[azab41]

My question is kind of broad, but that's why i need some help.  Why is water unique? The instructor said that water is supposed to be frozen at room temp- but it's not...Why?    I know it has to do something with the density, and i'm also wondering if the answer lies in the fact that water condenses as it gets colder, but begins to expand before freezing at about 4 degrees celcius.  
Thanks for the help upfront.
 

[jdurg]

It's simply the hydrogen bonding which occurs between separate molecules of water.  The molecule itself is VERY polar, so "charges" develop on each side of the molecule.  This causes all kinds of strange things to happen which really shouldn't based upon other characteristics of dihydrogen monoxide.  Thankfully, those "oddities" occur otherwise life as we know it would fail to exist.