the weakest weak bond.
So YOU took Dave!! We'll duel for it, at noon, be by the three pronged cactus. (You're welcome tho)
If you want to test it you could just seal your room, tape the windows and doors and keyholes, then let enough petrol evaporate until the air is saturated. Then you can test spilling it on the floor without fear of evaporation!