Volatility matters
A substance must enter the air in sufficient amount to reach receptors.
Mixtures create complex scents
Perfumes and foods contain many molecules with different evaporation rates.
Concentration changes perception
The same compound can smell different at different concentrations or in different mixtures.
Smell is partly interpretive
Context, memory and adaptation influence perception as well as chemistry.
This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.