Where do smells go? Do the particles just disperse into the air around it?



Where do smells go? Do the particles just disperse into the air around it?

In: Chemistry

They get diluted. And at one point, the molecules are so dilute and rare that the nose can no longer sense them against everything else that’s there.

In the long run, the molecules that make up the smell (like almost any other air contaminant) will be broken down by sunlight or caught in raindrops and deposited on the ground.

Basically yes. Heavy particles and gases may settle out to the floor, the rest just diffuse away into the atmosphere.

Try not to think too hard about what’s physically happening when you smell a fart.

Smells aren’t really particles, they’re vapors, molecules like terpenes and hydrocarbons. If they were condensed, they would be fast evaporating liquids. [Limonene](https://en.wikipedia.org/wiki/Limonene#:~:text=Limonene%20is%20a%20colorless%20liquid,flavoring%20agent%20in%20food%20manufacturing.) is a good example, it is lemon scent. [Skatole](https://en.wikipedia.org/wiki/Skatole) is another example, it is the main component of the smell of human shit.

They disperse into the atmosphere, and they eventually break down; they form smog (reactive chemical species that harm the lungs) before they break down. [Here’s an article about trees that release organic compounds that break down to ozone](https://www.scientificamerican.com/article/the-paradox-of-pollution-producing-trees/). Those organic compounds re similar to the things the nose perceives as smells.


Eventually they disperse so widely you don’t smell them.

They will also get stuck on solid object that won’t get near your nose.