what is the physical propery of odor

Question

 what is the phisical properties of oder

Answer 1

Odors are small organic molecules in the air, dilute gases that humans/animals have olfactory receptors for. They are usually the breakdown products of organic materials. The OF receptors (chemical receptors in our nose) sense certain compounds and send pleasant/unpleasant signals to our brain.

Answer 2

Note the disparity in spelling quality between the title and the body of the question!!  

My Physics teacher once answered this question--odor is carried by organic material that stimulates or is sensed through the nose.  I hope that you don't think this answer stinks.