Vapor is a is a substance in the gas phase at a temperature lower than its critical temperature. Which means in case of water: small particles of water ( lets say a **collection of molecules held together** having a mass ) leaves the water surface in to the air.

Archimedes' principle states that the **upward buoyant force** = **weight of the fluid** that the body displaces

So the **upward buoyant force on the water particle** ( Which is vapor ) = **weight of the air it displaces**

We know that **density of water** **>** **density of air. **

So **weight of the water particle > weight of the air it displaces**

Which means **weight of the water particle > ****upward buoyant force on it**

So when you consider the equilibrium of the water particle; it going upwards is against Newton's laws.

Can someone please enlighten me on this ?

Thanks a lot.