Why Do Cosmetics Smell? (on a molecular level)?

I am doing a secondary+ research paper for my chemistry class on why cosmetics smell, but im having trouble finding any good valid sources. if anyone can give me a reason on a molecular level it would be greatly appreciated, from there i can look it up and develop a more thorough reason, but anything is appreciated. It is due on June 4, 2007. HELP! and also, keep in mind that i am aware that the chemicals, oils etc are the reason it has an odor, i am looking for why those chemicals produce the odor. This may require some knowledge in biochemistry. THANK YOU SO MUCH!%26lt;3Why Do Cosmetics Smell? (on a molecular level)?
They evaporate, the molecules float through the air to receptor molecules in your nose, and you smell them.

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