Here's why:
* Steam is water in its gaseous state. In this state, the water molecules are far apart and move freely.
* Hydrogen bonds form when a hydrogen atom is covalently linked to a highly electronegative atom (like oxygen) and is attracted to an electron pair on a nearby electronegative atom. This requires the molecules to be close enough for the attraction to occur.
* In steam, the molecules are too far apart for hydrogen bonds to form. They are constantly moving and colliding, but they don't stay close enough for a significant amount of time to form hydrogen bonds.
Important Note: While there are no hydrogen bonds in steam, there can be weak van der Waals forces between the water molecules. These forces are much weaker than hydrogen bonds and are based on temporary fluctuations in electron distribution.
