Do smells travel up or down?
Then, do smells rise or sink?
This is because the compounds you are smelling are entering the air, making their way up your nose, to your olfactory system. So, from this perspective it rises. Whether the scent sinks or rises depends on the mass of the source of the smell. To answer your question specifically, no, scent does not have weight or mass.
Moreover, how does smell travel?
Smells travel through the air by a process called diffusion; air particles, and the odour particles within the air, move freely in all directions. They are constantly moving and eventually they spread out through the air around them.
If we assume that the average mass of air (since it is a mixture of different gases) is 28.9 g/mol (or each gas particle is around 4.799*10-26), and room- temperature is 27C or 300K, we find that the average velocity of a single air particle is around 500 meter/sec or 1800 km per hour.